Added getXxxxx() methods that return Java 8 Streams.

src/main/java/org/gitlab4j/api/GroupApi.java

@@ -3,6 +3,7 @@ package org.gitlab4j.api;
 import java.util.Date;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -28,20 +29,19 @@ public class GroupApi extends AbstractApi {
     /**
      * Get a list of groups. (As user: my groups, as admin: all groups)
      *
-     * GET /groups
+     * <pre><code>GitLab Endpoint: GET /groups</code></pre>
      *
      * @return the list of groups viewable by the authenticated user
      * @throws GitLabApiException if any exception occurs
      */
     public List<Group> getGroups() throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "groups");
-        return (response.readEntity(new GenericType<List<Group>>() {}));
+        return (getGroups(getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of groups (As user: my groups, as admin: all groups) and in the specified page range.
      *
-     * GET /groups
+     * <pre><code>GitLab Endpoint: GET /groups</code></pre>
      *
      * @param page the page to get
      * @param perPage the number of Group instances per page
@@ -56,7 +56,7 @@ public class GroupApi extends AbstractApi {
     /**
      * Get a Pager of groups. (As user: my groups, as admin: all groups)
      *
-     * GET /groups
+     * <pre><code>GitLab Endpoint: GET /groups</code></pre>
      *
      * @param itemsPerPage the number of Group instances that will be fetched per page
      * @return the list of groups viewable by the authenticated user
@@ -66,6 +66,18 @@ public class GroupApi extends AbstractApi {
         return (new Pager<Group>(this, Group.class, itemsPerPage, null, "groups"));
     }
 
+    /**
+     * Get a Stream of groups. (As user: my groups, as admin: all groups)
+     *
+     * <pre><code>GitLab Endpoint: GET /groups</code></pre>
+     *
+     * @return a Stream of groups viewable by the authenticated user
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Group> getGroupsStream() throws GitLabApiException {
+        return (getGroups(getDefaultPerPage()).stream());
+    }
+
     /**
      * Get all groups that match your string in their name or path.
      *
@@ -74,9 +86,7 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Group> getGroups(String search) throws GitLabApiException {
-        Form formData = new GitLabApiForm().withParam("search", search).withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "groups");
-        return (response.readEntity(new GenericType<List<Group>>() {}));
+        return (getGroups(search, getDefaultPerPage()).all());
     }
 
     /**
@@ -107,10 +117,21 @@ public class GroupApi extends AbstractApi {
         return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups"));
     }
 
+    /**
+     * Get all groups that match your string in their name or path as a Stream.
+     *
+     * @param search the group name or path search criteria
+     * @return a Stream containing matching Group instances
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Group> getGroupsStream(String search) throws GitLabApiException {
+        return (getGroups(search, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a list of visible direct subgroups in this group.
      *
-     * <p><code>GET /groups/:id/subgroups</code></p>
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
      * @param groupId the group ID to get the sub groups for
      * @return a List&lt;Group&gt; containing the group's sub-groups
@@ -118,13 +139,42 @@ public class GroupApi extends AbstractApi {
      * @since GitLab 10.3.0
      */
     public List<Group> getSubGroups(Integer groupId) throws GitLabApiException {
-        return (getSubGroups(groupId, null, null, null, null, null, null, null, 1, getDefaultPerPage()));
+        return (getSubGroups(groupId, getDefaultPerPage()).all());
+    }
+
+    /**
+     * Get a Pager of visible direct subgroups in this group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
+     *
+     * @param groupId the group ID to get the sub groups for
+     * @param itemsPerPage the number of Group instances that will be fetched per page
+     * @return a Pager containing matching Group instances
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 10.3.0
+     */
+    public Pager<Group> getSubGroups(Integer groupId, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Group>(this, Group.class, itemsPerPage, null, "groups", groupId, "subgroups"));
+    }
+
+    /**
+     * Get a Stream of visible direct subgroups in this group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
+     *
+     * @param groupId the group ID to get the sub groups for
+     * @return a Stream&lt;Group&gt; containing the group's sub-groups
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 10.3.0
+     */
+    public Stream<Group> getSubGroupsStream(Integer groupId) throws GitLabApiException {
+        return (getSubGroups(groupId, getDefaultPerPage()).stream());
     }
 
     /**
      * Get a list of visible direct subgroups in this group.
      *
-     * <p><code>GET /groups/:id/subgroups</code></p>
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
      * @param groupId the group ID to get the sub groups for
      * @param skipGroups skip the group IDs passed
@@ -140,13 +190,13 @@ public class GroupApi extends AbstractApi {
      */
     public List<Group> getSubGroups(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
             GroupOrderBy orderBy, SortOrder sortOrder, Boolean statistics, Boolean owned) throws GitLabApiException {
-        return (getSubGroups(groupId, skipGroups, allAvailable, search, orderBy, sortOrder, statistics, owned, 1, getDefaultPerPage()));
+        return (getSubGroups(groupId, skipGroups, allAvailable, search, orderBy, sortOrder, statistics, owned, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of visible direct subgroups in this group.
      *
-     * <p><code>GET /groups/:id/subgroups</code></p>
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
      * @param groupId the group ID to get the sub groups for
      * @param skipGroups skip the group IDs passed
@@ -182,22 +232,7 @@ public class GroupApi extends AbstractApi {
     /**
      * Get a Pager of visible direct subgroups in this group.
      *
-     * <p><code>GET /groups/:id/subgroups</code></p>
-     *
-     * @param groupId the group ID to get the sub groups for
-     * @param itemsPerPage the number of Group instances that will be fetched per page
-     * @return a Pager containing matching Group instances
-     * @throws GitLabApiException if any exception occurs
-     * @since GitLab 10.3.0
-     */
-    public Pager<Group> getSubGroups(Integer groupId, int itemsPerPage) throws GitLabApiException {
-        return (new Pager<Group>(this, Group.class, itemsPerPage, null, "groups", groupId, "subgroups"));
-    }
-
-    /**
-     * Get a Pager of visible direct subgroups in this group.
-     *
-     * <p><code>GET /groups/:id/subgroups</code></p>
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
      * @param groupId the group ID to get the sub groups for
      * @param skipGroups skip the group IDs passed
@@ -225,10 +260,32 @@ public class GroupApi extends AbstractApi {
         return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups", groupId, "subgroups"));
     }
 
+    /**
+     * Get a Stream of visible direct subgroups in this group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
+     *
+     * @param groupId the group ID to get the sub groups for
+     * @param skipGroups skip the group IDs passed
+     * @param allAvailable show all the groups you have access to (defaults to false for authenticated users)
+     * @param search return the list of authorized groups matching the search criteria
+     * @param orderBy order groups by NAME or PATH. Default is NAME
+     * @param sortOrder order groups in ASC or DESC order. Default is ASC
+     * @param statistics include group statistics (admins only)
+     * @param owned limit to groups owned by the current user
+     * @return a Stream&lt;Group&gt; of the matching subgroups
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 10.3.0
+     */
+    public Stream<Group> getSubGroupsStream(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
+            GroupOrderBy orderBy, SortOrder sortOrder, Boolean statistics, Boolean owned) throws GitLabApiException {
+        return (getSubGroups(groupId, skipGroups, allAvailable, search, orderBy, sortOrder, statistics, owned, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a list of projects belonging to the specified group ID and filter.
      *
-     * GET /groups/:id/projects
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
      * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param filter the GroupProjectsFilter instance holding the filter values for the query
@@ -236,15 +293,13 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Project> getProjects(Object groupIdOrPath, GroupProjectsFilter filter) throws GitLabApiException {
-        GitLabApiForm formData = filter.getQueryParams();
-        Response response = get(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "projects");
-        return (response.readEntity(new GenericType<List<Project>>() {}));
+        return (getProjects(groupIdOrPath, filter, getDefaultPerPage()).all());
     }
 
     /**
      * Get a Pager of projects belonging to the specified group ID and filter.
      *
-     * GET /groups/:id/projects
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
      * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param filter the GroupProjectsFilter instance holding the filter values for the query
@@ -257,100 +312,101 @@ public class GroupApi extends AbstractApi {
         return (new Pager<Project>(this, Project.class, itemsPerPage, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "projects"));
     }
 
+    /**
+     * Get a Stream of projects belonging to the specified group ID and filter.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param filter the GroupProjectsFilter instance holding the filter values for the query
+     * @return a Stream containing Project instances that belong to the group and match the provided filter
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Project> getProjectsStream(Object groupIdOrPath, GroupProjectsFilter filter) throws GitLabApiException {
+        return (getProjects(groupIdOrPath, filter, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a list of projects belonging to the specified group ID.
      *
-     * GET /groups/:id/projects
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
-     * @param groupId the group ID to list the projects for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @return a list of projects belonging to the specified group ID
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Project> getProjects(int groupId) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "groups", groupId, "projects");
-        return (response.readEntity(new GenericType<List<Project>>() {}));
+    public List<Project> getProjects(Object groupIdOrPath) throws GitLabApiException {
+        return (getProjects(groupIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of projects belonging to the specified group ID in the specified page range.
      *
-     * GET /groups/:id/projects
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
-     * @param groupId the group ID to list the projects for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param page the page to get
      * @param perPage the number of Project instances per page
      * @return a list of projects belonging to the specified group ID in the specified page range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Project> getProjects(int groupId, int page, int perPage) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", groupId, "projects");
+    public List<Project> getProjects(Object groupIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", getGroupIdOrPath(groupIdOrPath), "projects");
         return (response.readEntity(new GenericType<List<Project>>() {}));
     }
 
     /**
      * Get a Pager of projects belonging to the specified group ID.
      *
-     * GET /groups/:id/projects
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
-     * @param groupId the group ID to list the projects for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param itemsPerPage the number of Project instances that will be fetched per page
      * @return a Pager of projects belonging to the specified group ID
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Project> getProjects(int groupId, int itemsPerPage) throws GitLabApiException {
-        return (new Pager<Project>(this, Project.class, itemsPerPage, null, "groups", groupId, "projects"));
+    public Pager<Project> getProjects(Object groupIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Project>(this, Project.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "projects"));
     }
 
     /**
-     * Get all details of a group.
+     * Get a Stream of projects belonging to the specified group ID.
      *
-     * GET /groups/:id
+     * <pre><code>GitLab Endpoint: GET /groups/:id/projects</code></pre>
      *
-     * @param groupId the group ID to get
-     * @return the Group instance for the specified group ID
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @return a Stream of projects belonging to the specified group ID
      * @throws GitLabApiException if any exception occurs
      */
-    public Group getGroup(Integer groupId) throws GitLabApiException {
-        return getGroup(groupId.toString());
-    }
-
-    /**
-     * Get all details of a group as an Optional instance.
-     *
-     * GET /groups/:id
-     *
-     * @param groupId the group ID to get
-     * @return the Group for the specified group ID as an Optional instance
-     */
-    public Optional<Group> getOptionalGroup(Integer groupId) {
-        return (getOptionalGroup(groupId.toString()));
+    public Stream<Project> getProjectsStream(Object groupIdOrPath) throws GitLabApiException {
+        return (getProjects(groupIdOrPath, getDefaultPerPage()).stream());
     }
 
     /**
      * Get all details of a group.
      *
-     * GET /groups/:id
+     * <pre><code>GitLab Endpoint: GET /groups/:id</code></pre>
      *
-     * @param groupPath the path of the group to get details for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @return the Group instance for the specified group path
      * @throws GitLabApiException if any exception occurs
      */
-    public Group getGroup(String groupPath) throws GitLabApiException {
-      Response response = get(Response.Status.OK, null, "groups", urlEncode(groupPath));
+    public Group getGroup(Object groupIdOrPath) throws GitLabApiException {
+      Response response = get(Response.Status.OK, null, "groups", getGroupIdOrPath(groupIdOrPath));
       return (response.readEntity(Group.class));
     }
 
     /**
      * Get all details of a group as an Optional instance.
      *
-     * GET /groups/:id
+     * <pre><code>GitLab Endpoint: GET /groups/:id</code></pre>
      *
-     * @param groupPath the path of the group to get details for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @return the Group for the specified group path as an Optional instance
      */
-    public Optional<Group> getOptionalGroup(String groupPath) {
+    public Optional<Group> getOptionalGroup(Object groupIdOrPath) {
         try {
-            return (Optional.ofNullable(getGroup(groupPath)));
+            return (Optional.ofNullable(getGroup(groupIdOrPath)));
         } catch (GitLabApiException glae) {
             return (GitLabApi.createOptionalFromException(glae));
         }
@@ -359,7 +415,7 @@ public class GroupApi extends AbstractApi {
     /**
      * Creates a new project group. Available only for users who can create groups.
      *
-     * POST /groups
+     * <pre><code>GitLab Endpoint: POST /groups</code></pre>
      *
      * @param name the name of the group to add
      * @param path the path for the group
@@ -391,7 +447,7 @@ public class GroupApi extends AbstractApi {
     /**
      * Creates a new project group. Available only for users who can create groups.
      *
-     * POST /groups
+     * <pre><code>GitLab Endpoint: POST /groups</code></pre>
      *
      * @param name the name of the group to add
      * @param path the path for the group
@@ -421,7 +477,7 @@ public class GroupApi extends AbstractApi {
     /**
      * Updates a project group. Available only for users who can create groups.
      *
-     * PUT /groups
+     * <pre><code>GitLab Endpoint: PUT /groups</code></pre>
      *
      * @param group to update
      * @return updated group instance
@@ -441,11 +497,11 @@ public class GroupApi extends AbstractApi {
     }
 
     /**
-     * Updates a  project group. Available only for users who can create groups.
+     * Updates a project group. Available only for users who can create groups.
      *
-     * PUT /groups
+     * <pre><code>GitLab Endpoint: PUT /groups</code></pre>
      *
-     * @param groupId the ID of the group to update
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param name the name of the group to add
      * @param path the path for the group
      * @param description (optional) - The group's description
@@ -456,7 +512,7 @@ public class GroupApi extends AbstractApi {
      * @return the updated Group instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Group updateGroup(Integer groupId, String name, String path, String description, Visibility visibility,
+    public Group updateGroup(Object groupIdOrPath, String name, String path, String description, Visibility visibility,
             Boolean lfsEnabled, Boolean requestAccessEnabled, Integer parentId) throws GitLabApiException {
 
