Download

Newest Version of the library is available via RestFB's home on Github.
View the changelog, or download it here.

The project zip contains sample code in the source/example directory which can help you get up and running quickly.

RestFB is a single JAR - just drop it into your app and you're ready to go. Download it from Maven Central:

maven central restfb version

Motivations

Design goals:

  • Minimal public API
  • Maximal extensibility
  • Robustness in the face of frequent Facebook API changes
  • Simple metadata-driven configuration
  • Zero dependencies

Non-goals:

  • Support for non-Graph/non-REST API parts of the Facebook Platform
  • Providing a mechanism for obtaining session keys or OAuth access tokens
  • Using XML as a data transfer format in addition to JSON
  • Formally-typed versions of all Facebook API methods, error codes, etc.

If RestFB doesn't meet your needs, check out sister project BatchFB. It's a good lower-level client, especially if you're concerned with batching and performance.

How To Use It

You can run some sample code, jump straight to the RestFB Javadoc, or learn by example below.

If you're looking for help or additional examples, please check out the RestFB Google Group or visit the source/examples directory in the RestFB distribution.

Initialization


// DefaultFacebookClient is the FacebookClient implementation
// that ships with RestFB. You can customize it by passing in
// custom JsonMapper and WebRequestor implementations, or simply
// write your own FacebookClient instead for maximum control.

FacebookClient facebookClient = new DefaultFacebookClient(MY_ACCESS_TOKEN);

// It's also possible to create a client that can only access
// publicly-visible data - no access token required. 
// Note that many of the examples below will not work unless you supply an access token! 

FacebookClient publicOnlyFacebookClient = new DefaultFacebookClient();

// Get added security by using your app secret:

FacebookClient facebookClient = new DefaultFacebookClient(MY_ACCESS_TOKEN, MY_APP_SECRET);

Fetching

Fetching Single Objects


// For all API calls, you need to tell RestFB how to turn the JSON
// returned by Facebook into Java objects.  In this case, the data
// we get back should be mapped to the User and Page types, respectively.
// You can write your own types too!

User user = facebookClient.fetchObject("me", User.class);
Page page = facebookClient.fetchObject("cocacola", Page.class);

out.println("User name: " + user.getName());
out.println("Page likes: " + page.getLikes());

Fetching Multiple Objects

see Graph API documentation

FetchObjectsResults fetchObjectsResults =
  facebookClient.fetchObjects(Arrays.asList("me", "cocacola"), FetchObjectsResults.class);

out.println("User name: " + fetchObjectsResults.me.getName());
out.println("Page likes: " + fetchObjectsResults.page.getLikes());

...

// Holds results from a "fetchObjects" call.
// You need to write this class yourself!

public class FetchObjectsResults {
  @Facebook
  User me;

  // If the Facebook property name doesn't match
  // the Java field name, specify the Facebook field name in the annotation.

  @Facebook("cocacola")
  Page page;
}

Fetching Objects


Connection<User> myFriends = facebookClient.fetchConnection("me/friends", User.class);
Connection<Post> myFeed = facebookClient.fetchConnection("me/feed", Post.class);

out.println("Count of my friends: " + myFriends.getData().size());
out.println("First item in my feed: " + myFeed.getData().get(0));

// Connections support paging and are iterable

for (List<Post> myFeedConnectionPage : myFeed)
  for (Post post : myFeedConnectionPage)
    out.println("Post: " + post);

Fetching Insights


// Fetching Insights data is as simple as fetching a Connection

Connection<Insight> insights = facebookClient.fetchConnection("PAGE_ID/insights", Insight.class);

for (Insight insight : insights.getData())
  out.println(insight.getName());

Logging

A few words...

