Added Optional<> support (#127).

Author: gmessner

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

@@ -25,6 +25,7 @@
 
 import java.util.Date;
 import java.util.List;
+import java.util.Optional;
 
 import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.Response;
@@ -147,6 +148,23 @@ public Issue getIssue(Integer projectId, Integer issueId) throws GitLabApiExcept
         return (response.readEntity(Issue.class));
     }
 
+    /**
+     * Get a single project issue as an Optional instance.
+     *
+     * GET /projects/:id/issues/:issue_iid
+     *
+     * @param projectId the project ID to get the issue for
+     * @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) {
+        try {
+            return (Optional.ofNullable(getIssue(projectId, issueId)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
     /**
      * Create an issue for the project.
      *
@@ -462,13 +480,13 @@ public TimeStats resetSpentTime(Integer projectId, Integer issueIid) throws GitL
     }
 
     /**
-     * Get time tracking stats
+     * Get time tracking stats.
      * 
      * GET /projects/:id/issues/:issue_iid/time_stats
      * 
      * @param projectId the project ID that owns the issue
      * @param issueIid the internal ID of a project's issue
-     * @return a TimeSTats instance
+     * @return a TimeStats instance
      * @throws GitLabApiException if any exception occurs
      */
     public TimeStats getTimeTrackingStats(Integer projectId, Integer issueIid) throws GitLabApiException {
@@ -484,4 +502,21 @@ public TimeStats getTimeTrackingStats(Integer projectId, Integer issueIid) throw
         Response response = get(Response.Status.OK, new GitLabApiForm().asMap(), "projects", projectId, "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
+     *
+     * @param projectId the project ID that owns the issue
+     * @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) {
+        try {
+            return (Optional.ofNullable(getTimeTrackingStats(projectId, issueIid)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
 }

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

@@ -6,6 +6,7 @@
 import java.nio.file.Files;
 import java.nio.file.StandardCopyOption;
 import java.util.List;
+import java.util.Optional;
 
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
@@ -134,6 +135,23 @@ public Job getJob(int projectId, int jobId) throws GitLabApiException {
         return (response.readEntity(Job.class));
     }
 
+    /**
+     * Get single job in a project as an Optional instance.
+     *
+     * GET /projects/:id/jobs/:job_id
+     *
+     * @param projectId the project ID to get the specified job for
+     * @param jobId the job ID to get
+     * @return a single job for the specified project ID as an Optional intance
+     */
+    public Optional<Job> getOptionalJob(int projectId, int jobId) {
+        try {
+            return (Optional.ofNullable(getJob(projectId, jobId)));
+        } catch (GitLabApiException glae) {
+            return (GitLabApi.createOptionalFromException(glae));
+        }
+    }
+
     /**
      * Download the artifacts file from the given reference name and job provided the job finished successfully.
      * The file will be saved to the specified directory. If the file already exists in the directory it will