         Form formData = new GitLabApiForm()
@@ -467,14 +523,14 @@ public class GroupApi extends AbstractApi {
                 .withParam("lfs_enabled", lfsEnabled)
                 .withParam("request_access_enabled", requestAccessEnabled)
                 .withParam("parent_id", isApiVersion(ApiVersion.V3) ? null : parentId);
-        Response response = put(Response.Status.OK, formData.asMap(), "groups", groupId);
+        Response response = put(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath));
         return (response.readEntity(Group.class));
     }
 
     /**
      * Creates a new project group. Available only for users who can create groups.
      *
-     * POST /groups
+     * <pre><code>GitLab Endpoint: POST /groups</code></pre>
      *
      * @param name the name of the group to add
      * @param path the path for the group
@@ -513,9 +569,9 @@ public class GroupApi extends AbstractApi {
     /**
      * Updates a project group. Available only for users who can create groups.
      *
-     * PUT /groups
+     * <pre><code>GitLab Endpoint: PUT /groups</code></pre>
      *
-     * @param groupId the ID of the group to update
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param name the name of the group to add
      * @param path the path for the group
      * @param description (optional) - The group's description
@@ -528,10 +584,10 @@ public class GroupApi extends AbstractApi {
      * @param sharedRunnersMinutesLimit (optional) - (admin-only) Pipeline minutes quota for this group
      * @return the updated Group instance
      * @throws GitLabApiException if any exception occurs
-     * @deprecated  Will be removed in version 5.0, replaced by {@link #updateGroup(Integer, String, String, String,
+     * @deprecated  Will be removed in version 5.0, replaced by {@link #updateGroup(Object, String, String, String,
      *      Visibility, Boolean, Boolean, Integer)}
      */
-    public Group updateGroup(Integer groupId, String name, String path, String description, Boolean membershipLock,
+    public Group updateGroup(Object groupIdOrPath, String name, String path, String description, Boolean membershipLock,
             Boolean shareWithGroupLock, Visibility visibility, Boolean lfsEnabled, Boolean requestAccessEnabled,
             Integer parentId, Integer sharedRunnersMinutesLimit) throws GitLabApiException {
 
@@ -546,111 +602,106 @@ public class GroupApi extends AbstractApi {
                 .withParam("request_access_enabled", requestAccessEnabled)
                 .withParam("parent_id", parentId)
                 .withParam("shared_runners_minutes_limit", sharedRunnersMinutesLimit);
-        Response response = put(Response.Status.OK, formData.asMap(), "groups", groupId);
+        Response response = put(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath));
         return (response.readEntity(Group.class));
     }
 
     /**
      * Removes group with all projects inside.
      *
-     * DELETE /groups/:id
+     * <pre><code>GitLab Endpoint: DELETE /groups/:id</code></pre>
      *
-     * @param groupId the group ID to delete
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteGroup(Integer groupId) throws GitLabApiException {
-
-        if (groupId == null) {
-            throw new RuntimeException("groupId cannot be null");
-        }
-
+    public void deleteGroup(Object groupIdOrPath) throws GitLabApiException {
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, null, "groups", groupId);
-    }
-
-    /**
-     * Removes group with all projects inside.
-     *
-     * DELETE /groups/:id
-     *
-     * @param group the Group instance to delete
-     * @throws GitLabApiException if any exception occurs
-     */
-    public void deleteGroup(Group group) throws GitLabApiException {
-        deleteGroup(group.getId());
+        delete(expectedStatus, null, "groups", getGroupIdOrPath(groupIdOrPath));
     }
 
     /**
      * Get a list of group members viewable by the authenticated user.
      *
-     * GET /groups/:id/members
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members</code></pre>
      *
-     * @param groupId the group ID to list the members for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @return a list of group members viewable by the authenticated user
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Member> getMembers(int groupId) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "groups", groupId, "members");
-        return (response.readEntity(new GenericType<List<Member>>() {}));
+    public List<Member> getMembers(Object groupIdOrPath) throws GitLabApiException {
+        return (getMembers(groupIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of group members viewable by the authenticated user in the specified page range.
      *
-     * GET /groups/:id/members
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members</code></pre>
      *
-     * @param groupId the group ID to list the members for
+     *@param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param page the page to get
      * @param perPage the number of Member instances per page
      * @return a list of group members viewable by the authenticated user in the specified page range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Member> getMembers(int groupId, int page, int perPage) throws GitLabApiException {
-        Response response = get(Response.Status.OK,  getPageQueryParams(page, perPage), "groups", groupId, "members");
+    public List<Member> getMembers(Object groupIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", getGroupIdOrPath(groupIdOrPath), "members");
         return (response.readEntity(new GenericType<List<Member>>() {}));
     }
 
     /**
      * Get a Pager of group members viewable by the authenticated user.
      *
-     * GET /groups/:id/members
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members</code></pre>
      *
-     * @param groupId the group ID to list the members for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param itemsPerPage the number of Member instances that will be fetched per page
      * @return a list of group members viewable by the authenticated user
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Member> getMembers(int groupId, int itemsPerPage) throws GitLabApiException {
-        return (new Pager<Member>(this, Member.class, itemsPerPage, null, "groups", groupId, "members"));
+    public Pager<Member> getMembers(Object groupIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Member>(this, Member.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "members"));
+    }
+
+    /**
+     * Get a Stream of group members viewable by the authenticated user.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @return a Stream of group members viewable by the authenticated user
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Member> getMembersStream(Object groupIdOrPath) throws GitLabApiException {
+        return (getMembers(groupIdOrPath, getDefaultPerPage()).stream());
     }
 
     /**
      * Get a group member viewable by the authenticated user.
      *
-     * GET /groups/:id/members/:id
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members/:id</code></pre>
      *
-     * @param groupId the group ID to get the member for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param userId the member ID of the member to get
      * @return a member viewable by the authenticated user
      * @throws GitLabApiException if any exception occurs
      */
-    public Member getMember(int groupId, int userId) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "groups", groupId, "members", userId);
+    public Member getMember(Object groupIdOrPath, int userId) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "groups", getGroupIdOrPath(groupIdOrPath), "members", userId);
         return (response.readEntity(new GenericType<Member>() {}));
     }
 
     /**
      * Get a group member viewable by the authenticated user as an Optional instance.
      *
-     * GET /groups/:id/members/:id
+     * <pre><code>GitLab Endpoint: GET /groups/:id/members/:id</code></pre>
      *
-     * @param groupId the group ID to get the member for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param userId the member ID of the member to get
      * @return a member viewable by the authenticated user as an Optional instance
      */
-    public Optional<Member> getOptionalMember(int groupId, int userId) {
+    public Optional<Member> getOptionalMember(Object groupIdOrPath, int userId) {
         try {
-            return (Optional.ofNullable(getMember(groupId, userId)));
+            return (Optional.ofNullable(getMember(groupIdOrPath, userId)));
         } catch (GitLabApiException glae) {
             return (GitLabApi.createOptionalFromException(glae));
         }
@@ -659,149 +710,149 @@ public class GroupApi extends AbstractApi {
     /**
      * Adds a user to the list of group members.
      *
-     * POST /groups/:id/members
+     * <pre><code>GitLab Endpoint: POST /groups/:id/members</code></pre>
      *
-     * @param groupId the project ID to add the member to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param userId the user ID of the member to add, required
      * @param accessLevel the access level for the new member, required
      * @return a Member instance for the added user
      * @throws GitLabApiException if any exception occurs
      */
-    public Member addMember(Integer groupId, Integer userId, Integer accessLevel) throws GitLabApiException {
-        return (addMember(groupId, userId, accessLevel, null));
+    public Member addMember(Object groupIdOrPath, Integer userId, Integer accessLevel) throws GitLabApiException {
+        return (addMember(groupIdOrPath, userId, accessLevel, null));
     }
 
     /**
      * Adds a user to the list of group members.
      *
-     * POST /groups/:id/members
+     * <pre><code>GitLab Endpoint: POST /groups/:id/members</code></pre>
      *
-     * @param groupId the project ID to add the member to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
      * @param userId the user ID of the member to add, required
      * @param accessLevel the access level for the new member, required
      * @return a Member instance for the added user
      * @throws GitLabApiException if any exception occurs
      */
-    public Member addMember(Integer groupId, Integer userId, AccessLevel accessLevel) throws GitLabApiException {
-        return (addMember(groupId, userId, accessLevel.toValue(), null));
+    public Member addMember(Object groupIdOrPath, Integer userId, AccessLevel accessLevel) throws GitLabApiException {
+        return (addMember(groupIdOrPath, userId, accessLevel.toValue(), null));
     }
 
     /**
      * Adds a user to the list of group members.
      *
-     * POST /groups/:id/members
+     * <pre><code>GitLab Endpoint: POST /groups/:id/members</code></pre>
      *
-     * @param groupId the project ID to add the member to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to add, required
      * @param accessLevel the access level for the new member, required
      * @param expiresAt the date the membership in the group will expire, optional
      * @return a Member instance for the added user
      * @throws GitLabApiException if any exception occurs
      */
-    public Member addMember(Integer groupId, Integer userId, AccessLevel accessLevel, Date expiresAt) throws GitLabApiException {
-        return (addMember(groupId, userId, accessLevel.toValue(), expiresAt));
+    public Member addMember(Object groupIdOrPath, Integer userId, AccessLevel accessLevel, Date expiresAt) throws GitLabApiException {
+        return (addMember(groupIdOrPath, userId, accessLevel.toValue(), expiresAt));
     }
 
     /**
      * Adds a user to the list of group members.
      *
-     * POST /groups/:id/members
+     * <pre><code>GitLab Endpoint: POST /groups/:id/members</code></pre>
      *
-     * @param groupId the project ID to add the member to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to add, required
      * @param accessLevel the access level for the new member, required
      * @param expiresAt the date the membership in the group will expire, optional
      * @return a Member instance for the added user
      * @throws GitLabApiException if any exception occurs
      */
-    public Member addMember(Integer groupId, Integer userId, Integer accessLevel, Date expiresAt) throws GitLabApiException {
+    public Member addMember(Object groupIdOrPath, Integer userId, Integer accessLevel, Date expiresAt) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("user_id", userId, true)
                 .withParam("access_level", accessLevel, true)
                 .withParam("expires_at",  expiresAt, false);
-        Response response = post(Response.Status.CREATED, formData, "groups", groupId, "members");
+        Response response = post(Response.Status.CREATED, formData, "groups", getGroupIdOrPath(groupIdOrPath), "members");
         return (response.readEntity(Member.class));
     }
 
     /**
      * Updates a member of a group.
      *
-     * PUT /groups/:groupId/members/:userId
+     * <pre><code>GitLab Endpoint: PUT /groups/:groupId/members/:userId</code></pre>
      *
-     * @param groupId the group ID the member belongs to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to update, required
      * @param accessLevel the new access level for the member, required
      * @return the updated member
      * @throws GitLabApiException if any exception occurs
      */
-    public Member updateMember(Integer groupId, Integer userId, Integer accessLevel) throws GitLabApiException {
-        return (updateMember(groupId, userId, accessLevel, null));
+    public Member updateMember(Object groupIdOrPath, Integer userId, Integer accessLevel) throws GitLabApiException {
+        return (updateMember(groupIdOrPath, userId, accessLevel, null));
     }
 
     /**
      * Updates a member of a group.
      *
-     * PUT /groups/:groupId/members/:userId
+     * <pre><code>GitLab Endpoint: PUT /groups/:groupId/members/:userId</code></pre>
      *
-     * @param groupId the group ID the member belongs to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to update, required
      * @param accessLevel the new access level for the member, required
      * @return the updated member
      * @throws GitLabApiException if any exception occurs
      */
-    public Member updateMember(Integer groupId, Integer userId, AccessLevel accessLevel) throws GitLabApiException {
-        return (updateMember(groupId, userId, accessLevel.toValue(), null));
+    public Member updateMember(Object groupIdOrPath, Integer userId, AccessLevel accessLevel) throws GitLabApiException {
+        return (updateMember(groupIdOrPath, userId, accessLevel.toValue(), null));
     }
 
     /**
      * Updates a member of a group.
      *
-     * PUT /groups/:groupId/members/:userId
+     * <pre><code>GitLab Endpoint: PUT /groups/:groupId/members/:userId</code></pre>
      *
-     * @param groupId the group ID the member belongs to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to update, required
      * @param accessLevel the new access level for the member, required
      * @param expiresAt the date the membership in the group will expire, optional
      * @return the updated member
      * @throws GitLabApiException if any exception occurs
      */
-    public Member updateMember(Integer groupId, Integer userId, AccessLevel accessLevel, Date expiresAt) throws GitLabApiException {
-        return (updateMember(groupId, userId, accessLevel.toValue(), expiresAt));
+    public Member updateMember(Object groupIdOrPath, Integer userId, AccessLevel accessLevel, Date expiresAt) throws GitLabApiException {
+        return (updateMember(groupIdOrPath, userId, accessLevel.toValue(), expiresAt));
     }
 
     /**
      * Updates a member of a group.
      *
-     * PUT /groups/:groupId/members/:userId
+     * <pre><code>GitLab Endpoint: PUT /groups/:groupId/members/:userId</code></pre>
      *
-     * @param groupId the group ID the member belongs to, required
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to update, required
      * @param accessLevel the new access level for the member, required
      * @param expiresAt the date the membership in the group will expire, optional
      * @return the updated member
      * @throws GitLabApiException if any exception occurs
      */
-    public Member updateMember(Integer groupId, Integer userId, Integer accessLevel, Date expiresAt) throws GitLabApiException {
+    public Member updateMember(Object groupIdOrPath, Integer userId, Integer accessLevel, Date expiresAt) throws GitLabApiException {
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("access_level", accessLevel, true)
                 .withParam("expires_at",  expiresAt, false);
-        Response response = put(Response.Status.OK, formData.asMap(), "groups", groupId, "members", userId);
+        Response response = put(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "members", userId);
         return (response.readEntity(Member.class));
     }
 
