Add Epic and Epic Issues API support (#218)

README.md

@@ -11,7 +11,7 @@ To utilize the GitLab API for Java in your project, simply add the following dep
 ```java
 dependencies {
     ...
-    compile group: 'org.gitlab4j', name: 'gitlab4j-api', version: '4.8.29'
+    compile group: 'org.gitlab4j', name: 'gitlab4j-api', version: '4.8.30'
 }
 ```
 
@@ -20,7 +20,7 @@ dependencies {
 <dependency>
     <groupId>org.gitlab4j</groupId>
     <artifactId>gitlab4j-api</artifactId>
-    <version>4.8.29</version>
+    <version>4.8.30</version>
 </dependency>
 ```
 
@@ -137,6 +137,7 @@ The API has been broken up into sub APIs classes to make it easier to learn and
 ------------------
 &nbsp;&nbsp;[CommitsApi](#commitsapi)<br/>
 &nbsp;&nbsp;[DeployKeysApi](#deploykeysapi)<br/>
+&nbsp;&nbsp;[EpicsApi](#epicsapi)<br/>
 &nbsp;&nbsp;[EventsApi](#eventsapi)<br/>
 &nbsp;&nbsp;[GroupApi](#groupapi)<br/>
 &nbsp;&nbsp;[HealthCheckApi](#healthcheckapi)<br/>
@@ -179,10 +180,16 @@ List<Commit> commits = gitLabApi.getCommitsApi().getCommits(1234, "new-feature",
 List<DeployKey> deployKeys = gitLabApi.getDeployKeysApi().getDeployKeys();
 ```
 
+#### EpicsApi
+```java
+// Get a list epics of the requested group and its subgroups.
+List<Epic> epics = gitLabApi.getEpicsApi().getEpics(1);
+```
+
 #### EventsApi
 ```java
 // Get a list of Events for the authenticated user
-Date after = new Date(0); // After Eposc
+Date after = new Date(0); // After Epoch
 Date before = new Date(); // Before now
 List<Event> events = gitLabApi.getEventsApi().getAuthenticatedUserEvents(null, null, before, after, DESC);
 ```

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

@@ -59,6 +59,30 @@ public interface Constants {
         }
     }
 
+
+    /** Enum to use for ordering the results of getEpics(). */
+    public enum EpicOrderBy {
+
+        CREATED_AT, UPDATED_AT;
+
+        private static JacksonJsonEnumHelper<EpicOrderBy> enumHelper = new JacksonJsonEnumHelper<>(EpicOrderBy.class);
+
+        @JsonCreator
+        public static EpicOrderBy forValue(String value) {
+            return enumHelper.forValue(value);
+        }
+
+        @JsonValue
+        public String toValue() {
+            return (enumHelper.toString(this));
+        }
+
+        @Override
+        public String toString() {
+            return (enumHelper.toString(this));
+        }
+    }
+
     /** Enum to use for ordering the results of getProjects(). */
     public enum ProjectOrderBy {
 

