Get more information from gitlab (#186)

* Load forks of a project with Pager
* Load comments of a commit with Pager
* Load merge request changes
* Load merge request participants.
* Method to request repository contributors
* getMergeRequestChanges method needs list of diffs
* Fixed getFile method does not handle spaces in path correctly

Author: ISibboI

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

@@ -76,10 +76,23 @@ protected int getDefaultPerPage() {
     protected GitLabApiClient getApiClient() {
         return (gitLabApi.getApiClient());
     }
-
+    
+    /**
+     * Encode a string to be used as in-path argument for a gitlab api request.
+     * 
+     * Standard URL encoding changes spaces to plus signs, but for arguments that are part of the path,
+     * like the :file_path in a "Get raw file" request, gitlab expects spaces to be encoded with %20.
+     * 
+     * @param s the string to encode
+     * @return encoded version of s with spaces encoded as %2F
+     * @throws GitLabApiException if encoding throws an exception
+     */
     protected String urlEncode(String s) throws GitLabApiException {
         try {
             String encoded = URLEncoder.encode(s, "UTF-8");
+            // Since the encode method encodes plus signs as %2B,
+            // we can simply replace the encoded spaces with the correct encoding here 
+            encoded = encoded.replace("+", "%20");
             encoded = encoded.replace(".", "%2E");
             encoded = encoded.replace("-", "%2D");
             encoded = encoded.replace("_", "%5F");

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

@@ -302,6 +302,21 @@ public List<Comment> getComments(int projectId, String sha) throws GitLabApiExce
         Response response = get(Response.Status.OK, null, "projects", projectId, "repository", "commits", sha, "comments");
         return (response.readEntity(new GenericType<List<Comment>>() {}));
     }
+    
+    /**
+     * Get a Pager of the comments of a commit in a project.
+     *
+     * GET /projects/:id/repository/commits/:sha/comments
+     *
+     * @param projectId the project ID that the commit belongs to
+     * @param sha a commit hash or name of a branch or tag
+     * @param itemsPerPage the number of Comment instances that will be fetched per page
+     * @return a List of Comment instances for the specified project ID/sha pair
+     * @throws GitLabApiException GitLabApiException if any exception occurs during execution
+     */
+    public Pager<Comment> getComments(int projectId, String sha, int itemsPerPage) throws GitLabApiException {
+        return new Pager<Comment>(this, Comment.class, itemsPerPage, null, "projects", projectId, "repository", "commits", sha, "comments");
+    }
 
     /**
      * Add a comment to a commit.  In order to post a comment in a particular line of a particular file,

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

@@ -37,7 +37,7 @@ public String getApiNamespace() {
         }
     }
 
-    // Used to keep track of GitLabApiExceptions on calls that return Optionsl<?>
+    // Used to keep track of GitLabApiExceptions on calls that return Optional<?>
     private static final Map<Optional<?>, GitLabApiException> optionalExceptionMap =
             Collections.synchronizedMap(new WeakHashMap<Optional<?>, GitLabApiException>());
 

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

@@ -10,6 +10,7 @@
 import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.Commit;
 import org.gitlab4j.api.models.MergeRequest;
+import org.gitlab4j.api.models.Participant;
 
 /**
  * This class implements the client side API for the GitLab merge request calls.
@@ -577,4 +578,34 @@ public MergeRequest unapproveMergeRequest(Integer projectId, Integer mergeReques
         Response response = post(Response.Status.OK, (Form)null, "projects", projectId, "merge_requests", mergeRequestIid, "unapprove");
         return (response.readEntity(MergeRequest.class));
     }
+
+    /**
+     * Get merge request with changes information.
+     *
+     * GET /projects/:id/merge_requests/:merge_request_iid/changes
+     *
+     * @param projectId the project ID to get the merge requests for
+     * @param mergeRequestIid the IID of the merge request to get
+     * @return a merge request including its changes
+     * @throws GitLabApiException if any exception occurs
+     */
+    public MergeRequest getMergeRequestChanges(Integer projectId, Integer mergeRequestIid) throws GitLabApiException {
+        Response response = get(Response.Status.OK, null, "projects", projectId, "merge_requests", mergeRequestIid, "changes");
+        return (response.readEntity(MergeRequest.class));
+    }
+    
+    /**
+     * Get participants of merge request.
+     * 
+     * GET /projects/:id/merge_requests/:merge_request_iid/participants
+     * 
+     * @param projectId the project ID to get the merge requests for
+     * @param mergeRequestIid the IID of the merge request to get
+     * @param itemsPerPage the number of Participant instances that will be fetched per page
+     * @return all participants for the specified merge request
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Participant> getParticipants(Integer projectId, Integer mergeRequestIid, int itemsPerPage) throws GitLabApiException {
+        return new Pager<Participant>(this, Participant.class, itemsPerPage, null, "projects", projectId, "merge_requests", mergeRequestIid, "participants");
+    }
 }