     /**
      * Removes member from the group.
      *
-     * DELETE /groups/:id/members/:user_id
+     * <pre><code>GitLab Endpoint: DELETE /groups/:id/members/:user_id</code></pre>
      *
-     * @param groupId the group ID to remove the member from
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @param userId the user ID of the member to remove
      * @throws GitLabApiException if any exception occurs
      */
-    public void removeMember(Integer groupId, Integer userId) throws GitLabApiException {
+    public void removeMember(Object groupIdOrPath, Integer userId) throws GitLabApiException {
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, null, "groups", groupId, "members", userId);
+        delete(expectedStatus, null, "groups", getGroupIdOrPath(groupIdOrPath), "members", userId);
     }
 
     /**

src/main/java/org/gitlab4j/api/IssuesApi.java

@@ -26,6 +26,7 @@ package org.gitlab4j.api;
 import java.util.Date;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.Response;
@@ -48,21 +49,21 @@ public class IssuesApi extends AbstractApi implements Constants {
     }
 
     /**
-     * Get all issues the authenticated user has access to. Only returns issues created by the current user. Only returns the first page
+     * Get all issues the authenticated user has access to. Only returns issues created by the current user.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *
      * @return a list of user's issues
      * @throws GitLabApiException if any exception occurs
      */
     public List<Issue> getIssues() throws GitLabApiException {
-        return (getIssues(1, getDefaultPerPage()));
+        return (getIssues(getDefaultPerPage()).all());
     }
 
     /**
      * Get all issues the authenticated user has access to using the specified page and per page setting. Only returns issues created by the current user.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *
      * @param page the page to get
      * @param perPage the number of issues per page
@@ -77,7 +78,7 @@ public class IssuesApi extends AbstractApi implements Constants {
     /**
      * Get a Pager of all issues the authenticated user has access to. Only returns issues created by the current user.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *r
      * @param itemsPerPage the number of issues per page
      * @return the list of issues in the specified range
@@ -87,69 +88,94 @@ public class IssuesApi extends AbstractApi implements Constants {
         return (new Pager<Issue>(this, Issue.class, itemsPerPage, null, "issues"));
     }
 
+    /**
+     * Get all issues the authenticated user has access to as a Stream. Only returns issues created by the current user.
+     *
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
+     *
+     * @return a Stream of user's issues
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Issue> getIssuesStream() throws GitLabApiException {
+        return (getIssues(getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a list of project's issues. Only returns the first page
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @return a list of project's issues
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Issue> getIssues(Integer projectId) throws GitLabApiException {
-        return (getIssues(projectId, 1, getDefaultPerPage()));
+    public List<Issue> getIssues(Object projectIdOrPath) throws GitLabApiException {
+        return (getIssues(projectIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of project's issues using the specified page and per page settings.
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param page the page to get
      * @param perPage the number of issues per page
      * @return the list of issues in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Issue> getIssues(Integer projectId, int page, int perPage) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "projects", projectId, "issues");
+    public List<Issue> getIssues(Object projectIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "projects", getProjectIdOrPath(projectIdOrPath), "issues");
         return (response.readEntity(new GenericType<List<Issue>>() {}));
     }
 
     /**
      * Get a Pager of project's issues.
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param itemsPerPage the number of issues per page
      * @return the list of issues in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Issue> getIssues(Integer projectId, int itemsPerPage) throws GitLabApiException {
-        return (new Pager<Issue>(this, Issue.class, itemsPerPage, null, "projects", projectId, "issues"));
+    public Pager<Issue> getIssues(Object projectIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Issue>(this, Issue.class, itemsPerPage, null, "projects", getProjectIdOrPath(projectIdOrPath), "issues"));
     }
 
     /**
-     * Get a list of project's issues. Only returns the first page with default 100 items.
+     * Get a Stream of project's issues. Only returns the first page
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectIdOrPath The ID or URL-encoded path of the project owned by the authenticated user.
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @return a Stream of project's issues
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Issue> getIssuesStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getIssues(projectIdOrPath, getDefaultPerPage()).stream());
+    }
+
+    /**
+     * Get a list of project's issues.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings
      * @return the list of issues in the specified range.
      * @throws GitLabApiException if any exception occurs
      */
     public List<Issue> getIssues(Object projectIdOrPath, IssueFilter filter) throws GitLabApiException {
-        return (getIssues(projectIdOrPath, filter, 1, getDefaultPerPage()));
+        return (getIssues(projectIdOrPath, filter, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of project's issues.
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectIdOrPath The ID or URL-encoded path of the project owned by the authenticated user.
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings.
      * @param page the page to get.
      * @param perPage the number of projects per page.
@@ -157,7 +183,6 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Issue> getIssues(Object projectIdOrPath, IssueFilter filter, int page, int perPage) throws GitLabApiException {
-
         GitLabApiForm formData = filter.getQueryParams(page, perPage);
         Response response = get(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "issues");
         return (response.readEntity(new GenericType<List<Issue>>() {}));
@@ -166,40 +191,52 @@ public class IssuesApi extends AbstractApi implements Constants {
     /**
      * Get a list of project's issues.
      *
-     * GET /projects/:id/issues
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
      *
-     * @param projectIdOrPath The ID or URL-encoded path of the project owned by the authenticated user.
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings.
      * @param itemsPerPage the number of Project instances that will be fetched per page.
      * @return the list of issues in the specified range.
      * @throws GitLabApiException if any exception occurs
      */
     public Pager<Issue> getIssues(Object projectIdOrPath, IssueFilter filter, int itemsPerPage) throws GitLabApiException {
-
         GitLabApiForm formData = filter.getQueryParams();
         return (new Pager<Issue>(this, Issue.class, itemsPerPage, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "issues"));
     }
 
+    /**
+     * Get a Stream of project's issues.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings
+     * @return a Stream of issues in the specified range.
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Issue> getIssuesStream(Object projectIdOrPath, IssueFilter filter) throws GitLabApiException {
+        return (getIssues(projectIdOrPath, filter, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get all issues the authenticated user has access to.
      * By default it returns only issues created by the current user.
-     * Only returns the first page with default 100 items.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings
      * @return the list of issues in the specified range.
      * @throws GitLabApiException if any exception occurs
      */
     public List<Issue> getIssues(IssueFilter filter) throws GitLabApiException {
-        return (getIssues(filter, 1, getDefaultPerPage()));
+        return (getIssues(filter, getDefaultPerPage()).all());
     }
 
     /**
      * Get all issues the authenticated user has access to.
      * By default it returns only issues created by the current user.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings.
      * @param page the page to get.
@@ -208,7 +245,6 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Issue> getIssues(IssueFilter filter, int page, int perPage) throws GitLabApiException {
-
         GitLabApiForm formData = filter.getQueryParams(page, perPage);
         Response response = get(Response.Status.OK, formData.asMap(), "issues");
         return (response.readEntity(new GenericType<List<Issue>>() {}));
@@ -218,7 +254,7 @@ public class IssuesApi extends AbstractApi implements Constants {
      * Get all issues the authenticated user has access to.
      * By default it returns only issues created by the current user.
      *
-     * GET /issues
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
      *
      * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings.
      * @param itemsPerPage the number of Project instances that will be fetched per page.
@@ -226,43 +262,51 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @throws GitLabApiException if any exception occurs
      */
     public Pager<Issue> getIssues(IssueFilter filter, int itemsPerPage) throws GitLabApiException {
-
         GitLabApiForm formData = filter.getQueryParams();
         return (new Pager<Issue>(this, Issue.class, itemsPerPage, formData.asMap(),  "issues"));
     }
 
+    /**
+     * Get all issues the authenticated user has access to.
+     * By default it returns only issues created by the current user.
+     *
+     * <pre><code>GitLab Endpoint: GET /issues</code></pre>
+     *
+     * @param filter {@link IssueFilter} a IssueFilter instance with the filter settings
+     * @return the list of issues in the specified range.
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Issue> getIssuesStream(IssueFilter filter) throws GitLabApiException {
+        return (getIssues(filter, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a single project issue.
      *
-     * GET /projects/:id/issues/:issue_iid
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid</code></pre>
      *
-     * @param projectId the project ID to get the issue for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueId the internal ID of a project's issue
      * @return the specified Issue instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Issue getIssue(Integer projectId, Integer issueId) throws GitLabApiException {
-        
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
-
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "projects", projectId, "issues", issueId);
+    public Issue getIssue(Object projectIdOrPath, Integer issueId) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueId);
         return (response.readEntity(Issue.class));
     }
 
     /**
      * Get a single project issue as an Optional instance.
      *
-     * GET /projects/:id/issues/:issue_iid
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid</code></pre>
      *
-     * @param projectId the project ID to get the issue for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueId the internal ID of a project's issue
      * @return the specified Issue as an Optional instance
      */
-    public Optional<Issue> getOptionalIssue(Integer projectId, Integer issueId) {
+    public Optional<Issue> getOptionalIssue(Object projectIdOrPath, Integer issueId) {
         try {
-            return (Optional.ofNullable(getIssue(projectId, issueId)));
+            return (Optional.ofNullable(getIssue(projectIdOrPath, issueId)));
         } catch (GitLabApiException glae) {
             return (GitLabApi.createOptionalFromException(glae));
         }
@@ -271,24 +315,24 @@ public class IssuesApi extends AbstractApi implements Constants {
     /**
      * Create an issue for the project.
      *
-     * POST /projects/:id/issues
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues</code></pre>
      * 
-     * @param projectId the ID of the project owned by the authenticated user, required
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param title the title of an issue, required
      * @param description the description of an issue, optional
      * @return an instance of Issue
      * @throws GitLabApiException if any exception occurs
      */
-    public Issue createIssue(Integer projectId, String title, String description) throws GitLabApiException {
-        return (createIssue(projectId, title, description, null, null, null, null, null, null, null, null));
+    public Issue createIssue(Object projectIdOrPath, String title, String description) throws GitLabApiException {
+        return (createIssue(projectIdOrPath, title, description, null, null, null, null, null, null, null, null));
     }
 
     /**
      * Create an issue for the project.
      *
-     * POST /projects/:id/issues
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues</code></pre>
      *
-     * @param projectId the ID of the project owned by the authenticated user, required
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param title the issue title of an issue, required
      * @param description the description of an issue, optional
      * @param confidential set the issue to be confidential, default is false, optional
@@ -304,13 +348,9 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @return an instance of Issue
      * @throws GitLabApiException if any exception occurs
      */
-    public Issue createIssue(Integer projectId, String title, String description, Boolean confidential, List<Integer> assigneeIds, Integer milestoneId, String labels,
+    public Issue createIssue(Object projectIdOrPath, String title, String description, Boolean confidential, List<Integer> assigneeIds, Integer milestoneId, String labels,
             Date createdAt, Date dueDate, Integer mergeRequestToResolveId, Integer discussionToResolveId) throws GitLabApiException {
 
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
-
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("title", title, true)
                 .withParam("description", description)
@@ -322,41 +362,37 @@ public class IssuesApi extends AbstractApi implements Constants {
                 .withParam("due_date", dueDate)
                 .withParam("merge_request_to_resolve_discussions_of", mergeRequestToResolveId)
                 .withParam("discussion_to_resolve", discussionToResolveId);
-        Response response = post(Response.Status.CREATED, formData, "projects", projectId, "issues");
+        Response response = post(Response.Status.CREATED, formData, "projects", getProjectIdOrPath(projectIdOrPath), "issues");
         return (response.readEntity(Issue.class));        
     }
 
     /**
      * Closes an existing project issue.
      *
-     * PUT /projects/:id/issues/:issue_iid
+     * <pre><code>GitLab Endpoint: PUT /projects/:id/issues/:issue_iid</code></pre>
      *
-     * @param projectId the ID of the project owned by the authenticated user, required
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueIid the issue IID to update, required
      * @return an instance of the updated Issue
      * @throws GitLabApiException if any exception occurs
      */
-    public Issue closeIssue(Integer projectId, Integer issueIid) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("project ID cannot be null");
-        }
+    public Issue closeIssue(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
 
         GitLabApiForm formData = new GitLabApiForm().withParam("state_event", StateEvent.CLOSE);          
-        Response response = put(Response.Status.OK, formData.asMap(), "projects", projectId, "issues", issueIid);
+        Response response = put(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid);
         return (response.readEntity(Issue.class));        
     }
 
     /**
      * Updates an existing project issue. This call can also be used to mark an issue as closed.
      *
-     * PUT /projects/:id/issues/:issue_iid
+     * <pre><code>GitLab Endpoint: PUT /projects/:id/issues/:issue_iid</code></pre>
      *
-     * @param projectId the ID of the project owned by the authenticated user, required
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueIid the issue IID to update, required
      * @param title the title of an issue, optional
      * @param description the description of an issue, optional
@@ -370,13 +406,9 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @return an instance of the updated Issue
      * @throws GitLabApiException if any exception occurs
      */
-    public Issue updateIssue(Integer projectId, Integer issueIid, String title, String description, Boolean confidential, List<Integer> assigneeIds, 
+    public Issue updateIssue(Object projectIdOrPath, Integer issueIid, String title, String description, Boolean confidential, List<Integer> assigneeIds, 
             Integer milestoneId, String labels, StateEvent stateEvent, Date updatedAt, Date dueDate) throws GitLabApiException {
 
-        if (projectId == null) {
-            throw new RuntimeException("project ID cannot be null");
-        }
-
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
@@ -391,79 +423,71 @@ public class IssuesApi extends AbstractApi implements Constants {
                 .withParam("state_event", stateEvent)
                 .withParam("updated_at", updatedAt)
                 .withParam("due_date", dueDate);
-        Response response = put(Response.Status.OK, formData.asMap(), "projects", projectId, "issues", issueIid);
+        Response response = put(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid);
         return (response.readEntity(Issue.class));        
     }
 
     /**
      * Delete an issue.
      *
-     * DELETE /projects/:id/issues/:issue_iid
+     * <pre><code>GitLab Endpoint: DELETE /projects/:id/issues/:issue_iid</code></pre>
      *
-     * @param projectId the project ID to delete the issue from
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueIid the internal ID of a project's issue
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteIssue(Integer projectId, Integer issueIid) throws GitLabApiException {
-        
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public void deleteIssue(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
 
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, getDefaultPerPageParam(), "projects", projectId, "issues", issueIid);
+        delete(expectedStatus, getDefaultPerPageParam(), "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid);
     }
 