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

+package org.gitlab4j.api;
+
+import java.util.Date;
+import java.util.List;
+import java.util.Optional;
+
+import javax.ws.rs.core.Form;
+import javax.ws.rs.core.GenericType;
+import javax.ws.rs.core.Response;
+
+import org.gitlab4j.api.models.Epic;
+import org.gitlab4j.api.models.EpicIssue;
+
+/**
+ * This class implements the client side API for the GitLab Epics and Epic Issues API calls.
+ * 
+ * NOTE:
+ *  - If a user is not a member of a group and the group is private, a GET request on that group will result to a 404 status code.
+ *  - Epics are available only in Ultimate. If epics feature is not available a 403 status code will be returned.
+ * 
+ * @see <a href="https://docs.gitlab.com/ee/api/epics.html">GitLab Epics API Documentaion</a>
+ * @see <a href="https://docs.gitlab.com/ee/api/epic_issues.html">GitLab Epic Issues API Documentation</a>
+ */
+public class EpicsApi extends AbstractApi {
+
+    public EpicsApi(GitLabApi gitLabApi) {
+        super(gitLabApi);
+    }
+
+    /**
+     * Gets all epics of the requested group and its subgroups.
+     * 
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @return a list of all epics of the requested group and its subgroups
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpics(Object groupIdOrPath) throws GitLabApiException {
+        return (getEpics(groupIdOrPath, 1, getDefaultPerPage()));
+    }
+
+    /**
+     * Gets all epics of the requested group and its subgroups using the specified page and per page setting.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @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 issues per page
+     * @return a list of all epics of the requested group and its subgroups in the specified range
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpics(Object groupIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", getGroupIdOrPath(groupIdOrPath), "epics");
+        return (response.readEntity(new GenericType<List<Epic>>() { }));
+    }
+
+    /**
+     * Get a Pager of all epics of the requested group and its subgroups.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param itemsPerPage the number of issues per page
+     * @return the Pager of all epics of the requested group and its subgroups
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Epic> getEpics(Object groupIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Epic>(this, Epic.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "epics"));
+    }
+
+    /**
+     * Gets all epics of the requested group and its subgroups.
+     * 
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param authorId returns epics created by the given user id
+     * @param labels return epics matching a comma separated list of labels names.
+     *        Label names from the epic group or a parent group can be used
+     * @param orderBy return epics ordered by CREATED_AT or UPDATED_AT. Default is CREATED_AT
+     * @param sortOrder return epics sorted in ASC or DESC order. Default is DESC
+     * @param search search epics against their title and description
+     * @return a list of matching epics of the requested group and its subgroups
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpics(Object groupIdOrPath, Integer authorId, String labels, EpicOrderBy orderBy,
+            SortOrder sortOrder, String search) throws GitLabApiException {
+        return (getEpics(groupIdOrPath, authorId, labels, orderBy, sortOrder, search, 1, getDefaultPerPage()));
+    }
+
+    /**
+     * Gets all epics of the requested group and its subgroups using the specified page and per page setting.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param authorId returns epics created by the given user id
+     * @param labels return epics matching a comma separated list of labels names
+     *        Label names from the epic group or a parent group can be used
+     * @param orderBy return epics ordered by CREATED_AT or UPDATED_AT. Default is CREATED_AT
+     * @param sortOrder return epics sorted in ASC or DESC order. Default is DESC
+     * @param search search epics against their title and description
+     * @param page the page to get
+     * @param perPage the number of issues per page
+     * @return a list of matching epics of the requested group and its subgroups in the specified range
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpics(Object groupIdOrPath, Integer authorId, String labels,
+            EpicOrderBy orderBy, SortOrder sortOrder, String search, int page, int perPage) throws GitLabApiException {
+        GitLabApiForm formData = new GitLabApiForm(page, perPage)
+                .withParam("author_id", authorId)
+                .withParam("labels", labels)
+                .withParam("order_by", orderBy)
+                .withParam("sort", sortOrder)
+                .withParam("search", search);
+        Response response = get(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "epics");
+        return (response.readEntity(new GenericType<List<Epic>>() { }));
+    }
+
+    /**
+     * Get a Pager of all epics of the requested group and its subgroups.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param authorId returns epics created by the given user id
+     * @param labels return epics matching a comma separated list of labels names.
+     *        Label names from the epic group or a parent group can be used
+     * @param itemsPerPage the number of issues per page
+     * @param orderBy return epics ordered by CREATED_AT or UPDATED_AT. Default is CREATED_AT
+     * @param sortOrder return epics sorted in ASC or DESC order. Default is DESC
+     * @param search search epics against their title and description
+     * @return the Pager of matching epics of the requested group and its subgroups
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Epic> getEpics(Object groupIdOrPath, Integer authorId, String labels,
+            EpicOrderBy orderBy, SortOrder sortOrder, String search, int itemsPerPage) throws GitLabApiException {
+        GitLabApiForm formData = new GitLabApiForm()
