Facebook4J

- An 'Unofficial' library for the Facebook API in Java -

Code Examples

Getting Facebook Instance

At first it is necessary to acquire Facebook instance to use Facebook4J.
You can get Facebook instance in FacebookFactory.getInstance().

Facebook facebook = new FacebookFactory().getInstance();

If App ID / App Secret / access token / access permission are listed in facebook4j.properties then, they are set in Facebook instance given back.
See Configuration | Facebook4J - A Java library for the Facebook Graph API for the detail.
When they are not listed, it is setable later as follows:

facebook.setOAuthAppId(appId, appSecret);
facebook.setOAuthPermissions(commaSeparetedPermissions);
facebook.setOAuthAccessToken(new AccessToken(accessToken, null));

OAuth support

Getting User Access Token

It is possible to authenticate users using Facebook accounts with your web application.
An example implementation is available at https://github.com/roundrop/facebook4j-oauth-example .

Getting App Access Token

You can get App Access Token via Facebook.getOAuthAppAccessToken() method.

facebook.getOAuthAppAccessToken();

Getting Page Access Token

You can get Page Access Token as below:

ResponseList<Account> accounts = facebook.getAccounts();
Account yourPageAccount = accounts.get(0);  // if index 0 is your page account.
String pageAccessToken = yourPageAccount.getAccessToken();

Getting Device Access Token

With Facebook Login for Devices people can easily and safely log into your apps and services with their Facebook account on devices with limited input or display capabilities.
(See Facebook’s Documentation: Facebook Login for Devices )
An example implementation is available at https://github.com/roundrop/facebook4j-oauth-example .

Extending expiration of an Access Token

(See Facebook’s Documentation: Expiration and Extension of Access Tokens )
You can extend Access Token’s expiration as below:

String shortLivedToken = "your-short-lived-token";
AccessToken extendedToken = facebook.extendTokenExpiration(shortLivedToken);

Publishing a message

You can publish a message via Facebook.postStatusMessage() method.

facebook.postStatusMessage("Hello World from Facebook4J.");

You can publish a link via Facebook.postFeed() method.

PostUpdate post = new PostUpdate(new URL("https://facebook4j.github.io"))
                    .picture(new URL("https://facebook4j.github.io/images/hero.png"))
                    .name("Facebook4J - A Java library for the Facebook Graph API")
                    .caption("facebook4j.org")
                    .description("Facebook4J is a Java library for the Facebook Graph API.");
facebook.postFeed(post);

Facebook.postLink() method is simple way to post.

facebook.postLink(new URL("https://facebook4j.github.io"));
facebook.postLink(new URL("https://facebook4j.github.io"), "A Java library for the Facebook Graph API");

Getting News Feed

Facebook.getHome() returns a List of user’s latest News Feed.

ResponseList<Post> feed = facebook.getHome();

Like

You can like a Post, Photo, … via Facebook.like****() methods.

facebook.likePost(postId);

Also, You can unlike a Post, Photo, … via Facebook.unlike****() methods.

facebook.unlikePost(postId);

Publising a comment

You can comment a Post, Photo, … via Facebook.comment****() methods.

facebook.commentPhoto(photoId, "It's a nice photo!");

You can search for Posts, Users, … via Facebook.search****() methods.

Search for public Posts

ResponseList<Post> results = facebook.searchPosts("watermelon");

Search for Users

ResponseList<User> results = facebook.searchUsers("mark");

Search for Events

ResponseList<Event> results = facebook.searchEvents("conference");

Search for Groups

ResponseList<Group> results = facebook.searchGroups("programming");

Search for Places

// Search by name
ResponseList<Place> results = facebook.searchPlaces("coffee");

// You can narrow your search to a specific location and distance
GeoLocation center = new GeoLocation(37.76, -122.427);
int distance = 1000;
ResponseList<Place> searchPlaces("coffee", center, distance);

Search for Checkins

// you or your friend's latest checkins, or checkins where you or your friends have been tagged
ResponseList<Checkin> results = facebook.searchCheckins();

Search for Locations

// To search for objects near a geographical location
GeoLocation center = new GeoLocation(37.76, -122.427);
int distance = 1000;
ResponseList<Location> searchLocations(center, distance);

// To search for objects at a particular place
String placeId = "166793820034304";
ResponseList<Location> locations = facebookBestFriend1.searchLocations(placeId);

Executing FQL

You can execute FQL via Facebook.executeFQL() method.
Also you can execute multiple FQL in one call via Facebook.executeMultiFQL() method.