     /**
      * Sets an estimated time of work in this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/time_estimate
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/time_estimate</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueIid the internal ID of a project's issue
      * @param duration estimated time in seconds
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats estimateTime(Integer projectId, Integer issueIid, int duration) throws GitLabApiException {
-        return (estimateTime(projectId, issueIid, new Duration(duration)));
+    public TimeStats estimateTime(Object projectIdOrPath, Integer issueIid, int duration) throws GitLabApiException {
+        return (estimateTime(projectIdOrPath, issueIid, new Duration(duration)));
     }
 
     /**
      * Sets an estimated time of work in this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/time_estimate
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/time_estimate</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueIid the internal ID of a project's issue
      * @param duration Human readable format, e.g. 3h30m
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats estimateTime(Integer projectId, Integer issueIid, String duration) throws GitLabApiException {
-        return (estimateTime(projectId, issueIid, new Duration(duration)));
+    public TimeStats estimateTime(Object projectIdOrPath, Integer issueIid, String duration) throws GitLabApiException {
+        return (estimateTime(projectIdOrPath, issueIid, new Duration(duration)));
     }
 
     /**
      * Sets an estimated time of work in this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/time_estimate
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/time_estimate</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @param duration set the estimate of time to this duration
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats estimateTime(Integer projectId, Integer issueIid, Duration duration) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public TimeStats estimateTime(Object projectIdOrPath, Integer issueIid, Duration duration) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
@@ -472,80 +496,74 @@ public class IssuesApi extends AbstractApi implements Constants {
         String durationString = (duration != null ? DurationUtils.toString(duration.getSeconds(), false) : null);
         GitLabApiForm formData = new GitLabApiForm().withParam("duration", durationString, true);
 
-        Response response = post(Response.Status.OK, formData.asMap(), "projects", projectId, "issues", issueIid, "time_estimate");
+        Response response = post(Response.Status.OK, formData.asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "time_estimate");
         return (response.readEntity(TimeStats.class));
     }
 
     /**
      * Resets the estimated time for this issue to 0 seconds.
      * 
-     * POST /projects/:id/issues/:issue_iid/reset_time_estimate
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/reset_time_estimate</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats resetEstimatedTime(Integer projectId, Integer issueIid) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public TimeStats resetEstimatedTime(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
 
-        Response response = post(Response.Status.OK, new GitLabApiForm().asMap(), "projects", projectId, "issues", issueIid, "reset_time_estimate");
+        Response response = post(Response.Status.OK, new GitLabApiForm().asMap(), "projects",
+                getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "reset_time_estimate");
         return (response.readEntity(TimeStats.class));
     }
 
     /**
      * Adds spent time for this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/add_spent_time
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/add_spent_time</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @param duration the duration in seconds
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats addSpentTime(Integer projectId, Integer issueIid, int duration) throws GitLabApiException {
-        return (addSpentTime(projectId, issueIid, new Duration(duration)));
+    public TimeStats addSpentTime(Object projectIdOrPath, Integer issueIid, int duration) throws GitLabApiException {
+        return (addSpentTime(projectIdOrPath, issueIid, new Duration(duration)));
     }
 
     /**
      * Adds spent time for this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/add_spent_time
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/add_spent_time</code></pre>
      * 
-     * @param projectId the project ID to delete the issue from
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @param duration Human readable format, e.g. 3h30m
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats addSpentTime(Integer projectId, Integer issueIid, String duration) throws GitLabApiException {
-        return (addSpentTime(projectId, issueIid, new Duration(duration)));
+    public TimeStats addSpentTime(Object projectIdOrPath, Integer issueIid, String duration) throws GitLabApiException {
+        return (addSpentTime(projectIdOrPath, issueIid, new Duration(duration)));
     }
 
     /**
      * Adds spent time for this issue
      * 
-     * POST /projects/:id/issues/:issue_iid/add_spent_time
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/add_spent_time</code></pre>
      * 
-     * @param projectId the project ID to delete the issue from
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @param duration the duration of time spent
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats addSpentTime(Integer projectId, Integer issueIid, Duration duration) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public TimeStats addSpentTime(Object projectIdOrPath, Integer issueIid, Duration duration) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
@@ -554,70 +572,65 @@ public class IssuesApi extends AbstractApi implements Constants {
         String durationString = (duration != null ? DurationUtils.toString(duration.getSeconds(), false) : null);
         GitLabApiForm formData = new GitLabApiForm().withParam("duration", durationString, true);
 
-        Response response = post(Response.Status.CREATED, formData.asMap(), "projects", projectId, "issues", issueIid, "add_spent_time");
+        Response response = post(Response.Status.CREATED, formData.asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "add_spent_time");
         return (response.readEntity(TimeStats.class));
     }
 
     /**
      * Resets the total spent time for this issue to 0 seconds.
      * 
-     * POST /projects/:id/issues/:issue_iid/reset_spent_time
+     * <pre><code>GitLab Endpoint: POST /projects/:id/issues/:issue_iid/reset_spent_time</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @return a TimeSTats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats resetSpentTime(Integer projectId, Integer issueIid) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public TimeStats resetSpentTime(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
 
-        Response response = post(Response.Status.OK, new GitLabApiForm().asMap(), "projects", projectId, "issues", issueIid, "reset_spent_time");
+        Response response = post(Response.Status.OK, new GitLabApiForm().asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "reset_spent_time");
         return (response.readEntity(TimeStats.class));
     }
 
     /**
      * Get time tracking stats.
      * 
-     * GET /projects/:id/issues/:issue_iid/time_stats
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/time_stats</code></pre>
      * 
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @return a TimeStats instance
      * @throws GitLabApiException if any exception occurs
      */
-    public TimeStats getTimeTrackingStats(Integer projectId, Integer issueIid) throws GitLabApiException {
-
-       if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public TimeStats getTimeTrackingStats(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issue IID cannot be null");
         }
 
-        Response response = get(Response.Status.OK, new GitLabApiForm().asMap(), "projects", projectId, "issues", issueIid, "time_stats");
+        Response response = get(Response.Status.OK, new GitLabApiForm().asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "time_stats");
         return (response.readEntity(TimeStats.class));
     }
 
     /**
      * Get time tracking stats as an Optional instance
      *
-     * GET /projects/:id/issues/:issue_iid/time_stats
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/time_stats</code></pre>
      *
-     * @param projectId the project ID that owns the issue
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the internal ID of a project's issue
      * @return a TimeStats as an Optional instance
      */
-    public Optional<TimeStats> getOptionalTimeTrackingStats(Integer projectId, Integer issueIid) {
+    public Optional<TimeStats> getOptionalTimeTrackingStats(Object projectIdOrPath, Integer issueIid) {
         try {
-            return (Optional.ofNullable(getTimeTrackingStats(projectId, issueIid)));
+            return (Optional.ofNullable(getTimeTrackingStats(projectIdOrPath, issueIid)));
         } catch (GitLabApiException glae) {
             return (GitLabApi.createOptionalFromException(glae));
         }
@@ -626,7 +639,7 @@ public class IssuesApi extends AbstractApi implements Constants {
     /**
      * Get list containing all the merge requests that will close issue when merged.
      *
-     * GET /projects/:id/issues/:issue_iid/closed_by
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/closed_by</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param issueIid the internal ID of a project's issue
@@ -634,13 +647,13 @@ public class IssuesApi extends AbstractApi implements Constants {
      * @throws GitLabApiException if any exception occurs
      */
     public List<MergeRequest> getClosedByMergeRequests(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
-        return (getClosedByMergeRequests(projectIdOrPath, issueIid, 1, getDefaultPerPage()));
+        return (getClosedByMergeRequests(projectIdOrPath, issueIid, getDefaultPerPage()).all());
     }
 
     /**
      * Get list containing all the merge requests that will close issue when merged.
      *
-     * GET /projects/:id/issues/:issue_iid/closed_by
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/closed_by</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param issueIid the internal ID of a project's issue
@@ -658,7 +671,7 @@ public class IssuesApi extends AbstractApi implements Constants {
     /**
      * Get a Pager containing all the merge requests that will close issue when merged.
      *
-     * GET /projects/:id/issues/:issue_iid/closed_by
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/closed_by</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param issueIid the internal ID of a project's issue
@@ -670,4 +683,18 @@ public class IssuesApi extends AbstractApi implements Constants {
         return new Pager<MergeRequest>(this, MergeRequest.class, itemsPerPage, null,
                 "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "closed_by");
     }
+
+    /**
+     * Get list containing all the merge requests that will close issue when merged.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/closed_by</code></pre>
+     *
+     * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
+     * @param issueIid the internal ID of a project's issue
+     * @return a List containing all the merge requests what will close the issue when merged.
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<MergeRequest> getClosedByMergeRequestsStream(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
+        return (getClosedByMergeRequests(projectIdOrPath, issueIid, getDefaultPerPage()).stream());
+    }
 }

src/main/java/org/gitlab4j/api/NotesApi.java

@@ -2,6 +2,7 @@ package org.gitlab4j.api;
 
 import java.util.Date;
 import java.util.List;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.Response;
@@ -15,184 +16,192 @@ public class NotesApi extends AbstractApi {
     }
 
     /**
-     * Get a list of the issues's notes. Only returns the first page
+     * Get a list of the issues's notes.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue ID to get the notes for
      * @return a list of the issues's notes
      * @throws GitLabApiException if any exception occurs
-     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Integer, Integer)}
+     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Object, Integer)}
      */
-    public List<Note> getNotes(Integer projectId, Integer issueIid) throws GitLabApiException {
-        return (getIssueNotes(projectId, issueIid));
+    @Deprecated
+    public List<Note> getNotes(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
+        return (getIssueNotes(projectIdOrPath, issueIid));
     }
 
     /**
      * Get a list of the issue's notes using the specified page and per page settings.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to get the notes for
      * @param page the page to get
      * @param perPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
-     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Integer, Integer, int, int)}
+     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Object, Integer, int, int)}
      */
-    public List<Note> getNotes(Integer projectId, Integer issueIid, int page, int perPage) throws GitLabApiException {
-        return (getIssueNotes(projectId, issueIid, page, perPage));
+    @Deprecated
+    public List<Note> getNotes(Object projectIdOrPath, Integer issueIid, int page, int perPage) throws GitLabApiException {
+        return (getIssueNotes(projectIdOrPath, issueIid, page, perPage));
     }
 
     /**
      * Get a Pager of issues's notes.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to get the notes for
      * @param itemsPerPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
-     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Integer, Integer, int)}
+     * @deprecated As of release 4.7.0, replaced by {@link #getIssueNotes(Object, Integer, int)}
      */
-    public Pager<Note> getNotes(Integer projectId, Integer issueIid, int itemsPerPage) throws GitLabApiException {
-        return (getIssueNotes(projectId, issueIid, itemsPerPage));
+    @Deprecated
+    public Pager<Note> getNotes(Object projectIdOrPath, Integer issueIid, int itemsPerPage) throws GitLabApiException {
+        return (getIssueNotes(projectIdOrPath, issueIid, itemsPerPage));
     }
 
     /**
-     * Get a list of the issues's notes. Only returns the first page
+     * Get a list of the issues's notes.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue ID to get the notes for
      * @return a list of the issues's notes
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getIssueNotes(Integer projectId, Integer issueIid) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "projects", projectId, "issues", issueIid, "notes");
-        return (response.readEntity(new GenericType<List<Note>>() {}));
+    public List<Note> getIssueNotes(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
+        return (getIssueNotes(projectIdOrPath, issueIid, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of the issue's notes using the specified page and per page settings.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to get the notes for
      * @param page the page to get
      * @param perPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getIssueNotes(Integer projectId, Integer issueIid, int page, int perPage) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "projects", projectId, "issues", issueIid, "notes");
+    public List<Note> getIssueNotes(Object projectIdOrPath, Integer issueIid, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage),"projects",
+                getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes");
         return (response.readEntity(new GenericType<List<Note>>() {}));
     }
 
     /**
      * Get a Pager of issues's notes.
      *
-     * GET /projects/:id/issues/:issue_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to get the notes for
      * @param itemsPerPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Note> getIssueNotes(Integer projectId, Integer issueIid, int itemsPerPage) throws GitLabApiException {
-        return (new Pager<Note>(this, Note.class, itemsPerPage, null, "projects", projectId, "issues", issueIid, "notes"));
+    public Pager<Note> getIssueNotes(Object projectIdOrPath, Integer issueIid, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Note>(this, Note.class, itemsPerPage, null,
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes"));
+    }
+
+    /**
+     * Get a Stream of the issues's notes.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/issues/:issue_iid/notes</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param issueIid the issue ID to get the notes for
+     * @return a Stream of the issues's notes
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Note> getIssueNotesStream(Object projectIdOrPath, Integer issueIid) throws GitLabApiException {
+        return (getIssueNotes(projectIdOrPath, issueIid, getDefaultPerPage()).stream());
     }
 
     /**
      * Get the specified issues's note.
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to get the notes for
      * @param noteId the ID of the Note to get
      * @return a Note instance for the specified IDs
      * @throws GitLabApiException if any exception occurs
      */
-    public Note getIssueNote(Integer projectId, Integer issueIid, Integer noteId) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(), "projects", projectId, "issues", issueIid, "notes", noteId);
+    public Note getIssueNote(Object projectIdOrPath, Integer issueIid, Integer noteId) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getDefaultPerPageParam(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes", noteId);
         return (response.readEntity(Note.class));
     }
 
     /**
      * Create a issues's note.
-     *
-     * @param projectId the project ID to create the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance @param projectIdOrPath the project ID to create the issues for
      * @param issueIid the issue IID to create the notes for
      * @param body the content of note
      * @return the created Note instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Note createIssueNote(Integer projectId, Integer issueIid, String body) throws GitLabApiException {
-        return (createIssueNote(projectId, issueIid, body, null));
+    public Note createIssueNote(Object projectIdOrPath, Integer issueIid, String body) throws GitLabApiException {
+        return (createIssueNote(projectIdOrPath, issueIid, body, null));
     }
 
     /**
      * Create a issues's note.
      *
-     * @param projectId the project ID to create the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to create the notes for
      * @param body the content of note
      * @param createdAt the created time of note
      * @return the created Note instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Note createIssueNote(Integer projectId, Integer issueIid, String body, Date createdAt) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public Note createIssueNote(Object projectIdOrPath, Integer issueIid, String body, Date createdAt) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("body", body, true)
                 .withParam("created_at", createdAt);
-        Response response = post(Response.Status.CREATED, formData, "projects", projectId, "issues", issueIid, "notes");
+        Response response = post(Response.Status.CREATED, formData,
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes");
         return (response.readEntity(Note.class));
     }
 