+                .withParam("author_id", authorId)
+                .withParam("labels", labels)
+                .withParam("order_by", orderBy)
+                .withParam("sort", sortOrder)
+                .withParam("search", search);
+        return (new Pager<Epic>(this, Epic.class, itemsPerPage, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "epics"));
+    }
+
+    /**
+     * Get a single epic for the specified group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics/:epic_iid</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to get
+     * @return an Epic instance for the specified Epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Epic getEpic(Object groupIdOrPath, Integer epicIid) throws GitLabApiException {
+        Response response = get(Response.Status.OK, null, "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid);
+        return (response.readEntity(Epic.class));
+    }
+
+    /**
+     * Get an Optional instance with the value for the specific Epic.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics/:epic_iid</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to get
+     * @return an Optional instance with the specified Epic as a value
+     */
+    public Optional<Epic> getOptionalEpic(Object groupIdOrPath, Integer epicIid) {
+        try {
+            return (Optional.ofNullable(getEpic(groupIdOrPath, epicIid)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
+    /**
+     * Creates a new epic.
+     *
+     * <pre><code>GitLab Endpoint: POST /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param title the title of the epic (required)
+     * @param labels comma separated list of labels (optional)
+     * @param description the description of the epic (optional)
+     * @param startDate the start date of the epic (optional)
+     * @param endDate the end date of the epic (optional)
+     * @return an Epic instance containing info on the newly created epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Epic createEpic(Object groupIdOrPath, String title, String labels, String description,
+            Date startDate, Date endDate) throws GitLabApiException {
+        Form formData = new GitLabApiForm()
+                .withParam("title", title, true)
+                .withParam("labels", labels)
+                .withParam("description", description)
+                .withParam("start_date", startDate)
+                .withParam("end_date", endDate);
+        Response response = post(Response.Status.CREATED, formData.asMap(),
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics");
+        return (response.readEntity(Epic.class));
+    }
+
+    /**
+     * Creates a new epic using the information contained in the provided Epic instance.  Only the following 
+     * fields from the Epic instance are used:
+     * <pre><code>
+     *      title - the title of the epic (required)
+     *      labels - comma separated list of labels (optional)
+     *      description - the description of the epic (optional)
+     *      startDate - the start date of the epic (optional)
+     *      endDate - the end date of the epic (optional) 
+     * </code></pre>
+     *
+     * <pre><code>GitLab Endpoint: POST /groups/:id/epics</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epic the Epic instance with information for the new epic
+     * @return an Epic instance containing info on the newly created epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Epic createEpic(Object groupIdOrPath, Epic epic) throws GitLabApiException {
+        Form formData = new GitLabApiForm()
+                .withParam("title", epic.getTitle(), true)
+                .withParam("labels", epic.getLabels())
+                .withParam("description", epic.getDescription())
+                .withParam("start_date", epic.getStartDate())
+                .withParam("end_date", epic.getEndDate());
+        Response response = post(Response.Status.CREATED, formData.asMap(),
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics");
+        return (response.readEntity(Epic.class));
+    }
+
+    /**
+     * Updates an existing epic.
+     *
+     * <pre><code>GitLab Endpoint: PUT /groups/:id/epics/:epic_iid</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to update
+     * @param title the title of the epic (optional)
+     * @param labels comma separated list of labels (optional)
+     * @param description the description of the epic (optional)
+     * @param startDate the start date of the epic (optional)
+     * @param endDate the end date of the epic (optional)
+     * @return an Epic instance containing info on the newly created epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Epic updateEpic(Object groupIdOrPath, Integer epicIid, String title, String labels, String description,
+            Date startDate, Date endDate) throws GitLabApiException {
+        Form formData = new GitLabApiForm()
+                .withParam("title", title, true)
+                .withParam("labels", labels)
+                .withParam("description", description)
+                .withParam("start_date", startDate)
+                .withParam("end_date", endDate);
+        Response response = put(Response.Status.CREATED, formData.asMap(),
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid);
+        return (response.readEntity(Epic.class));
+    }
+
+    /**
+     * Updates an epic using the information contained in the provided Epic instance.  Only the following 
+     * fields from the Epic instance are used:
+     * <pre><code>
+     *      title - the title of the epic (optional)
+     *      labels - comma separated list of labels (optional)
+     *      description - the description of the epic (optional)
+     *      startDate - the start date of the epic (optional)
+     *      endDate - the end date of the epic (optional) 
+     * </code></pre>
+     * <pre><code>GitLab Endpoint: PUT /groups/:id/epics/:epic_iid</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to update
+     * @param epic the Epic instance with update information