Logging Example


// You'll want to initialize the bridge just once at app startup.
// In a webapp, a good place to do this is ContextLoaderListener#contextInitialized()
SLF4JBridgeHandler.install();

try {
  FacebookClient facebookClient = new DefaultFacebookClient();

  // You'll notice that logging statements from this call are bridged from java.util.logging to Log4j
  User user = facebookClient.fetchObject("btaylor", User.class);

  // ...and of course this goes straight to Log4j
  logger.debug(user);
} finally {
  // Make sure to tear down when you're done using the bridge
  SLF4JBridgeHandler.uninstall();
}

Configuration


# Example logging.properties entries
# ==================================

# to log the call to facebook including their responses
# you can change the com.restfb.HTTP log level accordingly during development time
com.restfb.HTTP.level=ALL 

# the complete restfb package logging can be configured like this
com.restfb.level=WARNING

Searching

see Graph API documentation

// Searching is just a special case of fetching Connections -
// all you have to do is pass along a few extra parameters.

Connection<Post> publicSearch =
  facebookClient.fetchConnection("search", Post.class,
    Parameter.with("q", "watermelon"), Parameter.with("type", "post"));

Connection<User> targetedSearch =
  facebookClient.fetchConnection("me/home", User.class,
    Parameter.with("q", "Mark"), Parameter.with("type", "user"));

out.println("Public search: " + publicSearch.getData().get(0).getMessage());
out.println("Posts on my wall by friends named Mark: " + targetedSearch.getData().size());

Using FQL

Executing FQL Queries

see FQL documentation

String query = "SELECT uid, name FROM user WHERE uid=220439 or uid=7901103";
List<FqlUser> users = facebookClient.executeFqlQuery(query, FqlUser.class);

out.println("Users: " + users);

...

// Holds results from an "executeFqlQuery" call.
// You need to write this class yourself!
// Be aware that FQL fields don't always map to Graph API Object fields.

public class FqlUser {
  @Facebook
  String uid;
  
  @Facebook
  String name;

  @Override
  public String toString() {
    return String.format("%s (%s)", name, uid);
  }
}

Executing Multiple FQL Queries in One Call

see FQL documentation

Map<String, String> queries = new HashMap<String, String>() {
  {
    put("users", "SELECT uid, name FROM user WHERE uid=220439 OR uid=7901103");
    put("likers", "SELECT user_id FROM like WHERE object_id=122788341354")
  }
};

MultiqueryResults multiqueryResults =
  facebookClient.executeFqlMultiquery(queries, MultiqueryResults.class);

out.println("Users: " + multiqueryResults.users);
out.println("People who liked: " + multiqueryResults.likers);

...

// Holds results from an "executeFqlMultiquery" call.
// You need to write these classes yourself (along with the FqlUser class above)!

public class FqlLiker {
  @Facebook("user_id")
  String userId;
  
  @Override
  public String toString() {
    return userId;
  }  
}

public class MultiqueryResults {
  @Facebook
  List<FqlUser> users;

  @Facebook
  List<FqlLiker> likers;
}

Advanced usage

Metadata & Introspection

see Graph API documentation
// You can specify metadata=1 for many calls, not just this one.
// See the Facebook Graph API documentation for more details. 

User userWithMetadata =
  facebookClient.fetchObject("me", User.class, Parameter.with("metadata", 1));

out.println("User metadata: has albums? "
  + userWithMetadata.getMetadata().getConnections().hasAlbums());

Passing Parameters

see Graph API documentation
// You can pass along any parameters you'd like to the Facebook endpoint.

Date oneWeekAgo = new Date(currentTimeMillis() - 1000L * 60L * 60L * 24L * 7L);

Connection<Post> filteredFeed = facebookClient.fetchConnection("me/feed", Post.class,
  Parameter.with("limit", 3), Parameter.with("until", "yesterday"),
    Parameter.with("since", oneWeekAgo));

out.println("Filtered feed count: " + filteredFeed.getData().size());

Selecting Specific Fields

see Graph API documentation

User user = facebookClient.fetchObject("me", User.class,
  Parameter.with("fields", "id, name"));

out.println("User name: " + user.getName());

Fetch Post with comments/likes total count

see July 2013 Breaking Changes

// Some Post from the GoT Fanpage with likes and comments total count
Post post = client.fetchObject("74133697733_10152424266332734", 
  Post.class, 
  Parameter.with("fields", "from,to,likes.summary(true),comments.summary(true)"));

out.println("Likes count: " + post.getLikesCount());
out.println("Likes count (from Likes): " + post.getLikes().getCount());
out.println("Comments count: " + post.getComments().getTotalCount());

Creating JSON Objects

Getting Any Kind of Data as a JSON Object


// Sometimes you can't know field names at compile time
// so the @Facebook annotation can't be used.
// Or maybe you'd like full control over the data that gets returned.
// Either way, RestFB has you covered.  Just map any API call to JsonObject.