     /**
      * Update the specified issues's note.
      *
-     * @param projectId the project ID to update the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to update the notes for
      * @param noteId the ID of the node to update
      * @param body the update content for the Note
      * @return the modified Note instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Note updateIssueNote(Integer projectId, Integer issueIid, Integer noteId, String body) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public Note updateIssueNote(Object projectIdOrPath, Integer issueIid, Integer noteId, String body) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm().withParam("body", body, true);
-        Response response = put(Response.Status.OK, formData.asMap(), "projects", projectId, "issues", issueIid, "notes", noteId);
+        Response response = put(Response.Status.OK, formData.asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes", noteId);
         return (response.readEntity(Note.class));
     }
 
     /**
      * Delete the specified issues's note.
      *
-     * @param projectId the project ID to delete the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param issueIid the issue IID to delete the notes for
      * @param noteId the ID of the node to delete
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteIssueNote(Integer projectId, Integer issueIid, Integer noteId) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public void deleteIssueNote(Object projectIdOrPath, Integer issueIid, Integer noteId) throws GitLabApiException {
 
         if (issueIid == null) {
             throw new RuntimeException("issueIid cannot be null");
@@ -203,61 +212,62 @@ public class NotesApi extends AbstractApi {
         }
 
         Response.Status expectedStatus = (isApiVersion(GitLabApi.ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, getDefaultPerPageParam(), "projects", projectId, "issues", issueIid, "notes", noteId);
+        delete(expectedStatus, getDefaultPerPageParam(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "issues", issueIid, "notes", noteId);
     }
 
     /**
-     * Gets a list of all notes for a single merge request. Only returns the first page
+     * Gets a list of all notes for a single merge request
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the issue ID to get the notes for
      * @return a list of the merge request's notes
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid) throws GitLabApiException {
-        return (getMergeRequestNotes(projectId, mergeRequestIid, null, null, 1, getDefaultPerPage()));
+    public List<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, null, null, getDefaultPerPage()).all());
     }
 
     /**
-     * Gets a list of all notes for a single merge request. Only returns the first page
+     * Gets a list of all notes for a single merge request.
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the issue ID to get the notes for
      * @param sortOrder return merge request notes sorted in the specified sort order, default is DESC
      * @param orderBy return merge request notes ordered by CREATED_AT or UPDATED_AT, default is CREATED_AT
      * @return a list of the merge request's notes
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid, SortOrder sortOrder, Note.OrderBy orderBy) throws GitLabApiException {
-        return (getMergeRequestNotes(projectId, mergeRequestIid, sortOrder, orderBy, 1, getDefaultPerPage()));
+    public List<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid, SortOrder sortOrder, Note.OrderBy orderBy) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, sortOrder, orderBy, getDefaultPerPage()).all());
     }
 
     /**
      * Gets a list of all notes for a single merge request using the specified page and per page settings.
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the merge request IID to get the notes for
      * @param page the page to get
      * @param perPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid, int page, int perPage) throws GitLabApiException {
-        return (getMergeRequestNotes(projectId, mergeRequestIid, null, null, page, perPage));
+    public List<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid, int page, int perPage) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, null, null, page, perPage));
     }
 
     /**
      * Gets a list of all notes for a single merge request using the specified page and per page settings.
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the merge request IID to get the notes for
      * @param sortOrder return merge request notes sorted in the specified sort order, default is DESC
      * @param orderBy return merge request notes ordered by CREATED_AT or UPDATED_AT, default is CREATED_AT
@@ -266,7 +276,7 @@ public class NotesApi extends AbstractApi {
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public List<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid,
+    public List<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid,
             SortOrder sortOrder, Note.OrderBy orderBy, int page, int perPage) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm()
@@ -274,31 +284,46 @@ public class NotesApi extends AbstractApi {
                 .withParam("order_by", orderBy)
                 .withParam(PAGE_PARAM, page)
                 .withParam(PER_PAGE_PARAM, perPage);
-        Response response = get(Response.Status.OK, formData.asMap(), "projects", projectId, "merge_requests", mergeRequestIid, "notes");
+        Response response = get(Response.Status.OK, formData.asMap(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes");
         return (response.readEntity(new GenericType<List<Note>>() {}));
     }
 
     /**
      * Get a Pager of all notes for a single merge request
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the merge request IID to get the notes for
      * @param itemsPerPage the number of notes per page
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid, int itemsPerPage) throws GitLabApiException {
-        return (getMergeRequestNotes(projectId, mergeRequestIid, null, null, itemsPerPage));
+    public Pager<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid, int itemsPerPage) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, null, null, itemsPerPage));
+    }
+
+    /**
+     * Gets a Stream of all notes for a single merge request
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param mergeRequestIid the issue ID to get the notes for
+     * @return a Stream of the merge request's notes
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Note> getMergeRequestNotesStream(Object projectIdOrPath, Integer mergeRequestIid) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, null, null, getDefaultPerPage()).stream());
     }
 
     /**
      * Get a Pager of all notes for a single merge request
      *
-     * GET /projects/:id/merge_requests/:merge_request_iid/notes
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the merge request IID to get the notes for
      * @param sortOrder return merge request notes sorted in the specified sort order, default is DESC
      * @param orderBy return merge request notes ordered by CREATED_AT or UPDATED_AT, default is CREATED_AT
@@ -306,7 +331,7 @@ public class NotesApi extends AbstractApi {
      * @return the list of notes in the specified range
      * @throws GitLabApiException if any exception occurs
      */
-    public Pager<Note> getMergeRequestNotes(Integer projectId, Integer mergeRequestIid,
+    public Pager<Note> getMergeRequestNotes(Object projectIdOrPath, Integer mergeRequestIid,
             SortOrder sortOrder, Note.OrderBy orderBy, int itemsPerPage) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm()
@@ -315,80 +340,83 @@ public class NotesApi extends AbstractApi {
                 .withParam(PAGE_PARAM, 1)
                 .withParam(PER_PAGE_PARAM, itemsPerPage);
         return (new Pager<Note>(this, Note.class, itemsPerPage, formData.asMap(),
-                "projects", projectId, "merge_requests", mergeRequestIid, "notes"));
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes"));
+    }
+
+    /**
+     * Gets a Stream of all notes for a single merge request.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/merge_requests/:merge_request_iid/notes</code></pre>
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param mergeRequestIid the issue ID to get the notes for
+     * @param sortOrder return merge request notes sorted in the specified sort order, default is DESC
+     * @param orderBy return merge request notes ordered by CREATED_AT or UPDATED_AT, default is CREATED_AT
+     * @return a Stream of the merge request's notes
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Note> getMergeRequestNotesStream(Object projectIdOrPath, Integer mergeRequestIid, SortOrder sortOrder, Note.OrderBy orderBy) throws GitLabApiException {
+        return (getMergeRequestNotes(projectIdOrPath, mergeRequestIid, sortOrder, orderBy, getDefaultPerPage()).stream());
     }
 
     /**
      * Get the specified merge request's note.
      *
-     * @param projectId the project ID to get the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid  the merge request IID to get the notes for
      * @param noteId the ID of the Note to get
      * @return a Note instance for the specified IDs
      * @throws GitLabApiException if any exception occurs
      */
-    public Note getMergeRequestNote(Integer projectId, Integer mergeRequestIid, Integer noteId) throws GitLabApiException {
+    public Note getMergeRequestNote(Object projectIdOrPath, Integer mergeRequestIid, Integer noteId) throws GitLabApiException {
         Response response = get(Response.Status.OK, getDefaultPerPageParam(),
-                "projects", projectId, "merge_requests", mergeRequestIid, "notes", noteId);
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes", noteId);
         return (response.readEntity(Note.class));
     }
 
     /**
      * Create a merge request's note.
      *
-     * @param projectId the project ID to create the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid  the merge request IID to create the notes for
      * @param body the content of note
      * @return the created Note instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Note createMergeRequestNote(Integer projectId, Integer mergeRequestIid, String body) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
-
+    public Note createMergeRequestNote(Object projectIdOrPath, Integer mergeRequestIid, String body) throws GitLabApiException {
         GitLabApiForm formData = new GitLabApiForm().withParam("body", body, true);
         Response response = post(Response.Status.CREATED, formData,
-                "projects", projectId, "merge_requests", mergeRequestIid, "notes");
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes");
         return (response.readEntity(Note.class));
     }
 
     /**
      * Update the specified merge request's note.
      *
-     * @param projectId the project ID to update the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid  the merge request IID to update the notes for
      * @param noteId the ID of the node to update
      * @param body the update content for the Note
      * @return the modified Note instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Note updateMergeRequestNote(Integer projectId, Integer mergeRequestIid, Integer noteId, String body) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public Note updateMergeRequestNote(Object projectIdOrPath, Integer mergeRequestIid, Integer noteId, String body) throws GitLabApiException {
 
         GitLabApiForm formData = new GitLabApiForm().withParam("body", body, true);
         Response response = put(Response.Status.OK, formData.asMap(),
-                "projects", projectId, "merge_requests", mergeRequestIid, "notes", noteId);
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes", noteId);
         return (response.readEntity(Note.class));
     }
 
     /**
      * Delete the specified merge request's note.
      *
-     * @param projectId the project ID to delete the issues for
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
      * @param mergeRequestIid the merge request IID to delete the notes for
      * @param noteId the ID of the node to delete
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteMergeRequestNote(Integer projectId, Integer mergeRequestIid, Integer noteId) throws GitLabApiException {
-
-        if (projectId == null) {
-            throw new RuntimeException("projectId cannot be null");
-        }
+    public void deleteMergeRequestNote(Object projectIdOrPath, Integer mergeRequestIid, Integer noteId) throws GitLabApiException {
 
         if (mergeRequestIid == null) {
             throw new RuntimeException("mergeRequestIid cannot be null");
@@ -399,6 +427,7 @@ public class NotesApi extends AbstractApi {
         }
 
         Response.Status expectedStatus = (isApiVersion(GitLabApi.ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, getDefaultPerPageParam(), "projects", projectId, "merge_requests", mergeRequestIid, "notes", noteId);
+        delete(expectedStatus, getDefaultPerPageParam(),
+                "projects", getProjectIdOrPath(projectIdOrPath), "merge_requests", mergeRequestIid, "notes", noteId);
     }
 }

src/main/java/org/gitlab4j/api/ProjectApi.java

@@ -1794,7 +1794,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @return a list of project's issues
      * @throws GitLabApiException if any exception occurs
-     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Integer)}
+     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Object)}
      */
     @Deprecated
     public List<Issue> getIssues(Object projectIdOrPath) throws GitLabApiException {
@@ -1811,7 +1811,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param perPage the number of issues per page
      * @return the list of issues in the specified range
      * @throws GitLabApiException if any exception occurs
-     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Integer, int, int)}
+     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Object, int, int)}
      */
     @Deprecated
     public List<Issue> getIssues(Object projectIdOrPath, int page, int perPage) throws GitLabApiException {
@@ -1828,7 +1828,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param itemsPerPage the number of issues per page
      * @return the list of issues in the specified range
      * @throws GitLabApiException if any exception occurs
-     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Integer, int)}
+     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Object, int)}
      */
     @Deprecated
     public Pager<Issue> getIssues(Object projectIdOrPath, int itemsPerPage) throws GitLabApiException {
@@ -1843,7 +1843,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @return a Stream of the project's issues
      * @throws GitLabApiException if any exception occurs
-     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Integer)}
+     * @deprecated Will be removed in version 5.0, replaced by {@link IssuesApi#getIssues(Object)}
      */
     @Deprecated
     public Stream<Issue> getIssuesStream(Object projectIdOrPath) throws GitLabApiException {
@@ -1859,7 +1859,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param issueId the internal ID of a project's issue
      * @return the specified Issue instance
      * @throws GitLabApiException if any exception occurs
-     * @deprecated  Will be removed in version 5.0, replaced by {@link IssuesApi#getIssue(Integer, Integer)}
+     * @deprecated  Will be removed in version 5.0, replaced by {@link IssuesApi#getIssue(Object, Integer)}
      */
     @Deprecated
     public Issue getIssue(Object projectIdOrPath, Integer issueId) throws GitLabApiException {
@@ -1875,7 +1875,7 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
      * @param issueId the internal ID of a project's issue
      * @throws GitLabApiException if any exception occurs
-     * @deprecated  Will be removed in version 5.0, replaced by {@link IssuesApi#deleteIssue(Integer, Integer)}
+     * @deprecated  Will be removed in version 5.0, replaced by {@link IssuesApi#deleteIssue(Object, Integer)}
      */
     @Deprecated
     public void deleteIssue(Object projectIdOrPath, Integer issueId) throws GitLabApiException {
@@ -2398,8 +2398,8 @@ public class ProjectApi extends AbstractApi implements Constants {
      * @return the updated Project instance
      * @throws GitLabApiException if any exception occurs
      */
-    public Project setProjectAvatar(Object projectIdOrPath, File fileToUpload) throws GitLabApiException {
-        return (setProjectAvatar(projectIdOrPath, fileToUpload, null));
+    public Project setProjectAvatar(Object projectIdOrPath, File avatarFile) throws GitLabApiException {
+        return (setProjectAvatar(projectIdOrPath, avatarFile, null));
     }
 
     /**

src/main/java/org/gitlab4j/api/RepositoryApi.java

@@ -7,6 +7,7 @@ import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -40,9 +41,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Branch> getBranches(Object projectIdOrPath) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(),
-                "projects", getProjectIdOrPath(projectIdOrPath), "repository", "branches");
-        return (response.readEntity(new GenericType<List<Branch>>() {}));
+        return (getBranches(projectIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
@@ -78,6 +77,19 @@ public class RepositoryApi extends AbstractApi {
                 getProjectIdOrPath(projectIdOrPath), "repository", "branches"));
     }
 