+     * @return an Epic instance containing info on the updated epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Epic updateEpic(Object groupIdOrPath, Integer epicIid, Epic epic) throws GitLabApiException {
+        Form formData = new GitLabApiForm()
+                .withParam("title", epic.getTitle(), true)
+                .withParam("labels", epic.getLabels())
+                .withParam("description", epic.getDescription())
+                .withParam("start_date", epic.getStartDate())
+                .withParam("end_date", epic.getEndDate());
+        Response response = put(Response.Status.CREATED, formData.asMap(),
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid);
+        return (response.readEntity(Epic.class));
+    }
+
+    /**
+     * Deletes an epic.
+     *
+     * <pre><code>GitLab Endpoint: DELETE /groups/:id/epics/:epic_iid</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to delete
+     * @throws GitLabApiException if any exception occurs
+     */
+    public void deleteEpic(Object groupIdOrPath, Integer epicIid) throws GitLabApiException {
+        delete(Response.Status.NO_CONTENT, null, "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid);
+    }
+    
+
+    /**
+     * Gets all issues that are assigned to an epic and the authenticated user has access to.
+     * 
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics/:epic_iid/issues</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to get issues for
+     * @return a list of all epic issues belonging to the specified epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpicIssues(Object groupIdOrPath, Integer epicIid) throws GitLabApiException {
+        return (getEpicIssues(groupIdOrPath, epicIid, 1, getDefaultPerPage()));
+    }
+
+    /**
+     * Gets all issues that are assigned to an epic and the authenticated user has access to
+     * using the specified page and per page setting.
+     * 
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics/:epic_iid/issues</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to get issues for
+     * @param page the page to get
+     * @param perPage the number of issues per page
+     * @return a list of all epic issues belonging to the specified epic in the specified range
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Epic> getEpicIssues(Object groupIdOrPath, Integer epicIid, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid, "issues");
+        return (response.readEntity(new GenericType<List<Epic>>() { }));
+    }
+
+    /**
+     * Get a Pager of all issues that are assigned to an epic and the authenticated user has access to.
+     * 
+     * <pre><code>GitLab Endpoint: GET /groups/:id/epics/:epic_iid/issues</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the IID of the epic to get issues for
+     * @param itemsPerPage the number of issues per page
+     * @return the Pager of all epic issues belonging to the specified epic
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Epic> getEpicIssues(Object groupIdOrPath, Integer epicIid, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Epic>(this, Epic.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid, "issues"));
+    }
+
+    /**
+     * Creates an epic - issue association. If the issue in question belongs to another epic
+     * it is unassigned from that epic.
+     *
+     * <pre><code>GitLab Endpoint: POST /groups/:id/epics/:epic_iid/issues/:issue_id</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the Epic IID to assign the issue to
+     * @param issueIid the issue IID of the issue to assign to the epic
+     * @return an EpicIssue instance containing info on the newly assigned epic issue
+     * @throws GitLabApiException if any exception occurs
+     */
+    public EpicIssue assignIssue(Object groupIdOrPath, Integer epicIid, Integer issueIid) throws GitLabApiException {
+        Response response = post(Response.Status.CREATED, (Form)null,
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid, "issues", issueIid);
+        return (response.readEntity(EpicIssue.class));
+    }
+
+    /**
+     * Remove an epic - issue association.
+     *
+     * <pre><code>GitLab Endpoint: DELETE /groups/:id/epics/:epic_iid/issues/:issue_id</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the Epic IID to remove the issue from
+     * @param issueIid the issue IID of the issue to remove from the epic
+     * @return an EpicIssue instance containing info on the removed issue
+     * @throws GitLabApiException if any exception occurs
+     */
+    public EpicIssue removeIssue(Object groupIdOrPath, Integer epicIid, Integer issueIid) throws GitLabApiException {
+        Response response = delete(Response.Status.CREATED, null,
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid, "issues", issueIid);
+        return (response.readEntity(EpicIssue.class));
+    }
+
+    /**
+     * Updates an epic - issue association.
+     *
+     * <pre><code>GitLab Endpoint: PUT /groups/:id/epics/:epic_iid/issues/:issue_id</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param epicIid the Epic IID that the issue is assigned to
+     * @param issueIid the issue IID to update
+     * @param moveBeforeId the ID of the issue - epic association that should be placed before the link in the question (optional)
+     * @param moveAfterId the ID of the issue - epic association that should be placed after the link in the question (optional)
+     * @return an EpicIssue instance containing info on the newly assigned epic issue
+     * @throws GitLabApiException if any exception occurs
+     */
+    public EpicIssue updateIssue(Object groupIdOrPath, Integer epicIid, Integer issueIid, Integer moveBeforeId, Integer moveAfterId) throws GitLabApiException {   
+        GitLabApiForm form = new GitLabApiForm()
+            .withParam("move_before_id", moveBeforeId)
+            .withParam("move_after_id", moveAfterId);
+        Response response = post(Response.Status.CREATED, form,
+                "groups", getGroupIdOrPath(groupIdOrPath), "epics", epicIid, "issues", issueIid);
+        return (response.readEntity(EpicIssue.class));
+    }
+}

