Added support for group and project variables (#330).

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

@@ -13,9 +13,10 @@ import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.AccessLevel;
 import org.gitlab4j.api.models.Group;
 import org.gitlab4j.api.models.GroupFilter;
+import org.gitlab4j.api.models.GroupProjectsFilter;
 import org.gitlab4j.api.models.Member;
 import org.gitlab4j.api.models.Project;
-import org.gitlab4j.api.models.GroupProjectsFilter;
+import org.gitlab4j.api.models.Variable;
 import org.gitlab4j.api.models.Visibility;
 
 /**
@@ -175,13 +176,13 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @return a List&lt;Group&gt; containing the group's sub-groups
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 10.3.0
      */
-    public List<Group> getSubGroups(Integer groupId) throws GitLabApiException {
-        return (getSubGroups(groupId, getDefaultPerPage()).all());
+    public List<Group> getSubGroups(Object groupIdOrPath) throws GitLabApiException {
+        return (getSubGroups(groupIdOrPath, getDefaultPerPage()).all());
     }
 
     /**
@@ -189,14 +190,14 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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"));
+    public Pager<Group> getSubGroups(Object groupIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Group>(this, Group.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "subgroups"));
     }
 
     /**
@@ -204,13 +205,13 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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());
+    public Stream<Group> getSubGroupsStream(Object groupIdOrPath) throws GitLabApiException {
+        return (getSubGroups(groupIdOrPath, getDefaultPerPage()).stream());
     }
 
     /**
@@ -218,7 +219,7 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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
@@ -230,9 +231,9 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 10.3.0
      */
-    public List<Group> getSubGroups(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
+    public List<Group> getSubGroups(Object groupIdOrPath, 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()).all());
+        return (getSubGroups(groupIdOrPath, skipGroups, allAvailable, search, orderBy, sortOrder, statistics, owned, getDefaultPerPage()).all());
     }
 
     /**
@@ -240,7 +241,7 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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
@@ -254,7 +255,7 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 10.3.0
      */
-    public List<Group> getSubGroups(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
+    public List<Group> getSubGroups(Object groupIdOrPath, List<Integer> skipGroups, Boolean allAvailable, String search,
             GroupOrderBy orderBy, SortOrder sortOrder, Boolean statistics, Boolean owned,  int page, int perPage)
             throws GitLabApiException {
         Form formData = new GitLabApiForm()
@@ -267,7 +268,7 @@ public class GroupApi extends AbstractApi {
                 .withParam("owned", owned)
                 .withParam(PAGE_PARAM, page)
                 .withParam(PER_PAGE_PARAM, perPage);
-        Response response = get(Response.Status.OK, formData.asMap(), "groups", groupId, "subgroups");
+        Response response = get(Response.Status.OK, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "subgroups");
         return (response.readEntity(new GenericType<List<Group>>() {}));
     }
 
@@ -276,7 +277,7 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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
@@ -289,7 +290,7 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 10.3.0
      */
-    public Pager<Group> getSubGroups(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
+    public Pager<Group> getSubGroups(Object groupIdOrPath, List<Integer> skipGroups, Boolean allAvailable, String search,
             GroupOrderBy orderBy, SortOrder sortOrder, Boolean statistics, Boolean owned, int itemsPerPage) throws GitLabApiException {
         Form formData = new GitLabApiForm()
                 .withParam("skip_groups", skipGroups)
@@ -299,7 +300,7 @@ public class GroupApi extends AbstractApi {
                 .withParam("sort_order", sortOrder)
                 .withParam("statistics", statistics)
                 .withParam("owned", owned);
-        return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups", groupId, "subgroups"));
+        return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups", getGroupIdOrPath(groupIdOrPath), "subgroups"));
     }
 
     /**
@@ -307,7 +308,7 @@ public class GroupApi extends AbstractApi {
      *
      * <pre><code>GitLab Endpoint: GET /groups/:id/subgroups</code></pre>
      *
-     * @param groupId the group ID to get the sub groups for
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
      * @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
@@ -319,9 +320,9 @@ public class GroupApi extends AbstractApi {
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 10.3.0
      */
-    public Stream<Group> getSubGroupsStream(Integer groupId, List<Integer> skipGroups, Boolean allAvailable, String search,
+    public Stream<Group> getSubGroupsStream(Object groupIdOrPath, 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());
+        return (getSubGroups(groupIdOrPath, skipGroups, allAvailable, search, orderBy, sortOrder, statistics, owned, getDefaultPerPage()).stream());
     }
 