// Here's how to fetch a single object

JsonObject btaylor = facebookClient.fetchObject("btaylor", JsonObject.class);
out.println(btaylor.getString("name"));

// Here's how to fetch a connection

JsonObject photosConnection = facebookClient.fetchObject("me/photos", JsonObject.class);
String firstPhotoUrl = photosConnection.getJsonArray("data").getJsonObject(0).getString("source");
out.println(firstPhotoUrl);

// Here's how to handle an FQL query

String query = "SELECT uid, name FROM user WHERE uid=220439 or uid=7901103";
List<JsonObject> queryResults = facebookClient.executeFqlQuery(query, JsonObject.class);
out.println(queryResults.get(0).getString("name"));

// Sometimes it's helpful to use JsonMapper directly if you're working with JsonObjects.

List<String> ids = new ArrayList<String>();
ids.add("btaylor");
ids.add("http://www.imdb.com/title/tt0117500/");

// First, make the API call...

JsonObject results = facebookClient.fetchObjects(ids, JsonObject.class);

// ...then pull out raw JSON data and map each type "by hand".
// Normally your FacebookClient uses a JsonMapper internally, but
// there's nothing stopping you from using it too!

JsonMapper jsonMapper = new DefaultJsonMapper();
User user = jsonMapper.toJavaObject(results.getString("btaylor"), User.class);
Url url = jsonMapper.toJavaObject(results.getString("http://restfb.com"), Url.class);

out.println("User is " + user);
out.println("URL is " + url);

Publishing

Publishing a Message and Event

see Graph API documentation
// Publishing a simple message.
// FacebookType represents any Facebook Graph Object that has an ID property.

FacebookType publishMessageResponse =
  facebookClient.publish("me/feed", FacebookType.class,
    Parameter.with("message", "RestFB test"));

out.println("Published message ID: " + publishMessageResponse.getId());

// Publishing an event

Date tomorrow = new Date(currentTimeMillis() + 1000L * 60L * 60L * 24L);
Date twoDaysFromNow = new Date(currentTimeMillis() + 1000L * 60L * 60L * 48L);

FacebookType publishEventResponse = facebookClient.publish("me/events", FacebookType.class,
  Parameter.with("name", "Party"), Parameter.with("start_time", tomorrow),
    Parameter.with("end_time", twoDaysFromNow));

out.println("Published event ID: " + publishEventResponse.getId());

Publishing a Photo

see Graph API documentation
// Publishing an image to a photo album is easy!
// Just specify the image you'd like to upload and RestFB will handle it from there.

FacebookType publishPhotoResponse = facebookClient.publish("me/photos", FacebookType.class,
  BinaryAttachment.with("cat.png", getClass().getResourceAsStream("/cat.png")),
  Parameter.with("message", "Test cat"));

out.println("Published photo ID: " + publishPhotoResponse.getId());

// Publishing a video works the same way.

facebookClient.publish("me/videos", FacebookType.class,
  BinaryAttachment.with("cat.mov", getClass().getResourceAsStream("/cat.mov")),
  Parameter.with("message", "Test cat"));

Publishing a Checkin

see Graph API documentation
Map<String, String> coordinates = new HashMap<String, String>();
coordinates.put("latitude", "37.06");
coordinates.put("longitude", "-95.67");
			