// Single FQL
String query = "SELECT uid2 FROM friend WHERE uid1=me()";
JSONArray jsonArray = facebook.executeFQL(query);
for (int i = 0; i < jsonArray.length(); i++) {
    JSONObject jsonObject = jsonArray.getJSONObject(i);
    System.out.println(jsonObject.get("uid2"));
}

// Multiple FQL
Map<String, String> queries = new HashMap<String, String>();
queries.put("all friends", "SELECT uid2 FROM friend WHERE uid1=me()");
queries.put("my name", "SELECT name FROM user WHERE uid=me()");
Map<String, JSONArray> result = facebook.executeMultiFQL(queries);
JSONArray allFriendsJSONArray = result.get("all friends");
for (int i = 0; i < allFriendsJSONArray.length(); i++) {
    JSONObject jsonObject = allFriendsJSONArray.getJSONObject(i);
    System.out.println(jsonObject.get("uid2"));
}
JSONArray myNameJSONArray = result.get("my name");
System.out.println(myNameJSONArray.getJSONObject(0).get("name"));

Executing Batch Requests

You can execute Batch Requests via Facebook.executeBatch() method.

// Executing "me" and "me/friends?limit=50" endpoints
BatchRequests<BatchRequest> batch = new BatchRequests<BatchRequest>();
batch.add(new BatchRequest(RequestMethod.GET, "me"));
batch.add(new BatchRequest(RequestMethod.GET, "me/friends?limit=50"));
List<BatchResponse> results = facebook.executeBatch(batch);

BatchResponse result1 = results.get(0);
BatchResponse result2 = results.get(1);

// You can get http status code or headers
int statusCode1 = result1.getStatusCode();
String contentType = result1.getResponseHeader("Content-Type");

// You can get body content via as****() method
String jsonString = result1.asString();
JSONObject jsonObject = result1.asJSONObject();
ResponseList<JSONObject> responseList = result2.asResponseList();

// You can map json to java object using DataObjectFactory#create****()
User user = DataObjectFactory.createUser(jsonString);
Friend friend1 = DataObjectFactory.createFriend(responseList.get(0).toString());
Friend friend2 = DataObjectFactory.createFriend(responseList.get(1).toString());
:

You can attach a binary data to batch request as follows:

BatchRequests<BatchRequest> batch = new BatchRequests<BatchRequest>();
Media file = new Media(new File("...image.png"));
BatchAttachment attachment = new BatchAttachment("file", file);
batch.add(new BatchRequest(RequestMethod.POST, "me/photos")
              .body("message=My photo")
              .attachedFile(attachment));

Executing Raw API (setting the endpoint on your own)

You can execute the API endpoint that you want to run via Facebook.call**() method.

// GET
RawAPIResponse res = facebook.callGetAPI("me");
JSONObject jsonObject = actual.asJSONObject();
String id = jsonObject.getString("id");

// POST
Map<String, String> params = new HashMap<String, String>();
params.put("message", "hello");
RawAPIResponse res = facebook.callPostAPI("me/feed", params);

// DELETE
RawAPIResponse res = facebook.callDeleteAPI("123456/likes");
if (res.isBoolean()) {
  System.out.println(res.asBoolean());
}

You can execute the API endpoint that is not supported by Facebook4J via Facebook.call**() method.


Reading options

You can set various reading options to the method that Reading object includes in arguments.

Selecting specific fields

You can choose the fields you want returned via Reading.fields(“fieldName1,fieldName2,…”) .

// Getting user's email address only
User user = facebook1.getUser(id1.getId(), new Reading().fields("email"));

limit/offset

// Getting 1st-10th results
ResponseList<Post> results = facebook.searchPosts("watermelon", new Reading().limit(10));

// Getting 11th-20th results
ResponseList<Post> results = facebook.searchPosts("watermelon", new Reading().limit(10).offset(10));

until/since

until/since values can be a unix timestamp or any date accepted by PHP’s strtotime format.

ResponseList<Post> results = facebook.searchPosts("watermelon", new Reading().until("yesterday"));

Pagination

You can get next/previous page with Paging object in results via Facebook.fetchNext() / Facebook.fetchPrevious() methods.

ResponseList<Option> page1 = facebook.getQuestionOptions(questionId);

// Getting Next page
Paging<Option> paging1 = page1.getPaging();
ResponseList<Option> page2 = facebook.fetchNext(paging1);

// Getting Previous page
Paging<Option> paging2 = page2.getPaging();
page1 = facebook.fetchPrevious(paging2);