     /**
@@ -988,4 +989,148 @@ public class GroupApi extends AbstractApi {
 
         delete(Response.Status.OK, null, "groups", getGroupIdOrPath(groupIdOrPath), "ldap_group_links", provider, cn);
     }
+
+    /**
+     * Get list of a group’s variables.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables</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 variables belonging to the specified group
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Variable> getVariables(Object groupIdOrPath) throws GitLabApiException {
+        return (getVariables(groupIdOrPath, getDefaultPerPage()).all());
+    }
+
+    /**
+     * Get a list of variables for the specified group in the specified page range.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables</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 Variable instances per page
+     * @return a list of variables belonging to the specified group in the specified page range
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Variable> getVariables(Object groupIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "groups", getGroupIdOrPath(groupIdOrPath), "variables");
+        return (response.readEntity(new GenericType<List<Variable>>() {}));
+    }
+
+    /**
+     * Get a Pager of variables belonging to the specified group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables</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 Variable instances that will be fetched per page
+     * @return a Pager of variables belonging to the specified group
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Variable> getVariables(Object groupIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Variable>(this, Variable.class, itemsPerPage, null, "groups", getGroupIdOrPath(groupIdOrPath), "variables"));
+    }
+
+    /**
+     * Get a Stream of variables belonging to the specified group.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables</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 variables belonging to the specified group
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Variable> getVariablesStream(Object groupIdOrPath) throws GitLabApiException {
+        return (getVariables(groupIdOrPath, getDefaultPerPage()).stream());
+    }
+
+    /**
+     * Get the details of a group variable.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables/:key</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param key the key of an existing variable, required
+     * @return the Variable instance for the specified group variable
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Variable getVariable(Object groupIdOrPath, String key) throws GitLabApiException {
+      Response response = get(Response.Status.OK, null, "groups", getGroupIdOrPath(groupIdOrPath), "variables", key);
+      return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Get the details of a group variable as an Optional instance.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables/:key</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path
+     * @param key the key of an existing variable, required
+     * @return the Variable for the specified group variable as an Optional instance
+     */
+    public Optional<Variable> getOptionalVariable(Object groupIdOrPath, String key) {
+        try {
+            return (Optional.ofNullable(getVariable(groupIdOrPath, key)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
+    /**
+     * Create a new group variable.
+     *
+     * <pre><code>GitLab Endpoint: POST /groups/:id/variables</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
+     * @param key the key of a variable; must have no more than 255 characters; only A-Z, a-z, 0-9, and _ are allowed, required
+     * @param value the value for the variable, required
+     * @param isProtected whether the variable is protected, optional
+     * @return a Variable instance with the newly created variable
+     * @throws GitLabApiException if any exception occurs during execution
+     */
+    public Variable createVariable(Object groupIdOrPath, String key, String value, Boolean isProtected) throws GitLabApiException {
+
+        GitLabApiForm formData = new GitLabApiForm()
+                .withParam("key", key, true)
+                .withParam("value", value, true)
+                .withParam("protected", isProtected);
+        Response response = post(Response.Status.CREATED, formData, "groups", getGroupIdOrPath(groupIdOrPath), "variables");
+        return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Update a group variable.
+     *
+     * <pre><code>GitLab Endpoint: PUT /groups/:id/variables/:key</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
+     * @param key the key of an existing variable, required
+     * @param value the value for the variable, required
+     * @param isProtected whether the variable is protected, optional
+     * @return a Variable instance with the updated variable
+     * @throws GitLabApiException if any exception occurs during execution
+     */
+    public Variable updateVariable(Object groupIdOrPath, String key, String value, Boolean isProtected) throws GitLabApiException {
+
+        GitLabApiForm formData = new GitLabApiForm()
+                .withParam("value", value, true)
+                .withParam("protected", isProtected);
+        Response response = putWithFormData(Response.Status.CREATED, formData, "groups", getGroupIdOrPath(groupIdOrPath), "variables", key);
+        return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Deletes a group variable.
+     *
+     * <pre><code>DELETE /groups/:id/variables/:key</code></pre>
+     *
+     * @param groupIdOrPath the group ID, path of the group, or a Group instance holding the group ID or path, required
+     * @param key the key of an existing variable, required
+     * @throws GitLabApiException if any exception occurs
+     */
+    public void deleteVariable(Object groupIdOrPath, String key) throws GitLabApiException {
+        delete(Response.Status.NO_CONTENT, null, "groups", getGroupIdOrPath(groupIdOrPath), "variables", key);
+    }
 }

