Added support to fetch subgroups (#126).

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

@@ -104,6 +104,28 @@ public interface Constants {
         }
     }
 
+    /** Enum to use for ordering the results of getGroups() and getSubGroups(). */
+    public enum GroupOrderBy {
+
+        NAME, PATH;
+        private static JacksonJsonEnumHelper<GroupOrderBy> enumHelper = new JacksonJsonEnumHelper<>(GroupOrderBy.class);
+
+        @JsonCreator
+        public static GroupOrderBy 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 specifying the scope when calling getPipelines(). */
     public enum PipelineScope {
 

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

@@ -12,6 +12,7 @@ import org.gitlab4j.api.models.AccessLevel;
 import org.gitlab4j.api.models.Group;
 import org.gitlab4j.api.models.Member;
 import org.gitlab4j.api.models.Project;
+import org.gitlab4j.api.models.User;
 import org.gitlab4j.api.models.Visibility;
 
 /**
@@ -97,7 +98,7 @@ public class GroupApi extends AbstractApi {
      *
      * @param search the group name or path search criteria
      * @param itemsPerPage the number of Group instances that will be fetched per page
-     * @return a List containing matching Group instances
+     * @return a Pager containing matching Group instances
      * @throws GitLabApiException if any exception occurs
      */
     public Pager<Group> getGroups(String search, int itemsPerPage) throws GitLabApiException {
@@ -105,6 +106,124 @@ public class GroupApi extends AbstractApi {
         return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups"));
     }
 
+    /**
+     * Get a list 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
+     * @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, null, null, null, null, null, null, null, 1, getDefaultPerPage()));
+    }
+
+    /**
+     * Get a list 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 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 List&lt;Group&gt; of the matching subgroups
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 10.3.0
+     */
+    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()));
+    }
+
+    /**
+     * Get a list 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 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
+     * @param page the page to get
+     * @param perPage the number of Group instances per page
+     * @return a List&lt;Group&gt; of the matching subgroups
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 10.3.0
+     */
+    public List<Group> getSubGroups(Integer groupId, 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()
+                .withParam("skip_groups", skipGroups)
+                .withParam("all_available", allAvailable)
+                .withParam("search", search)
+                .withParam("order_by", orderBy)
+                .withParam("sort_order", sortOrder)
+                .withParam("statistics", statistics)
+                .withParam("owned", owned)
+                .withParam(PAGE_PARAM, page)
+                .withParam(PER_PAGE_PARAM, perPage);
+        Response response = get(Response.Status.OK, formData.asMap(), "groups", groupId, "subgroups");
+        return (response.readEntity(new GenericType<List<Group>>() {}));
+    }
+
+    /**
+     * 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>
+     *
+     * @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
+     * @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, 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)
+                .withParam("all_available", allAvailable)
+                .withParam("search", search)
+                .withParam("order_by", orderBy)
+                .withParam("sort_order", sortOrder)
+                .withParam("statistics", statistics)
+                .withParam("owned", owned);
+        return (new Pager<Group>(this, Group.class, itemsPerPage, formData.asMap(), "groups", groupId, "subgroups"));
+    }
+
     /**
      * Get a list of projects belonging to the specified group ID.
      *

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

@@ -11,11 +11,52 @@ import javax.xml.bind.annotation.XmlRootElement;
 @XmlAccessorType(XmlAccessType.FIELD)
 public class Group {
 
+    public class Statistics {
+        private Integer storageSize;
+        private Integer repositorySize;
+        private Integer lfsObjectsSize;
+        private Integer jobArtifactsSize;
+
+        public Integer getStorageSize() {
+            return storageSize;
+        }
+
+        public void setStorageSize(Integer storageSize) {
+            this.storageSize = storageSize;
+        }
+
+        public Integer getRepositorySize() {
+            return repositorySize;
+        }
+
+        public void setRepositorySize(Integer repositorySize) {
+            this.repositorySize = repositorySize;
+        }
+
+        public Integer getLfsObjectsSize() {
+            return lfsObjectsSize;
+        }
+
+        public void setLfsObjectsSize(Integer lfsObjectsSize) {
+            this.lfsObjectsSize = lfsObjectsSize;
+        }
+
+        public Integer getJobArtifactsSize() {
+            return jobArtifactsSize;
+        }
+
+        public void setJobArtifactsSize(Integer jobArtifactsSize) {
+            this.jobArtifactsSize = jobArtifactsSize;
+        }
+    }
+
+
     private Integer id;
     private String name;
     private String path;
     private String description;
     private Visibility visibility;
+    private Boolean lfsEnabled;
     private String avatarUrl;
     private String webUrl;
     private Boolean requestAccessEnabled;
@@ -23,6 +64,7 @@ public class Group {
     private String fullPath;
     private Integer parentId;
     private Integer sharedRunnersMinutesLimit;
+    private Statistics statistics;
     private List<Project> projects;
     private List<Project> sharedProjects;
 
@@ -66,6 +108,14 @@ public class Group {
         this.visibility = visibility;
     }
 
+    public Boolean getLfsEnabled() {
+        return lfsEnabled;
+    }
+
+    public void setLfsEnabled(Boolean lfsEnabled) {
+        this.lfsEnabled = lfsEnabled;
+    }
+
     public String getAvatarUrl() {
         return avatarUrl;
     }
@@ -122,6 +172,14 @@ public class Group {
         this.sharedRunnersMinutesLimit = sharedRunnersMinutesLimit;
     }
 
+    public Statistics getStatistics() {
+        return statistics;
+    }
+
+    public void setStatistics(Statistics statistics) {
+        this.statistics = statistics;
+    }
+
     public List<Project> getProjects() {
         return (projects);
     }

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

@@ -10,6 +10,12 @@
   "full_path": "twitter",
   "parent_id": 1234,
   "shared_runners_minutes_limit": 133,
+  "statistics": {
+    "storage_size" : 212,
+    "repository_size" : 33,
+    "lfs_objects_size" : 123,
+    "job_artifacts_size" : 57
+  },
   "projects": [
     {
       "id": 7,