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

@@ -50,6 +50,7 @@ public class GitLabApi {
 
     private CommitsApi commitsApi;
     private DeployKeysApi deployKeysApi;
+    private EpicsApi epicsApi;
     private EventsApi eventsApi;
     private GroupApi groupApi;
     private HealthCheckApi healthCheckApi;
@@ -846,6 +847,25 @@ public class GitLabApi {
         return (deployKeysApi);
     }
 
+    /**
+     * Gets the EpicsApi instance owned by this GitLabApi instance. The EpicsApi is used
+     * to perform all Epics and Epic Issues related API calls.
+     *
+     * @return the EpicsApi instance owned by this GitLabApi instance
+     */
+    public EpicsApi getEpicsApi() {
+
+        if (epicsApi == null) {
+            synchronized (this) {
+                if (epicsApi == null) {
+                    epicsApi = new EpicsApi(this);
+                }
+            }
+        }
+
+        return (epicsApi);
+    }
+
     /**
      * Gets the EventsApi instance owned by this GitLabApi instance. The EventsApi is used
      * to perform all events related API calls.

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

@@ -21,6 +21,18 @@ public class GitLabApiForm extends Form {
         super(map);
     }
 
+    /**
+     * Create a GitLabApiForm instance with the "page", and "per_page" parameters preset.
+     *
+     * @param page the value for the "page" parameter
+     * @param perPage the value for the "per_page" parameter
+     */
+    public GitLabApiForm(int page, int perPage) {
+        super();
+        withParam(AbstractApi.PAGE_PARAM,  page);
+        withParam(AbstractApi.PER_PAGE_PARAM, (Integer)perPage);
+    }
+
     /**
      * Fluent method for adding query and form parameters to a get() or post() call.
      * 

src/main/java/org/gitlab4j/api/models/Epic.java

+package org.gitlab4j.api.models;
+
+import java.util.Date;
+import java.util.List;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement
+@XmlAccessorType(XmlAccessType.FIELD)
+public class Epic {
+    
+    private Integer id;
+    private Integer iid;
+    private Integer groupId;
+    private String title;
+    private String description;
+    private Author author;
+    private List<String> labels;
+    private Date startDate;
+    private Date endDate;
+    private Date createdAt;
+    private Date updatedAt;
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public Integer getIid() {
+        return iid;
+    }
+
+    public void setIid(Integer iid) {
+        this.iid = iid;
+    }
+
+    public Integer getGroupId() {
+        return groupId;
+    }
+
+    public void setGroupId(Integer groupId) {
+        this.groupId = groupId;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+    
+    public Epic withTitle(String title) {
+        this.title = title;
+        return (this);
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public Epic withDescription(String description) {
+        this.description = description;
+        return (this);
+    }
+
+    public Author getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(Author author) {
+        this.author = author;
+    }
+
+    public Epic withAuthor(Author author) {
+        this.author = author;
+        return (this);
+    }
+
+    public List<String> getLabels() {
+        return labels;
+    }
+
+    public void setLabels(List<String> labels) {
+        this.labels = labels;
+    }
+
+    public Epic withLabels(List<String> labels) {
+        this.labels = labels;
+        return (this);
+    }
+
+    public Date getStartDate() {
+        return startDate;
+    }
+
+    public void setStartDate(Date startDate) {
+        this.startDate = startDate;
+    }
+
+    public Epic withStartDate(Date startDate) {
+        this.startDate = startDate;
+        return (this);
+    }
+
+    public Date getEndDate() {
+        return endDate;
+    }
+
+    public void setEndDate(Date endDate) {
+        this.endDate = endDate;
+    }
+
+    public Epic withEndDate(Date endDate) {
+        this.endDate = endDate;
+        return (this);
+    }
+
+    public Date getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Date createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public Date getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(Date updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+}