+    /**
+     * Get a Stream of repository branches from a project, sorted by name alphabetically.
+     *
+     * GET /projects/:id/repository/branches
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @return a Stream of repository branches for the specified project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Branch> getBranchesStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getBranches(projectIdOrPath, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a single project repository branch.
      *
@@ -192,6 +204,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @deprecated Replaced by TagsApi.getTags(Object)
      */
+    @Deprecated
     public List<Tag> getTags(Object projectIdOrPath) throws GitLabApiException {
         Response response = get(Response.Status.OK, getDefaultPerPageParam(), "projects",
                 getProjectIdOrPath(projectIdOrPath), "repository", "tags");
@@ -210,6 +223,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @deprecated Replaced by TagsApi.getTags(Object, int, int)
      */
+    @Deprecated
     public List<Tag> getTags(Object projectIdOrPath, int page, int perPage) throws GitLabApiException {
         Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "projects",
                 getProjectIdOrPath(projectIdOrPath), "repository", "tags");
@@ -227,6 +241,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @deprecated Replaced by TagsApi.getTags(Object, int)
      */
+    @Deprecated
     public Pager<Tag> getTags(Object projectIdOrPath, int itemsPerPage) throws GitLabApiException {
         return (new Pager<Tag>(this, Tag.class, itemsPerPage, null, "projects",
                 getProjectIdOrPath(projectIdOrPath), "repository", "tags"));
@@ -332,6 +347,19 @@ public class RepositoryApi extends AbstractApi {
         return (getTree(projectIdOrPath, "/", "master", false, itemsPerPage));
     }
 
+    /**
+     * Get a list of repository files and directories in a project.
+     *
+     * GET /projects/:id/repository/tree
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @return a Stream containing a tree with the root directories and files of a project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<TreeItem> getTreeStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getTreeStream(projectIdOrPath, "/", "master"));
+    }
+
     /**
      * Get a list of repository files and directories in a project.
      *
@@ -371,6 +399,25 @@ public class RepositoryApi extends AbstractApi {
         return (getTree(projectIdOrPath, filePath, refName, false, itemsPerPage));
     }
 
+    /**
+     * Get a Stream of repository files and directories in a project.
+     *
+     * GET /projects/:id/repository/tree
+     *
+     * id (required) - The ID of a project
+     * path (optional) - The path inside repository. Used to get content of subdirectories
+     * ref_name (optional) - The name of a repository branch or tag or if not given the default branch
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param filePath the path inside repository, used to get content of subdirectories
+     * @param refName the name of a repository branch or tag or if not given the default branch
+     * @return a Stream containing a tree with the directories and files of a project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<TreeItem> getTreeStream(Object projectIdOrPath, String filePath, String refName) throws GitLabApiException {
+        return (getTreeStream(projectIdOrPath, filePath, refName, false));
+    }
+
     /**
      * Get a list of repository files and directories in a project.
      *
@@ -389,14 +436,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      */
     public List<TreeItem> getTree(Object projectIdOrPath, String filePath, String refName, Boolean recursive) throws GitLabApiException {
-        Form formData = new GitLabApiForm()
-                .withParam("id", getProjectIdOrPath(projectIdOrPath), true)
-                .withParam("path", filePath, false)
-                .withParam(isApiVersion(ApiVersion.V3) ? "ref_name" : "ref", refName, false)
-                .withParam("recursive", recursive, false)
-                .withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "projects", getProjectIdOrPath(projectIdOrPath), "repository", "tree");
-        return (response.readEntity(new GenericType<List<TreeItem>>() {}));
+        return (getTree(projectIdOrPath, filePath, refName, recursive, getDefaultPerPage()).all());
     }
 
     /**
@@ -427,6 +467,27 @@ public class RepositoryApi extends AbstractApi {
                 getProjectIdOrPath(projectIdOrPath), "repository", "tree"));
     }
 
+    /**
+     * Get a Stream of repository files and directories in a project.
+     *
+     * GET /projects/:id/repository/tree
+     *
+     * id (required) - The ID of a project
+     * path (optional) - The path inside repository. Used to get contend of subdirectories
+     * ref_name (optional) - The name of a repository branch or tag or if not given the default branch
+     * recursive (optional) - Boolean value used to get a recursive tree (false by default)
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @param filePath the path inside repository, used to get content of subdirectories
+     * @param refName the name of a repository branch or tag or if not given the default branch
+     * @param recursive flag to get a recursive tree or not
+     * @return a Stream containing a tree with the directories and files of a project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<TreeItem> getTreeStream(Object projectIdOrPath, String filePath, String refName, Boolean recursive) throws GitLabApiException {
+        return (getTree(projectIdOrPath, filePath, refName, recursive, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get the raw file contents for a blob by blob SHA.
      *
@@ -634,7 +695,7 @@ public class RepositoryApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      */
     public List<Contributor> getContributors(Object projectIdOrPath) throws GitLabApiException {
-        return (getContributors(projectIdOrPath, 1, getDefaultPerPage()));
+        return (getContributors(projectIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
@@ -668,4 +729,17 @@ public class RepositoryApi extends AbstractApi {
         return new Pager<Contributor>(this, Contributor.class, itemsPerPage, null, "projects",
                 getProjectIdOrPath(projectIdOrPath), "repository", "contributors");
     }
+
+    /**
+     * Get a list of contributors from a project.
+     *
+     * GET /projects/:id/repository/contributors
+     *
+     * @param projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance
+     * @return a List containing the contributors for the specified project ID
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Contributor> getContributorsStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getContributors(projectIdOrPath, getDefaultPerPage()).stream());
+    }
 }

src/main/java/org/gitlab4j/api/TagsApi.java

@@ -4,6 +4,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -28,22 +29,20 @@ public class TagsApi extends AbstractApi {
     /**
      * Get a list of repository tags from a project, sorted by name in reverse alphabetical order.
      *
-     * GET /projects/:id/repository/tags
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @return the list of tags for the specified project ID
      * @throws GitLabApiException if any exception occurs
      */
     public List<Tag> getTags(Object projectIdOrPath) throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(),
-                "projects", getProjectIdOrPath(projectIdOrPath), "repository", "tags");
-        return (response.readEntity(new GenericType<List<Tag>>() { }));
+        return (getTags(projectIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of repository tags from a project, sorted by name in reverse alphabetical order and in the specified page range.
      *
-     * GET /projects/:id/repository/tags
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param page the page to get
@@ -60,7 +59,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Get a list of repository tags from a project, sorted by name in reverse alphabetical order.
      *
-     * GET /projects/:id/repository/tags
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param itemsPerPage the number of Project instances that will be fetched per page
@@ -71,10 +70,23 @@ public class TagsApi extends AbstractApi {
         return (new Pager<Tag>(this, Tag.class, itemsPerPage, null, "projects", getProjectIdOrPath(projectIdOrPath), "repository", "tags"));
     }
 
+    /**
+     * Get a Stream of repository tags from a project, sorted by name in reverse alphabetical order.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags</code></pre>
+     *
+     * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
+     * @return a Stream of tags for the specified project ID
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Tag> getTagsStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getTags(projectIdOrPath, getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a specific repository tag determined by its name.
      *
-     * GET /projects/:id/repository/tags/:tagName
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags/:tagName</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName the name of the tag to fetch the info for
@@ -89,7 +101,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Get an Optional instance holding a Tag instance of a specific repository tag determined by its name.
      *
-     * GET /projects/:id/repository/tags/:tagName
+     * <pre><code>GitLab Endpoint: GET /projects/:id/repository/tags/:tagName</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName the name of the tag to fetch the info for
@@ -107,7 +119,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Creates a tag on a particular ref of the given project. A message and release notes are optional.
      *
-     * POST /projects/:id/repository/tags
+     * <pre><code>GitLab Endpoint: POST /projects/:id/repository/tags</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName The name of the tag Must be unique for the project
@@ -134,7 +146,7 @@ public class TagsApi extends AbstractApi {
      * release notes are optional. This method is the same as {@link #createTag(Object, String, String, String, String)},
      * but instead allows the release notes to be supplied in a file.
      *
-     * POST /projects/:id/repository/tags
+     * <pre><code>GitLab Endpoint: POST /projects/:id/repository/tags</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName the name of the tag, must be unique for the project
@@ -163,7 +175,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Deletes the tag from a project with the specified tag name.
      *
-     * DELETE /projects/:id/repository/tags/:tag_name
+     * <pre><code>GitLab Endpoint: DELETE /projects/:id/repository/tags/:tag_name</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName The name of the tag to delete
@@ -177,7 +189,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Add release notes to the existing git tag.
      *
-     * POST /projects/:id/repository/tags/:tagName/release
+     * <pre><code>GitLab Endpoint: POST /projects/:id/repository/tags/:tagName/release</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName the name of a tag
@@ -195,7 +207,7 @@ public class TagsApi extends AbstractApi {
     /**
      * Updates the release notes of a given release.
      *
-     * PUT /projects/:id/repository/tags/:tagName/release
+     * <pre><code>GitLab Endpoint: PUT /projects/:id/repository/tags/:tagName/release</code></pre>
      *
      * @param projectIdOrPath id, path of the project, or a Project instance holding the project ID or path
      * @param tagName the name of a tag

src/main/java/org/gitlab4j/api/UserApi.java

@@ -14,6 +14,7 @@ import java.util.Date;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 /**
  * This class provides an entry point to all the GitLab API users calls.
@@ -41,23 +42,21 @@ public class UserApi extends AbstractApi {
     }
 
     /**
-     * Get a list of users. Only returns the first page
-     * <p>
-     * GET /users
+     * Get a list of users.
      *
-     * @return a list of Users, this list will only contain the first 100 users in the system.
+     * <pre><code>GitLab Endpoint: GET /users</code></pre>
+     *
+     * @return a list of Users
      * @throws GitLabApiException if any exception occurs
      */
     public List<User> getUsers() throws GitLabApiException {
-        Response response = get(Response.Status.OK, getDefaultPerPageParam(customAttributesEnabled), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (getUsers(getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of users using the specified page and per page settings.
-     * <p>
-     * GET /users
+     *
+     * <pre><code>GitLab Endpoint: GET /users</code></pre>
      *
      * @param page    the page to get
      * @param perPage the number of users per page
@@ -66,14 +65,13 @@ public class UserApi extends AbstractApi {
      */
     public List<User> getUsers(int page, int perPage) throws GitLabApiException {
         Response response = get(Response.Status.OK, getPageQueryParams(page, perPage, customAttributesEnabled), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (response.readEntity(new GenericType<List<User>>() {}));
     }
 
     /**
      * Get a Pager of users.
-     * <p>
-     * GET /users
+     *
+     * <pre><code>GitLab Endpoint: GET /users</code></pre>
      *
      * @param itemsPerPage the number of User instances that will be fetched per page
      * @return a Pager of User
@@ -84,28 +82,35 @@ public class UserApi extends AbstractApi {
     }
 
     /**
-     * Get a list of active users. Only returns the first page
-     * <p>
-     * GET /users?active=true
+     * Get a Stream of users.
+     *
+     * <pre><code>GitLab Endpoint: GET /users</code></pre>
+     *
+     * @return a Stream of Users.
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<User> getUsersStream() throws GitLabApiException {
+        return (getUsers(getDefaultPerPage()).stream());
+    }
+
+    /**
+     * Get a list of active users
+     *
+     * <pre><code>GitLab Endpoint: GET /users?active=true</code></pre>
      *
-     * @return a list of active Users, this list will only contain the first 100 users in the system.
+     * @return a list of active Users
      * @throws GitLabApiException if any exception occurs
      */
     public List<User> getActiveUsers() throws GitLabApiException {
-        GitLabApiForm formData = createGitLabApiForm()
-                .withParam("active", true)
-                .withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (getActiveUsers(getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of active users using the specified page and per page settings.
-     * <p>
-     * GET /users?active=true
      *
-     * @param page    the page to get
+     * <pre><code>GitLab Endpoint: GET /users?active=true</code></pre>
+     *
+     * @param page the page to get
      * @param perPage the number of users per page
      * @return the list of active Users in the specified range
      * @throws GitLabApiException if any exception occurs
@@ -116,14 +121,13 @@ public class UserApi extends AbstractApi {
                 .withParam(PAGE_PARAM, page)
                 .withParam(PER_PAGE_PARAM, perPage);
         Response response = get(Response.Status.OK, formData.asMap(), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (response.readEntity(new GenericType<List<User>>() {}));
     }
 
     /**
      * Get a Pager of active users.
-     * <p>
-     * GET /users?active=true
+     *
+     * <pre><code>GitLab Endpoint: GET /users?active=true</code></pre>
      *
      * @param itemsPerPage the number of active User instances that will be fetched per page
      * @return a Pager of active User
@@ -134,10 +138,22 @@ public class UserApi extends AbstractApi {
         return (new Pager<User>(this, User.class, itemsPerPage, formData.asMap(), "users"));
     }
 
+    /**
+     * Get a Stream of active users
+     *
+     * <pre><code>GitLab Endpoint: GET /users?active=true</code></pre>
+     *
+     * @return a Stream of active Users
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<User> getActiveUsersStream() throws GitLabApiException {
+        return (getActiveUsers(getDefaultPerPage()).stream());
+    }
+
     /**
      * Blocks the specified user. Available only for admin.
-     * <p>
-     * POST /users/:id/block
+     *
+     * <pre><code>GitLab Endpoint: POST /users/:id/block</code></pre>
      *
      * @param userId the ID of the user to block
      * @throws GitLabApiException if any exception occurs
@@ -156,8 +172,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Unblocks the specified user. Available only for admin.
-     * <p>
-     * POST /users/:id/unblock
+     *
+     * <pre><code>GitLab Endpoint: POST /users/:id/unblock</code></pre>
      *
      * @param userId the ID of the user to unblock
      * @throws GitLabApiException if any exception occurs
@@ -176,26 +192,21 @@ public class UserApi extends AbstractApi {
     }
 
     /**
-     * Get a list of blocked users. Only returns the first page
-     * <p>
-     * GET /users?blocked=true
+     * Get a list of blocked users.
      *
-     * @return a list of blocked Users, this list will only contain the first 100 users in the system.
+     * <pre><code>GitLab Endpoint: GET /users?blocked=true</code></pre>
+     *
+     * @return a list of blocked Users
      * @throws GitLabApiException if any exception occurs
      */
     public List<User> getBlockedUsers() throws GitLabApiException {
-        GitLabApiForm formData = createGitLabApiForm()
-                .withParam("blocked", true)
-                .withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (getBlockedUsers(getDefaultPerPage()).all());
     }
 