FacebookType publishCheckinResponse = facebookClient.publish("me/checkins",
  FacebookType.class, Parameter.with("message", "I'm here!"),
    Parameter.with("coordinates", coordinates), Parameter.with("place", 1234)));

out.println("Published checkin ID: " + publishCheckinResponse.getId());

Deleting

see Graph API documentation
Boolean deleted = facebookClient.deleteObject("some object ID");
out.println("Deleted object? " + deleted);

Batch API

Using Batch Request API

see Graph API documentation
// The Batch API is great if you have multiple operations you'd like to
// perform in one server trip. Let's build a batch with three GET requests and
// one POST request here:

BatchRequest meRequest = new BatchRequestBuilder("me").build();
BatchRequest badRequest = new BatchRequestBuilder("this-is-a-bad-request/xxx").build();
BatchRequest m83musicRequest = new BatchRequestBuilder("m83music/feed")
  .parameters(Parameter.with("limit", 5)).build();
BatchRequest postRequest = new BatchRequestBuilder("me/feed")
  .method("POST")
  .body(Parameter.with("message", "Testing!")).build();

// ...and execute the batch.

List<BatchResponse> batchResponses =
  facebookClient.executeBatch(meRequest, badRequest, m83musicRequest, postRequest);

// Responses are ordered to match up with their corresponding requests.

BatchResponse meResponse = batchResponses.get(0);
BatchResponse badResponse = batchResponses.get(1);
BatchResponse m83musicResponse = batchResponses.get(2);
BatchResponse postResponse = batchResponses.get(3);

// Since batches can have heterogenous response types, it's up to you
// to parse the JSON into Java objects yourself. Luckily RestFB has some built-in
// support to help you with this.

JsonMapper jsonMapper = new DefaultJsonMapper();

// Here we marshal to the built-in User type.

User me = jsonMapper.toJavaObject(meResponse.getBody(), User.class);
out.println(me);

// To detect errors, check the HTTP response code.

if(badResponse.getCode() != 200)
  out.println("Batch request failed: " + badResponse);

// You can pull out connection data...

out.println("M83's feed follows");

Connection<Post> m83musicPosts =
  new Connection<Post>(facebookClient, m83musicResponse.getBody(), Post.class);

for (List<Post> m83musicPostsConnectionPage : m83musicPosts)
  for (Post post : m83musicPostsConnectionPage)
    out.println(post);

// ...or do whatever you'd like with the raw JSON.

out.println(postResponse.getBody());

Including Binary Attachments Using the Batch Request API

see Graph API documentation
// Per the FB Batch API documentation, attached_files is a comma-separated list
// of attachment names to include in the API call.
// RestFB will use the filename provided to your BinaryAttachment minus the file
// extension as the name of the attachment.
// For example, "cat-pic.png" must be referenced here as "cat-pic". 

List<BatchRequest> batchRequests = Arrays.asList(
  new BatchRequestBuilder("me/photos").attachedFiles("cat-pic").build(),
  new BatchRequestBuilder("me/videos")
    .attachedFiles("cat-vid, cat-vid-2")
    .body(Parameter.with("message", "This cat is hilarious"))
    .build());

// Define the list of attachments to include in the batch.

List<BinaryAttachment> binaryAttachments = Arrays.asList(
  BinaryAttachment.with("cat-pic.png", getClass().getResourceAsStream("/cat-pic.png")),
  BinaryAttachment.with("cat-vid.mov", getClass().getResourceAsStream("/cat-vid.mov")),
  BinaryAttachment.with("cat-vid-2.mov", getClass().getResourceAsStream("/cat-vid-2.mov")));

// Finally, execute the batch.

facebookClient.executeBatch(batchRequests, binaryAttachments);

Access Token Operations

Get Login Dialog URL

Before you can build your Facebook Login Dialog URL you need to look deeper into the the scope concept. Every Access Token is bound to a scope and a scope is a set of permissions. The developer decides which permissions are needed to get the application working correctly.