src/main/java/org/gitlab4j/api/models/EpicIssue.java

+
+package org.gitlab4j.api.models;
+
+import java.util.Map;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class EpicIssue extends Issue {
+
+    private Integer downvotes;
+    private Integer upvotes;
+
+    @JsonProperty("_links")
+    private Map<String, String> links;
+
+    private Boolean subscribed;
+    private Integer epicIssueId;
+    private Integer relativePosition;
+
+    public Integer getDownvotes() {
+        return downvotes;
+    }
+
+    public void setDownvotes(Integer downvotes) {
+        this.downvotes = downvotes;
+    }
+
+    public Integer getUpvotes() {
+        return upvotes;
+    }
+
+    public void setUpvotes(Integer upvotes) {
+        this.upvotes = upvotes;
+    }
+
+    public Map<String, String> getLinks() {
+        return links;
+    }
+
+    public void setLinks(Map<String, String> links) {
+        this.links = links;
+    }
+
+    @JsonIgnore
+    public String getLinkByName(String name) {
+        if (links == null || links.isEmpty()) {
+            return (null);
+        }
+
+        return (links.get(name));
+    }
+
+    public Boolean getSubscribed() {
+        return subscribed;
+    }
+
+    public void setSubscribed(Boolean subscribed) {
+        this.subscribed = subscribed;
+    }
+
+    public Integer getEpicIssueId() {
+        return epicIssueId;
+    }
+
+    public void setEpicIssueId(Integer epicIssueId) {
+        this.epicIssueId = epicIssueId;
+    }
+
+    public Integer getRelativePosition() {
+        return relativePosition;
+    }
+
+    public void setRelativePosition(Integer relativePosition) {
+        this.relativePosition = relativePosition;
+    }
+}

src/main/java/org/gitlab4j/api/models/Issue.java

@@ -15,6 +15,7 @@ import org.gitlab4j.api.Constants.IssueState;
 public class Issue {
 
     private Assignee assignee;
+    private List<Assignee> assignees;
     private Author author;
     private Boolean confidential;
     private Date createdAt;
@@ -33,6 +34,8 @@ public class Issue {
     private String title;
     private Integer userNotesCount;
     private String webUrl;
+    private Integer weight;
+    private Boolean discussionLocked;
     private TimeStats timeStats;
 
     public Assignee getAssignee() {
@@ -43,6 +46,14 @@ public class Issue {
         this.assignee = assignee;
     }
 
+    public List<Assignee> getAssignees() {
+        return assignees;
+    }
+
+    public void setAssignees(List<Assignee> assignees) {
+        this.assignees = assignees;
+    }
+
     public Author getAuthor() {
         return author;
     }
@@ -187,6 +198,22 @@ public class Issue {
         this.webUrl = webUrl;
     }
 
+    public Integer getWeight() {
+        return weight;
+    }
+
+    public void setWeight(Integer weight) {
+        this.weight = weight;
+    }
+
+    public Boolean getDiscussionLocked() {
+        return discussionLocked;
+    }
+
+    public void setDiscussionLocked(Boolean discussionLocked) {
+        this.discussionLocked = discussionLocked;
+    }
+
     public TimeStats getTimeStats() {
         return timeStats;
     }

src/test/java/org/gitlab4j/api/TestGitLabApiBeans.java

@@ -38,6 +38,8 @@ import org.gitlab4j.api.models.CommitPayload;
 import org.gitlab4j.api.models.CompareResults;
 import org.gitlab4j.api.models.DeployKey;
 import org.gitlab4j.api.models.Diff;
+import org.gitlab4j.api.models.Epic;
+import org.gitlab4j.api.models.EpicIssue;
 import org.gitlab4j.api.models.Event;
 import org.gitlab4j.api.models.FileUpload;
 import org.gitlab4j.api.models.Group;
@@ -169,6 +171,28 @@ public class TestGitLabApiBeans {
         }
     }
 