     /**
      * Get a list of blocked users using the specified page and per page settings.
-     * <p>
-     * GET /users?blocked=true
+     *
+     * <pre><code>GitLab Endpoint: GET /users?blocked=true</code></pre>
      *
      * @param page    the page to get
      * @param perPage the number of users per page
@@ -208,14 +219,13 @@ public class UserApi extends AbstractApi {
                 .withParam(PAGE_PARAM, page)
                 .withParam(PER_PAGE_PARAM, perPage);
         Response response = get(Response.Status.OK, formData.asMap(), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (response.readEntity(new GenericType<List<User>>() {}));
     }
 
     /**
      * Get a Pager of blocked users.
-     * <p>
-     * GET /users?blocked=true
+     *
+     * <pre><code>GitLab Endpoint: GET /users?blocked=true</code></pre>
      *
      * @param itemsPerPage the number of blocked User instances that will be fetched per page
      * @return a Pager of blocked User
@@ -226,10 +236,22 @@ public class UserApi extends AbstractApi {
         return (new Pager<User>(this, User.class, itemsPerPage, formData.asMap(), "users"));
     }
 
+    /**
+     * Get a Stream of blocked users.
+     *
+     * <pre><code>GitLab Endpoint: GET /users?blocked=true</code></pre>
+     *
+     * @return a Stream of blocked Users
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<User> getBlockedUsersStream() throws GitLabApiException {
+        return (getBlockedUsers(getDefaultPerPage()).stream());
+    }
+
     /**
      * Get a single user.
-     * <p>
-     * GET /users/:id
+     *
+     * <pre><code>GitLab Endpoint: GET /users/:id</code></pre>
      *
      * @param userId the ID of the user to get
      * @return the User instance for the specified user ID
@@ -243,8 +265,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Get a single user as an Optional instance.
-     * <p>
-     * GET /users/:id
+     *
+     * <pre><code>GitLab Endpoint: GET /users/:id</code></pre>
      *
      * @param userId the ID of the user to get
      * @return the User for the specified user ID as an Optional instance
@@ -259,10 +281,10 @@ public class UserApi extends AbstractApi {
 
     /**
      * Lookup a user by username.
-     * <p>
-     * NOTE: This is for admin users only.
-     * <p>
-     * GET /users?username=:username
+     *
+     * <p>NOTE: This is for admin users only.</p>
+     *
+     * <pre><code>GitLab Endpoint: GET /users?username=:username</code></pre>
      *
      * @param username the username of the user to get
      * @return the User instance for the specified username
@@ -271,17 +293,16 @@ public class UserApi extends AbstractApi {
     public User getUser(String username) throws GitLabApiException {
         GitLabApiForm formData = createGitLabApiForm().withParam("username", username, true);
         Response response = get(Response.Status.OK, formData.asMap(), "users");
-        List<User> users = response.readEntity(new GenericType<List<User>>() {
-        });
+        List<User> users = response.readEntity(new GenericType<List<User>>() {});
         return (users.isEmpty() ? null : users.get(0));
     }
 
     /**
      * Lookup a user by username and return an Optional instance.
-     * <p>
-     * NOTE: This is for admin users only.
-     * <p>
-     * GET /users?username=:username
+     *
+     * <p>NOTE: This is for admin users only.</p>
+     *
+     * <pre><code>GitLab Endpoint: GET /users?username=:username</code></pre>
      *
      * @param username the username of the user to get
      * @return the User for the specified username as an Optional instance
@@ -296,26 +317,21 @@ public class UserApi extends AbstractApi {
 
     /**
      * Search users by Email or username
-     * <p>
-     * GET /users?search=:email_or_username
+     *
+     * <pre><code>GitLab Endpoint: GET /users?search=:email_or_username</code></pre>
      *
      * @param emailOrUsername the email or username to search for
      * @return the User List with the email or username like emailOrUsername
      * @throws GitLabApiException if any exception occurs
      */
     public List<User> findUsers(String emailOrUsername) throws GitLabApiException {
-        GitLabApiForm formData = createGitLabApiForm()
-                .withParam("search", emailOrUsername, true)
-                .withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "users");
-        return (response.readEntity(new GenericType<List<User>>() {
-        }));
+        return (findUsers(emailOrUsername, getDefaultPerPage()).all());
     }
 
     /**
      * Search users by Email or username in the specified page range.
-     * <p>
-     * GET /users?search=:email_or_username
+     *
+     * <pre><code>GitLab Endpoint: GET /users?search=:email_or_username</code></pre>
      *
      * @param emailOrUsername the email or username to search for
      * @param page            the page to get
@@ -335,8 +351,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Search users by Email or username and return a Pager
-     * <p>
-     * GET /users?search=:email_or_username
+     *
+     * <pre><code>GitLab Endpoint: GET /users?search=:email_or_username</code></pre>
      *
      * @param emailOrUsername the email or username to search for
      * @param itemsPerPage    the number of Project instances that will be fetched per page
@@ -348,16 +364,29 @@ public class UserApi extends AbstractApi {
         return (new Pager<User>(this, User.class, itemsPerPage, formData.asMap(), "users"));
     }
 
+    /**
+     * Search users by Email or username.
+     *
+     * <pre><code>GitLab Endpoint: GET /users?search=:email_or_username</code></pre>
+     *
+     * @param emailOrUsername the email or username to search for
+     * @return a Stream of User instances with the email or username like emailOrUsername
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<User> findUsersStream(String emailOrUsername) throws GitLabApiException {
+        return (findUsers(emailOrUsername, getDefaultPerPage()).stream());
+    }
+
     /**
      * <p>Creates a new user. Note only administrators can create new users.
-     * Either password or reset_password should be specified (reset_password takes priority).
-     * <p>
-     * If both the User object's projectsLimit and the parameter projectsLimit is specified
+     * Either password or reset_password should be specified (reset_password takes priority).</p>
+     *
+     * <p>If both the User object's projectsLimit and the parameter projectsLimit is specified
      * the parameter will take precedence.</p>
      *
-     * <pre>POST /users</pre>
-     * <p>
-     * The following properties of the provided User instance can be set during creation:<pre><code> email (required) - Email
+     * <pre><code>GitLab Endpoint: POST /users</code></pre>
+     *
+     * <p>The following properties of the provided User instance can be set during creation:<pre><code> email (required) - Email
      * username (required) - Username
      * name (required) - Name
      * skype (optional) - Skype ID
@@ -394,9 +423,9 @@ public class UserApi extends AbstractApi {
      * <p>Creates a new user. Note only administrators can create new users.
      * Either password or resetPassword should be specified (resetPassword takes priority).</p>
      *
-     * <pre>POST /users</pre>
-     * <p>
-     * The following properties of the provided User instance can be set during creation:<pre><code> email (required) - Email
+     * <pre><code>GitLab Endpoint: POST /users</code></pre>
+     * 
+     * <p>The following properties of the provided User instance can be set during creation:<pre><code> email (required) - Email
      * username (required) - Username
      * name (required) - Name
      * skype (optional) - Skype ID
@@ -431,9 +460,9 @@ public class UserApi extends AbstractApi {
     /**
      * <p>Modifies an existing user. Only administrators can change attributes of a user.</p>
      *
-     * <pre>PUT /users</pre>
-     * <p>
-     * The following properties of the provided User instance can be set during update:<pre><code> email (required) - Email
+     * <pre><code>GitLab Endpoint: PUT /users</code></pre>
+     *
+     * <p>The following properties of the provided User instance can be set during update:<pre><code> email (required) - Email
      * username (required) - Username
      * name (required) - Name
      * skype (optional) - Skype ID
@@ -467,9 +496,9 @@ public class UserApi extends AbstractApi {
     /**
      * Modifies an existing user. Only administrators can change attributes of a user.
      *
-     * <pre>PUT /users/:id</pre>
-     * <p>
-     * The following properties of the provided User instance can be set during update:<pre><code> email (required) - Email
+     * <pre><code>GitLab Endpoint: PUT /users/:id</code></pre>
+     *
+     * <p>The following properties of the provided User instance can be set during update:<pre><code> email (required) - Email
      * username (required) - Username
      * name (required) - Name
      * skype (optional) - Skype ID
@@ -505,67 +534,36 @@ public class UserApi extends AbstractApi {
 
     /**
      * Deletes a user. Available only for administrators.
-     * <p>
-     * DELETE /users/:id
      *
-     * @param userId the user ID to delete
-     * @throws GitLabApiException if any exception occurs
-     */
-    public void deleteUser(Integer userId) throws GitLabApiException {
-        deleteUser(userId, null);
-    }
-
-    /**
-     * Deletes a user. Available only for administrators.
-     * <p>
-     * DELETE /users/:id
+     * <pre><code>GitLab Endpoint: DELETE /users/:id</code></pre>
      *
-     * @param userId     the user ID to delete
-     * @param hardDelete If true, contributions that would usually be moved to the
-     *                   ghost user will be deleted instead, as well as groups owned solely by this user
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteUser(Integer userId, Boolean hardDelete) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
-
-        GitLabApiForm formData = new GitLabApiForm().withParam("hard_delete ", hardDelete);
-        Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, formData.asMap(), "users", userId);
+    public void deleteUser(Object userIdOrUsername) throws GitLabApiException {
+        deleteUser(userIdOrUsername, null);
     }
 
     /**
      * Deletes a user. Available only for administrators.
-     * <p>
-     * DELETE /users/:id
      *
-     * @param user the User instance to delete
-     * @throws GitLabApiException if any exception occurs
-     */
-    public void deleteUser(User user) throws GitLabApiException {
-        deleteUser(user.getId(), null);
-    }
-
-    /**
-     * Deletes a user. Available only for administrators.
-     * <p>
-     * DELETE /users/:id
+     * <pre><code>GitLab Endpoint: DELETE /users/:id</code></pre>
      *
-     * @param user       the User instance to delete
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param hardDelete If true, contributions that would usually be moved to the
      *                   ghost user will be deleted instead, as well as groups owned solely by this user
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteUser(User user, Boolean hardDelete) throws GitLabApiException {
-        deleteUser(user.getId(), hardDelete);
+    public void deleteUser(Object userIdOrUsername, Boolean hardDelete) throws GitLabApiException {
+        GitLabApiForm formData = new GitLabApiForm().withParam("hard_delete ", hardDelete);
+        Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
+        delete(expectedStatus, formData.asMap(), "users", getUserIdOrUsername(userIdOrUsername));
     }
 
     /**
      * Get currently authenticated user.
-     * <p>
-     * GET /user
+     *
+     * <pre><code>GitLab Endpoint: GET /user</code></pre>
      *
      * @return the User instance for the currently authenticated user
      * @throws GitLabApiException if any exception occurs
@@ -577,24 +575,23 @@ public class UserApi extends AbstractApi {
 
     /**
      * Get a list of currently authenticated user's SSH keys.
-     * <p>
-     * GET /user/keys
+     *
+     * <pre><code>GitLab Endpoint: GET /user/keys</code></pre>
      *
      * @return a list of currently authenticated user's SSH keys
      * @throws GitLabApiException if any exception occurs
      */
     public List<SshKey> getSshKeys() throws GitLabApiException {
         Response response = get(Response.Status.OK, getDefaultPerPageParam(), "user", "keys");
-        return (response.readEntity(new GenericType<List<SshKey>>() {
-        }));
+        return (response.readEntity(new GenericType<List<SshKey>>() {}));
     }
 
     /**
      * Get a list of a specified user's SSH keys. Available only for admin users.
-     * <p>
-     * GET /users/:id/keys
      *
-     * @param userId the ID of the user to get SSH keys for
+     * <pre><code>GitLab Endpoint: GET /users/:id/keys</code></pre>
+     *
+     * @param userId the user ID to get the SSH keys for
      * @return a list of a specified user's SSH keys
      * @throws GitLabApiException if any exception occurs
      */
@@ -605,14 +602,10 @@ public class UserApi extends AbstractApi {
         }
 
         Response response = get(Response.Status.OK, getDefaultPerPageParam(), "users", userId, "keys");
-        List<SshKey> keys = response.readEntity(new GenericType<List<SshKey>>() {
-        });
-        if (keys == null) {
-            return (keys);
-        }
+        List<SshKey> keys = response.readEntity(new GenericType<List<SshKey>>() {});
 
-        for (SshKey key : keys) {
-            key.setUserId(userId);
+        if (keys != null) {
+            keys.forEach(key -> key.setUserId(userId));
         }
 
         return (keys);
@@ -620,8 +613,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Get a single SSH Key.
-     * <p>
-     * GET /user/keys/:key_id
+     *
+     * <pre><code>GitLab Endpoint: GET /user/keys/:key_id</code></pre>
      *
      * @param keyId the ID of the SSH key.
      * @return an SshKey instance holding the info on the SSH key specified by keyId
@@ -634,8 +627,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Get a single SSH Key as an Optional instance.
-     * <p>
-     * GET /user/keys/:key_id
+     *
+     * <pre><code>GitLab Endpoint: GET /user/keys/:key_id</code></pre>
      *
      * @param keyId the ID of the SSH key
      * @return an SshKey as an Optional instance holding the info on the SSH key specified by keyId
@@ -650,8 +643,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Creates a new key owned by the currently authenticated user.
-     * <p>
-     * POST /user/keys
+     *
+     * <pre><code>GitLab Endpoint: POST /user/keys</code></pre>
      *
      * @param title the new SSH Key's title
      * @param key   the new SSH key
@@ -666,8 +659,8 @@ public class UserApi extends AbstractApi {
 
     /**
      * Create new key owned by specified user. Available only for admin users.
-     * <p>
-     * POST /users/:id/keys
+     *
+     * <pre><code>GitLab Endpoint: POST /users/:id/keys</code></pre>
      *
      * @param userId the ID of the user to add the SSH key for
      * @param title  the new SSH Key's title
@@ -694,8 +687,8 @@ public class UserApi extends AbstractApi {
     /**
      * Deletes key owned by currently authenticated user. This is an idempotent function and calling it
      * on a key that is already deleted or not available results in success.
-     * <p>
-     * DELETE /user/keys/:key_id
+     *
+     * <pre><code>GitLab Endpoint: DELETE /user/keys/:key_id</code></pre>
      *
      * @param keyId the key ID to delete
      * @throws GitLabApiException if any exception occurs
@@ -712,100 +705,86 @@ public class UserApi extends AbstractApi {
 