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

@@ -1811,7 +1811,7 @@ public void deleteSnippet(Integer projectId, Integer snippetId) throws GitLabApi
         delete(Response.Status.NO_CONTENT, null, "projects", projectId, "snippets", snippetId);
     }
 
-    /*
+    /**
      * Get the raw project snippet as plain text.
      *
      * GET /projects/:id/snippets/:snippet_id/raw
@@ -1826,7 +1826,7 @@ public String getRawSnippetContent(Integer projectId, Integer snippetId) throws
         return (response.readEntity(String.class));
     }
 
-    /*
+    /**
      * Get the raw project snippet plain text as an Optional instance.
      *
      * GET /projects/:id/snippets/:snippet_id/raw
@@ -2054,4 +2054,18 @@ public void deletePushRules(Integer projectId) throws GitLabApiException {
 
         delete(Response.Status.OK, null, "projects", projectId, "push_rule");
     }
+    
+    /**
+     * Get a Pager of projects that were forked from the specified project.
+     * 
+     * GET /projects/:id/forks
+     * 
+     * @param projectId the ID of the project
+     * @param itemsPerPage the number of Project instances that will be fetched per page
+     * @return a Pager of projects
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Project> getForks(Integer projectId, int itemsPerPage) throws GitLabApiException {
+        return new Pager<Project>(this, Project.class, itemsPerPage, null, "projects", projectId, "forks");
+    }
 }

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

@@ -17,6 +17,7 @@
 import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.Branch;
 import org.gitlab4j.api.models.CompareResults;
+import org.gitlab4j.api.models.Contributor;
 import org.gitlab4j.api.models.Tag;
 import org.gitlab4j.api.models.TreeItem;
 import org.gitlab4j.api.utils.FileUtils;
@@ -498,4 +499,19 @@ public CompareResults compare(String projectPath, String from, String to) throws
         Response response = get(Response.Status.OK, formData.asMap(), "projects", projectPath, "repository", "compare");
         return (response.readEntity(CompareResults.class));
     }
+    
+    /**
+     * Get a Pager of contributors from a project.
+     *
+     * GET /projects/:id/repository/contributors
+     *
+     * @param projectId the project to get the list of contributors for
+     * @param itemsPerPage the number of Project instances that will be fetched per page
+     * @return the list of contributors for the specified project ID
+     *
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Pager<Contributor> getContributors(Integer projectId, int itemsPerPage) throws GitLabApiException {
+        return new Pager<Contributor>(this, Contributor.class, itemsPerPage, null, "projects", projectId, "repository", "contributors");
+    }
 }

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

@@ -0,0 +1,7 @@
+package org.gitlab4j.api.models;
+
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement
+public class Contributor extends AbstractUser {
+}

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

@@ -19,7 +19,7 @@ public class MergeRequest {
     private Integer approvalsBeforeMerge;
     private Assignee assignee;
     private Author author;
-    private Diff changes;
+    private List<Diff> changes;
     private Date createdAt;
     private String description;
     private Integer downvotes;
@@ -80,11 +80,11 @@ public void setAuthor(Author author) {
         this.author = author;
     }
 
-    public Diff getChanges() {
+    public List<Diff> getChanges() {
         return changes;
     }
 
-    public void setChanges(Diff changes) {
+    public void setChanges(List<Diff> changes) {
         this.changes = changes;
     }
 

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

@@ -0,0 +1,7 @@
+package org.gitlab4j.api.models;
+
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement
+public class Participant extends AbstractUser {
+}