+    @Test
+    public void testEpic() {
+
+        try {
+            Epic epic = makeFakeApiCall(Epic.class, "epic");
+            assertTrue(compareJson(epic, "epic"));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Test
+    public void testEpicIssue() {
+
+        try {
+            EpicIssue epicIssue = makeFakeApiCall(EpicIssue.class, "epic-issue");
+            assertTrue(compareJson(epicIssue, "epic-issue"));
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
     @Test
     public void testEvent() {
 

src/test/resources/org/gitlab4j/api/epic-issue.json

+{
+  "id": 76,
+  "iid": 6,
+  "project_id": 8,
+  "title" : "Consequatur vero maxime deserunt laboriosam est voluptas dolorem.",
+  "description" : "Ratione dolores corrupti mollitia soluta quia.",
+  "state": "opened",
+  "created_at": "2017-11-15T13:39:24.670Z",
+  "updated_at": "2018-01-04T10:49:19.506Z",
+  "labels": [],
+  "milestone": {
+    "id": 38,
+    "iid": 3,
+    "project_id": 8,
+    "title": "v2.0",
+    "description": "In tempore culpa inventore quo accusantium.",
+    "state": "closed",
+    "created_at": "2017-11-15T13:39:13.825Z",
+    "updated_at": "2017-11-15T13:39:13.825Z"
+  },
+  "assignees": [{
+    "id": 7,
+    "name": "Pamella Huel",
+    "username": "arnita",
+    "state": "active",
+    "avatar_url": "http://www.gravatar.com/avatar/a2f5c6fcef64c9c69cb8779cb292be1b?s=80&d=identicon",
+    "web_url": "http://localhost:3001/arnita"
+  }],
+  "assignee": {
+    "id": 7,
+    "name": "Pamella Huel",
+    "username": "arnita",
+    "state": "active",
+    "avatar_url": "http://www.gravatar.com/avatar/a2f5c6fcef64c9c69cb8779cb292be1b?s=80&d=identicon",
+    "web_url": "http://localhost:3001/arnita"
+  },
+  "author": {
+    "id": 13,
+    "name": "Michell Johns",
+    "username": "chris_hahn",
+    "state": "active",
+    "avatar_url": "http://www.gravatar.com/avatar/30e3b2122ccd6b8e45e8e14a3ffb58fc?s=80&d=identicon",
+    "web_url": "http://localhost:3001/chris_hahn"
+  },
+  "user_notes_count": 8,
+  "upvotes": 0,
+  "downvotes": 0,
+  "confidential": false,
+  "weight": 9,
+  "discussion_locked": true,
+  "web_url": "http://localhost:3001/h5bp/html5-boilerplate/issues/6",
+  "time_stats": {
+    "time_estimate": 0,
+    "total_time_spent": 0
+  },
+  "_links":{
+    "self": "http://localhost:3001/api/v4/projects/8/issues/6",
+    "notes": "http://localhost:3001/api/v4/projects/8/issues/6/notes",
+    "award_emoji": "http://localhost:3001/api/v4/projects/8/issues/6/award_emoji",
+    "project": "http://localhost:3001/api/v4/projects/8"
+  },
+  "subscribed": true,
+  "epic_issue_id": 2,
+  "relative_position": 55
+}
\ No newline at end of file

src/test/resources/org/gitlab4j/api/epic.json

+{
+  "id": 30,
+  "iid": 5,
+  "group_id": 7,
+  "title": "Ea cupiditate dolores ut vero consequatur quasi veniam voluptatem et non.",
+  "description": "Molestias dolorem eos vitae expedita impedit necessitatibus quo voluptatum.",
+  "author":{
+    "id": 7,
+    "name": "Pamella Huel",
+    "username": "arnita",
+    "state": "active",
+    "avatar_url": "http://www.gravatar.com/avatar/a2f5c6fcef64c9c69cb8779cb292be1b?s=80&d=identicon",
+    "web_url": "http://localhost:3001/arnita"
+  },
+  "created_at": "2018-01-21T06:21:13.165Z",
+  "updated_at": "2018-01-22T12:41:41.166Z"
+}
\ No newline at end of file