     /**
      * Deletes key owned by a specified user. Available only for admin users.
-     * <p>
-     * DELETE /users/:id/keys/:key_id
      *
-     * @param userId the user ID of the user to delete the key for
+     * <pre><code>GitLab Endpoint: DELETE /users/:id/keys/:key_id</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param keyId  the key ID to delete
      * @throws GitLabApiException if any exception occurs
      */
-    public void deleteSshKey(Integer userId, Integer keyId) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
+    public void deleteSshKey(Object userIdOrUsername, Integer keyId) throws GitLabApiException {
 
         if (keyId == null) {
             throw new RuntimeException("keyId cannot be null");
         }
 
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, null, "users", userId, "keys", keyId);
+        delete(expectedStatus, null, "users", getUserIdOrUsername(userIdOrUsername), "keys", keyId);
     }
 
     /**
      * Get a list of a specified user's impersonation tokens.  Available only for admin users.
-     * <p>
-     * GET /users/:id/impersonation_tokens
      *
-     * @param userId the ID of the user to get impersonation tokens for
+     * <pre><code>GitLab Endpoint: GET /users/:id/impersonation_tokens</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @return a list of a specified user's impersonation tokens
      * @throws GitLabApiException if any exception occurs
      */
-    public List<ImpersonationToken> getImpersonationTokens(Integer userId) throws GitLabApiException {
-        return (getImpersonationTokens(userId, null));
+    public List<ImpersonationToken> getImpersonationTokens(Object userIdOrUsername) throws GitLabApiException {
+        return (getImpersonationTokens(userIdOrUsername, null));
     }
 
     /**
      * Get a list of a specified user's impersonation tokens.  Available only for admin users.
-     * <p>
-     * GET /users/:id/impersonation_tokens
      *
-     * @param userId the ID of the user to get impersonation tokens for
+     * <pre><code>GitLab Endpoint: GET /users/:id/impersonation_tokens</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param state  the state of impersonation tokens to list (ALL, ACTIVE, INACTIVE)
      * @return a list of a specified user's impersonation tokens
      * @throws GitLabApiException if any exception occurs
      */
-    public List<ImpersonationToken> getImpersonationTokens(Integer userId, ImpersonationState state) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
-
+    public List<ImpersonationToken> getImpersonationTokens(Object userIdOrUsername, ImpersonationState state) throws GitLabApiException {
         GitLabApiForm formData = new GitLabApiForm()
                 .withParam("state", state)
                 .withParam(PER_PAGE_PARAM, getDefaultPerPage());
-        Response response = get(Response.Status.OK, formData.asMap(), "users", userId, "impersonation_tokens");
-        return (response.readEntity(new GenericType<List<ImpersonationToken>>() {
-        }));
+        Response response = get(Response.Status.OK, formData.asMap(), "users", getUserIdOrUsername(userIdOrUsername), "impersonation_tokens");
+        return (response.readEntity(new GenericType<List<ImpersonationToken>>() {}));
     }
 
     /**
      * Get an impersonation token of a user.  Available only for admin users.
-     * <p>
-     * GET /users/:user_id/impersonation_tokens/:impersonation_token_id
      *
-     * @param userId  the ID of the user to get SSH keys for
+     * <pre><code>GitLab Endpoint: GET /users/:user_id/impersonation_tokens/:impersonation_token_id</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param tokenId the impersonation token ID to get
      * @return the specified impersonation token
      * @throws GitLabApiException if any exception occurs
      */
-    public ImpersonationToken getImpersonationToken(Integer userId, Integer tokenId) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
+    public ImpersonationToken getImpersonationToken(Object userIdOrUsername, Integer tokenId) throws GitLabApiException {
 
         if (tokenId == null) {
             throw new RuntimeException("tokenId cannot be null");
         }
 
-        Response response = get(Response.Status.OK, null, "users", userId, "impersonation_tokens", tokenId);
+        Response response = get(Response.Status.OK, null, "users", getUserIdOrUsername(userIdOrUsername), "impersonation_tokens", tokenId);
         return (response.readEntity(ImpersonationToken.class));
     }
 
     /**
      * Get an impersonation token of a user as an Optional instance. Available only for admin users.
-     * <p>
-     * GET /users/:user_id/impersonation_tokens/:impersonation_token_id
      *
-     * @param userId  the ID of the user to get SSH keys for
+     * <pre><code>GitLab Endpoint: GET /users/:user_id/impersonation_tokens/:impersonation_token_id</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param tokenId the impersonation token ID to get
      * @return the specified impersonation token as an Optional instance
      */
-    public Optional<ImpersonationToken> getOptionalImpersonationToken(Integer userId, Integer tokenId) {
+    public Optional<ImpersonationToken> getOptionalImpersonationToken(Object userIdOrUsername, Integer tokenId) {
         try {
-            return (Optional.ofNullable(getImpersonationToken(userId, tokenId)));
+            return (Optional.ofNullable(getImpersonationToken(userIdOrUsername, tokenId)));
         } catch (GitLabApiException glae) {
             return (GitLabApi.createOptionalFromException(glae));
         }
@@ -813,21 +792,17 @@ public class UserApi extends AbstractApi {
 
     /**
      * Create an impersonation token.  Available only for admin users.
-     * <p>
-     * POST /users/:user_id/impersonation_tokens
      *
-     * @param userId    the ID of the user to get SSH keys for
-     * @param name      the name of the impersonation token, required
+     * <pre><code>GitLab Endpoint: POST /users/:user_id/impersonation_tokens</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
+     * @param name the name of the impersonation token, required
      * @param expiresAt the expiration date of the impersonation token, optional
-     * @param scopes    an array of scopes of the impersonation token
+     * @param scopes an array of scopes of the impersonation token
      * @return the created ImpersonationToken instance
      * @throws GitLabApiException if any exception occurs
      */
-    public ImpersonationToken createImpersonationToken(Integer userId, String name, Date expiresAt, Scope[] scopes) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
+    public ImpersonationToken createImpersonationToken(Object userIdOrUsername, String name, Date expiresAt, Scope[] scopes) throws GitLabApiException {
 
         if (scopes == null || scopes.length == 0) {
             throw new RuntimeException("scopes cannot be null or empty");
@@ -841,31 +816,27 @@ public class UserApi extends AbstractApi {
             formData.withParam("scopes[]", scope.toString());
         }
 
-        Response response = post(Response.Status.CREATED, formData, "users", userId, "impersonation_tokens");
+        Response response = post(Response.Status.CREATED, formData, "users", getUserIdOrUsername(userIdOrUsername), "impersonation_tokens");
         return (response.readEntity(ImpersonationToken.class));
     }
 
     /**
      * Revokes an impersonation token. Available only for admin users.
-     * <p>
-     * DELETE /users/:user_id/impersonation_tokens/:impersonation_token_id
      *
-     * @param userId  the user ID of the user to revoke the impersonation token for
+     * <pre><code>GitLab Endpoint: DELETE /users/:user_id/impersonation_tokens/:impersonation_token_id</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param tokenId the impersonation token ID to revoke
      * @throws GitLabApiException if any exception occurs
      */
-    public void revokeImpersonationToken(Integer userId, Integer tokenId) throws GitLabApiException {
-
-        if (userId == null) {
-            throw new RuntimeException("userId cannot be null");
-        }
+    public void revokeImpersonationToken(Object userIdOrUsername, Integer tokenId) throws GitLabApiException {
 
         if (tokenId == null) {
             throw new RuntimeException("tokenId cannot be null");
         }
 
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
-        delete(expectedStatus, null, "users", userId, "impersonation_tokens", tokenId);
+        delete(expectedStatus, null, "users", getUserIdOrUsername(userIdOrUsername), "impersonation_tokens", tokenId);
     }
 
     /**
@@ -878,11 +849,13 @@ public class UserApi extends AbstractApi {
      * @return the populated Form instance
      */
     Form userToForm(User user, Integer projectsLimit, CharSequence password, Boolean resetPassword, boolean create) {
+
         if (create) {
             if ((password == null || password.toString().trim().isEmpty()) && !resetPassword) {
                 throw new IllegalArgumentException("either password or reset_password must be set");
             }
         }
+
         projectsLimit = (projectsLimit == null) ? user.getProjectsLimit() : projectsLimit;
         String skipConfirmationFeildName = create ? "skip_confirmation" : "skip_reconfirmation";
 
@@ -912,31 +885,29 @@ public class UserApi extends AbstractApi {
     /**
      * Creates custom attribute for the given user
      *
-     * @param userId          to set the customAttributes for
-     * @param customAttribute to set
-     * @return createdCustomAttribute
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
+     * @param customAttribute the custom attribute to set
+     * @return the created CustomAttribute
      * @throws GitLabApiException on failure while setting customAttributes
      */
-    public CustomAttribute createCustomAttribute(final Integer userId, final CustomAttribute customAttribute) throws GitLabApiException {
+    public CustomAttribute createCustomAttribute(final Object userIdOrUsername, final CustomAttribute customAttribute) throws GitLabApiException {
         if (Objects.isNull(customAttribute)) {
             throw new IllegalArgumentException("CustomAttributes can't be null");
         }
-        return createCustomAttribute(userId, customAttribute.getKey(), customAttribute.getValue());
+        return createCustomAttribute(userIdOrUsername, customAttribute.getKey(), customAttribute.getValue());
     }
 
     /**
      * Creates custom attribute for the given user
      *
-     * @param userId to set the customAttributes for
-     * @param key    for the customAttribute
-     * @param value  for the customAttribute
-     * @return createdCustomAttribute
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
+     * @param key for the customAttribute
+     * @param value  or the customAttribute
+     * @return the created CustomAttribute
      * @throws GitLabApiException on failure while setting customAttributes
      */
-    public CustomAttribute createCustomAttribute(final Integer userId, final String key, final String value) throws GitLabApiException {
-        if (Objects.isNull(userId)) {
-            throw new IllegalArgumentException("UserId can't be null.");
-        }
+    public CustomAttribute createCustomAttribute(final Object userIdOrUsername, final String key, final String value) throws GitLabApiException {
+
         if (Objects.isNull(key) || key.trim().isEmpty()) {
             throw new IllegalArgumentException("Key can't be null or empty");
         }
@@ -944,73 +915,73 @@ public class UserApi extends AbstractApi {
             throw new IllegalArgumentException("Value can't be null or empty");
         }
 
-        GitLabApiForm formData = new GitLabApiForm()
-                .withParam("value", value);
-        Response response = put(Response.Status.OK, formData.asMap(), "users", userId, "custom_attributes", key);
+        GitLabApiForm formData = new GitLabApiForm().withParam("value", value);
+        Response response = put(Response.Status.OK, formData.asMap(),
+                "users", getUserIdOrUsername(userIdOrUsername), "custom_attributes", key);
         return (response.readEntity(CustomAttribute.class));
     }
 
     /**
      * Change custom attribute for the given user
      *
-     * @param userId          to change the customAttributes for
-     * @param customAttribute to change
-     * @return changedCustomAttribute
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
+     * @param customAttribute the custome attribute to change
+     * @return the changed CustomAttribute
      * @throws GitLabApiException on failure while changing customAttributes
      */
-    public CustomAttribute changeCustomAttribute(final Integer userId, final CustomAttribute customAttribute) throws GitLabApiException {
+    public CustomAttribute changeCustomAttribute(final Object userIdOrUsername, final CustomAttribute customAttribute) throws GitLabApiException {
+
         if (Objects.isNull(customAttribute)) {
             throw new IllegalArgumentException("CustomAttributes can't be null");
         }
 
         //changing & creating custom attributes is the same call in gitlab api
         // -> https://docs.gitlab.com/ce/api/custom_attributes.html#set-custom-attribute
-        return createCustomAttribute(userId, customAttribute.getKey(), customAttribute.getValue());
+        return createCustomAttribute(userIdOrUsername, customAttribute.getKey(), customAttribute.getValue());
     }
 
     /**
      * Changes custom attribute for the given user
      *
-     * @param userId to change the customAttribute for
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param key    for the customAttribute
      * @param value  for the customAttribute
      * @return changedCustomAttribute
      * @throws GitLabApiException on failure while changing customAttributes
      */
-    public CustomAttribute changeCustomAttribute(final Integer userId, final String key, final String value) throws GitLabApiException {
-        return createCustomAttribute(userId, key, value);
+    public CustomAttribute changeCustomAttribute(final Object userIdOrUsername, final String key, final String value) throws GitLabApiException {
+        return createCustomAttribute(userIdOrUsername, key, value);
     }
 
     /**
      * Delete a custom attribute for the given user
      *
-     * @param userId          to delete the customAttribute for
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param customAttribute to remove
      * @throws GitLabApiException on failure while deleting customAttributes
      */
-    public void deleteCustomAttribute(final Integer userId, final CustomAttribute customAttribute) throws GitLabApiException {
+    public void deleteCustomAttribute(final Object userIdOrUsername, final CustomAttribute customAttribute) throws GitLabApiException {
         if (Objects.isNull(customAttribute)) {
             throw new IllegalArgumentException("customAttributes can't be null");
         }
 
-        deleteCustomAttribute(userId, customAttribute.getKey());
+        deleteCustomAttribute(userIdOrUsername, customAttribute.getKey());
     }
 
     /**
      * Delete a custom attribute for the given user
      *
-     * @param userId to delete the customAttribute for
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
      * @param key    of the customAttribute to remove
      * @throws GitLabApiException on failure while deleting customAttributes
      */
-    public void deleteCustomAttribute(final Integer userId, final String key) throws GitLabApiException {
-        if (Objects.isNull(userId)) {
-            throw new IllegalArgumentException("UserId can't be null");
-        }
+    public void deleteCustomAttribute(final Object userIdOrUsername, final String key) throws GitLabApiException {
+
         if (Objects.isNull(key) || key.trim().isEmpty()) {
             throw new IllegalArgumentException("Key can't be null or empty");
         }
-        delete(Response.Status.OK, null, "users", userId, "custom_attributes", key);
+
+        delete(Response.Status.OK, null, "users", getUserIdOrUsername(userIdOrUsername), "custom_attributes", key);
     }
 
     /**