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

@@ -49,6 +49,7 @@ import org.gitlab4j.api.models.ProjectHook;
 import org.gitlab4j.api.models.ProjectUser;
 import org.gitlab4j.api.models.PushRules;
 import org.gitlab4j.api.models.Snippet;
+import org.gitlab4j.api.models.Variable;
 import org.gitlab4j.api.models.Visibility;
 
 /**
@@ -2395,4 +2396,152 @@ public class ProjectApi extends AbstractApi implements Constants {
         Response response = putUpload(Response.Status.OK, "avatar", avatarFile, "projects", getProjectIdOrPath(projectIdOrPath));
         return (response.readEntity(Project.class));
     }
+
+    /**
+     * Get list of a project's variables.
+     *
+     * <pre><code>GitLab Endpoint: GET /groups/:id/variables</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @return a list of variables belonging to the specified project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Variable> getVariables(Object projectIdOrPath) throws GitLabApiException {
+        return (getVariables(projectIdOrPath, getDefaultPerPage()).all());
+    }
+
+    /**
+     * Get a list of variables for the specified project in the specified page range.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/variables</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param page the page to get
+     * @param perPage the number of Variable instances per page
+     * @return a list of variables belonging to the specified project in the specified page range
+     * @throws GitLabApiException if any exception occurs
+     */
+    public List<Variable> getVariables(Object projectIdOrPath, int page, int perPage) throws GitLabApiException {
+        Response response = get(Response.Status.OK, getPageQueryParams(page, perPage), "projects", getProjectIdOrPath(projectIdOrPath), "variables");
+        return (response.readEntity(new GenericType<List<Variable>>() {}));
+    }
+
+    /**
+     * Get a Pager of variables belonging to the specified project.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/variables</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param itemsPerPage the number of Variable instances that will be fetched per page
+     * @return a Pager of variables belonging to the specified project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Variable> getVariables(Object projectIdOrPath, int itemsPerPage) throws GitLabApiException {
+        return (new Pager<Variable>(this, Variable.class, itemsPerPage, null, "projects", getProjectIdOrPath(projectIdOrPath), "variables"));
+    }
+
+    /**
+     * Get a Stream of variables belonging to the specified project.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/variables</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @return a Stream of variables belonging to the specified project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Stream<Variable> getVariablesStream(Object projectIdOrPath) throws GitLabApiException {
+        return (getVariables(projectIdOrPath, getDefaultPerPage()).stream());
+    }
+
+    /**
+     * Get the details of a project variable.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/variables/:key</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param key the key of an existing variable, required
+     * @return the Variable instance for the specified variable
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Variable getVariable(Object projectIdOrPath, String key) throws GitLabApiException {
+      Response response = get(Response.Status.OK, null, "projects", getProjectIdOrPath(projectIdOrPath), "variables", key);
+      return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Get the details of a variable as an Optional instance.
+     *
+     * <pre><code>GitLab Endpoint: GET /projects/:id/variables/:key</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param key the key of an existing variable, required
+     * @return the Variable for the specified variable as an Optional instance
+     */
+    public Optional<Variable> getOptionalVariable(Object projectIdOrPath, String key) {
+        try {
+            return (Optional.ofNullable(getVariable(projectIdOrPath, key)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
+    /**
+     * Create a new project variable.
+     *
+     * <pre><code>GitLab Endpoint: POST /projects/:id/variables</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param key the key of a variable; must have no more than 255 characters; only A-Z, a-z, 0-9, and _ are allowed, required
+     * @param value the value for the variable, required
+     * @param isProtected whether the variable is protected, optional
+     * @param environmentScope the environment_scope of the variable, optional
+     * @return a Variable instance with the newly created variable
+     * @throws GitLabApiException if any exception occurs during execution
+     */
+    public Variable createVariable(Object projectIdOrPath, String key, String value, Boolean isProtected, String environmentScope) throws GitLabApiException {
+
+        GitLabApiForm formData = new GitLabApiForm()
+                .withParam("key", key, true)
+                .withParam("value", value, true)
+                .withParam("protected", isProtected)
+                .withParam("environment_scope",  environmentScope);
+        Response response = post(Response.Status.CREATED, formData, "projects", getProjectIdOrPath(projectIdOrPath), "variables");
+        return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Update a project variable.
+     *
+     * <pre><code>GitLab Endpoint: PUT /projects/:id/variables/:key</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param key the key of an existing variable, required
+     * @param value the value for the variable, required
+     * @param isProtected whether the variable is protected, optional
+     * @param environmentScope the environment_scope of the variable, optional
+     * @return a Variable instance with the updated variable
+     * @throws GitLabApiException if any exception occurs during execution
+     */
+    public Variable updateVariable(Object projectIdOrPath, String key, String value, Boolean isProtected, String environmentScope) throws GitLabApiException {
+
+        GitLabApiForm formData = new GitLabApiForm()
+                .withParam("value", value, true)
+                .withParam("protected", isProtected)
+                .withParam("environment_scope",  environmentScope);
+        Response response = putWithFormData(Response.Status.OK, formData, "projects", getProjectIdOrPath(projectIdOrPath), "variables", key);
+        return (response.readEntity(Variable.class));
+    }
+
+    /**
+     * Deletes a project variable.
+     *
+     * <pre><code>DELETE /projects/:id/variables/:key</code></pre>
+     *
+     * @param projectIdOrPath projectIdOrPath the project in the form of an Integer(ID), String(path), or Project instance, required
+     * @param key the key of an existing variable, required
+     * @throws GitLabApiException if any exception occurs
+     */
+    public void deleteVariable(Object projectIdOrPath, String key) throws GitLabApiException {
+        delete(Response.Status.NO_CONTENT, null, "projects", getProjectIdOrPath(projectIdOrPath), "variables", key);
+    }
 }

