Added method to upload user avatar (#314).

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

@@ -3,6 +3,7 @@ package org.gitlab4j.api;
 import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.CustomAttribute;
 import org.gitlab4j.api.models.ImpersonationToken;
+import org.gitlab4j.api.models.Project;
 import org.gitlab4j.api.models.ImpersonationToken.Scope;
 import org.gitlab4j.api.models.SshKey;
 import org.gitlab4j.api.models.User;
@@ -10,6 +11,8 @@ import org.gitlab4j.api.models.User;
 import javax.ws.rs.core.Form;
 import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.Response;
+
+import java.io.File;
 import java.util.Date;
 import java.util.List;
 import java.util.Objects;
@@ -995,4 +998,19 @@ public class UserApi extends AbstractApi {
         GitLabApiForm formData = new GitLabApiForm();
         return (customAttributesEnabled ? formData.withParam("with_custom_attributes", true) : formData);
     }
+
+    /**
+     * Uploads and sets the user's avatar for the specified user.
+     *
+     * <pre><code>PUT /users/:id</code></pre>
+     *
+     * @param userIdOrUsername the user in the form of an Integer(ID), String(username), or User instance
+     * @param avatarFile the File instance of the avatar file to upload
+     * @return the updated User instance
+     * @throws GitLabApiException if any exception occurs
+     */
+    public User setUserAvatar(final Object userIdOrUsername, File avatarFile) throws GitLabApiException {
+        Response response = putUpload(Response.Status.OK, "avatar", avatarFile,  "users", getUserIdOrUsername(userIdOrUsername));
+        return (response.readEntity(User.class));
+    }
 }

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

@@ -9,6 +9,7 @@ import java.util.Map;
 
 import org.gitlab4j.api.GitLabApi.ApiVersion;
 import org.gitlab4j.api.models.Project;
+import org.gitlab4j.api.models.User;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.FixMethodOrder;
@@ -45,7 +46,8 @@ public class TestAvatarUpload {
         TEST_PROXY_USERNAME = TestUtils.getProperty("TEST_PROXY_USERNAME");
         TEST_PROXY_PASSWORD = TestUtils.getProperty("TEST_PROXY_PASSWORD");
     }
-
+    
+    
     private static final String AVATAR_FILENAME = "avatar.png";
 
     private static GitLabApi gitLabApi;
@@ -116,4 +118,16 @@ public class TestAvatarUpload {
         assertNotNull(updatedProject);
         assertTrue(updatedProject.getAvatarUrl().endsWith(AVATAR_FILENAME));
     }
+
+    @Test
+    public void testSetUserAvatar() throws GitLabApiException {
+
+        User user = gitLabApi.getUserApi().getCurrentUser();
+        assertNotNull(user);
+
+        File avatarFile = new File("src/test/resources/org/gitlab4j/api", AVATAR_FILENAME);
+        User updatedUser = gitLabApi.getUserApi().setUserAvatar(user, avatarFile);
+        assertNotNull(updatedUser);
+        assertTrue(updatedUser.getAvatarUrl().endsWith(AVATAR_FILENAME));
+    }
 }