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

@@ -4,12 +4,19 @@ import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlRootElement;
 
+import org.gitlab4j.api.utils.JacksonJson;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 @XmlRootElement
 @XmlAccessorType(XmlAccessType.FIELD)
 public class Variable {
 
     private String key;
     private String value;
+    @JsonProperty("protected")
+    private Boolean isProtected;
+    private String environmentScope;
 
     public String getKey() {
         return key;
@@ -26,4 +33,25 @@ public class Variable {
     public void setValue(String value) {
         this.value = value;
     }
+
+    public Boolean getProtected() {
+        return isProtected;
+    }
+
+    public void setProtected(Boolean isProtected) {
+        this.isProtected = isProtected;
+    }
+
+    public String getEnvironmentScope() {
+        return environmentScope;
+    }
+
+    public void setEnvironmentScope(String environmentScope) {
+        this.environmentScope = environmentScope;
+    }
+
+    @Override
+    public String toString() {
+        return (JacksonJson.toJsonString(this));
+    }
 }

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

@@ -79,6 +79,7 @@ import org.gitlab4j.api.models.SystemHook;
 import org.gitlab4j.api.models.Tag;
 import org.gitlab4j.api.models.TreeItem;
 import org.gitlab4j.api.models.User;
+import org.gitlab4j.api.models.Variable;
 import org.gitlab4j.api.services.JiraService;
 import org.gitlab4j.api.services.SlackService;
 import org.gitlab4j.api.systemhooks.ProjectSystemHookEvent;
@@ -243,6 +244,12 @@ public class TestGitLabApiBeans {
         assertTrue(compareJson(pipelineSchedule, "pipeline-schedule.json"));
     }
 
+    @Test
+    public void testProjectVariables() throws Exception {
+        List<Variable> variables = unmarshalResourceList(Variable.class, "project-variables.json");
+        assertTrue(compareJson(variables, "project-variables.json"));
+    }
+
     @Test
     public void testJob() throws Exception {
         Job job = unmarshalResource(Job.class, "job.json");

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

@@ -26,6 +26,7 @@ package org.gitlab4j.api;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
 
@@ -33,6 +34,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.stream.Stream;
 
 import javax.ws.rs.core.Response;
 
@@ -40,6 +42,7 @@ import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.AccessLevel;
 import org.gitlab4j.api.models.Group;
 import org.gitlab4j.api.models.Project;
+import org.gitlab4j.api.models.Variable;
 import org.gitlab4j.api.models.Visibility;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -87,6 +90,7 @@ public class TestProjectApi {
     private static final String TEST_PROJECT_NAME_2 = "test-gitlab4j-create-project-2";
     private static final String TEST_PROJECT_NAME_UPDATE = "test-gitlab4j-create-project-update";
     private static final String TEST_XFER_PROJECT_NAME = "test-gitlab4j-xfer-project";
+    private static final String TEST_VARIABLE_KEY_PREFIX = "TEST_VARIABLE_KEY_";
     private static GitLabApi gitLabApi;
 
     public TestProjectApi() {
@@ -150,7 +154,18 @@ public class TestProjectApi {
                     Project project = gitLabApi.getProjectApi().getProject(TEST_NAMESPACE, TEST_PROJECT_NAME);
                     List<Group> groups = gitLabApi.getGroupApi().getGroups(TEST_GROUP);
                     gitLabApi.getProjectApi().unshareProject(project.getId(), groups.get(0).getId());
-                } catch (GitLabApiException ignore) {}
+
+                    List<Variable> variables = gitLabApi.getProjectApi().getVariables(project);
+                    if (variables != null) {
+
+                        for (Variable variable : variables) {
+                            if (variable.getKey().startsWith(TEST_VARIABLE_KEY_PREFIX)) {
+                                gitLabApi.getProjectApi().deleteVariable(project, variable.getKey());
+                            }
+                        }
+                    }
+                } catch (GitLabApiException ignore) {
+                }
             }
 
             if (TEST_GROUP != null && TEST_GROUP_PROJECT != null) {
@@ -589,4 +604,44 @@ public class TestProjectApi {
         Project transferedProject = gitLabApi.getProjectApi().transferProject(projectToTransfer, TEST_XFER_NAMESPACE);
         assertNotNull(transferedProject);
     }
+
+    @Test
+    public void testVariables() throws GitLabApiException {
+
+        Project project = gitLabApi.getProjectApi().getProject(TEST_NAMESPACE, TEST_PROJECT_NAME);
+        assertNotNull(project);
+
+        String key = TEST_VARIABLE_KEY_PREFIX + TestUtils.getRandomInt() + "_" +  TestUtils.getRandomInt();
+        String value = "TEST_VARIABLE_VALUE_" + TestUtils.getRandomInt() + "_" +  TestUtils.getRandomInt();
+        Variable variable = gitLabApi.getProjectApi().createVariable(project, key, value, null, null);
+
+        assertNotNull(variable);
+        assertEquals(key, variable.getKey());
+        assertEquals(value, variable.getValue());
+
+        Stream<Variable> variables = gitLabApi.getProjectApi().getVariablesStream(project);
+        assertNotNull(variables);
+
+        Variable matchingVariable = variables.filter(v -> v.getKey().equals(key)).findAny().orElse(null);
+        assertNotNull(matchingVariable);
+        assertEquals(key, matchingVariable.getKey());
+        assertEquals(value, matchingVariable.getValue());
+        assertFalse(matchingVariable.getProtected());
+        assertNull(matchingVariable.getEnvironmentScope());
+
+        gitLabApi.getProjectApi().updateVariable(project, key, "NONE", true, "DEV");
+        variable = gitLabApi.getProjectApi().getVariable(project, key);
+
+        assertNotNull(variable);
+        assertEquals(key, variable.getKey());
+        assertEquals("NONE", variable.getValue());
+        assertTrue(variable.getProtected());
+
+        gitLabApi.getProjectApi().deleteVariable(project, key);
+        variables = gitLabApi.getProjectApi().getVariablesStream(project);
+        assertNotNull(variables);
+
+        matchingVariable = variables.filter(v -> v.getKey().equals(key)).findAny().orElse(null);
+        assertNull(matchingVariable);
+    }
 }

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

@@ -62,4 +62,23 @@ public class TestUtils {
     public static final String getProperty(String key) {
         return (testProperties.getProperty(key));
     }
+
+    /**
+     * Get a random integer between 1 and the specified value (inclusive).
+     *
+     * @param maxValue the maximum value to return
+     * @return a random integer between 1 and the specified value (inclusive)
+     */
+    public static final int getRandomInt(int maxValue) {
+        return ((int)(Math.random() * maxValue + 1));
+    }
+
+    /**
+     * Get a random integer between 1 and Integer.MAX_VALUE (inclusive).
+     *
+     * @return a random integer between 1 and Integer.MAX_VALUE (inclusive)
+     */
+    public static final int getRandomInt() {
+        return (getRandomInt(Integer.MAX_VALUE));
+    }
 }

src/test/resources/org/gitlab4j/api/project-variables.json

+[
+    {
+        "key": "TEST_VARIABLE_1",
+        "value": "TEST_1",
+        "protected": true,
+    	"environment_scope": "*"
+    },
+    {
+        "key": "TEST_VARIABLE_2",
+        "value": "TEST_2",
+        "protected": false
+    },
+    {
+        "key": "TEST_VARIABLE_3",
+        "value": "TEST_3",
+    	"environment_scope": "DEV"
+    },
+    {
+        "key": "TEST_VARIABLE_4",
+        "value": "TEST_4"
+    }
+]
\ No newline at end of file