RestFB supports the developer building the scope and so you should use the ScopeBuilder. The permissions are implemented as Enums. Here's an example how to build a scope:


ScopeBuilder scopeBuilder = new ScopeBuilder();
scopeBuilder.addPermission(UserDataPermissions.USER_STATUS);
scopeBuilder.addPermission(UserDataPermissions.USER_ABOUT_ME);			
			

With the ScopeBuilder you can now easily build the login dialog url, like this:


FacebookClient client = new DefaultFacebookClient(Version.VERSION_2_2);
String loginDialogUrlString = client.getLoginDialogUrl(appId, redirectUrl, scopeBuilder);
			

Extending an Access Token

see Graph API documentation

// Tells Facebook to extend the lifetime of MY_ACCESS_TOKEN.
// Facebook may return the same token or a new one.

AccessToken accessToken =
  new DefaultFacebookClient().obtainExtendedAccessToken(MY_APP_ID,
    MY_APP_SECRET, MY_ACCESS_TOKEN);

out.println("My extended access token: " + accessToken);

Getting an Application Access Token

see Graph API documentation

// Obtains an access token which can be used to perform Graph API operations
// on behalf of an application instead of a user.

AccessToken accessToken =
  new DefaultFacebookClient().obtainAppAccessToken(MY_APP_ID, MY_APP_SECRET);

out.println("My application access token: " + accessToken);

Security Operations

Parsing Signed Requests


// Facebook can send you an encoded signed request, which is only decodable by you
// with your App Secret. Pass the signed request, your app secret, and a class that
// specifies how RestFB should map the decoded signed request JSON.

String signedRequest = "xxx";
String appSecret = "yyy";
Payload payload = facebookClient.parseSignedRequest(signedRequest,
  appSecret, Payload.class);

out.println("Signed request user_id: " + payload.userId);

// You must write your own class to hold signed request payload data
// since RestFB can't know in advance what fields FB will be sending you.
// Some are always present, like user_id, but the rest will be specific
// to your app and situation.

class Payload {
  @Facebook("user_id")
  String userId;

  @Facebook("oauth_token")
  String oauthToken;

  @Facebook
  Long expires;

  @Facebook("issued_at")
  Long issuedAt;

  Date getExpires() {
    return expires == null ? null : new Date(expires * 1000L);
  }

  Date getIssuedAt() {
    return issuedAt == null ? null : new Date(issuedAt * 1000L);
  }
  
  // Add whatever other fields you might have
}

Parsing Deauthorization Callback request


// Facebook can send you an encoded signed request, as soon as someone deletes
// your Facebook app. This only happens, if you have defined a deauthorization
// callback url in your Facebook App (Settings -> Advanced).

String signedRequest = "xxx";
String appSecret = "yyy";
DeAuth deauthObj = facebookClient.parseSignedRequest(signedRequest,
  appSecret, DeAuth.class);

out.println("This user just deleted your app: " + deauthObj.getUserId());
out.println("Deauthorization at: " + deauthObj.getIssuedAt());

Generating appsecret_proof


// If you create a DefaultFacebookClient instance with your app secret, RestFB will
// automatically include appsecret_proof with your requests,
// no work needs to be done on your end.

FacebookClient facebookClient =
  new DefaultFacebookClient(MY_ACCESS_TOKEN, MY_APP_SECRET);

// Request will include appsecret_proof

facebookClient.fetchObject("XXX", User.class);

// You may also generate the appsecret_proof value directly (not normally needed).

String proof = new DefaultFacebookClient().obtainAppSecretProof(
  MY_ACCESS_TOKEN, MY_APP_SECRET);
out.println("Here's my proof: " + proof);

Running The Examples

RestFB comes with a few example Java source files that you can run and tweak yourself. Don't forget to put your access token inside the quotes!

$ cd source/example
$ ant run-reader-examples "-Daccess_token=MY_ACCESS_TOKEN"
$ ant run-publisher-examples "-Daccess_token=MY_ACCESS_TOKEN"
$ ant run-legacy-examples "-Daccess_token=MY_ACCESS_TOKEN"

Supported Graph Object Types

RestFB can map JSON to any class that has fields annotated with the @Facebook annotation, which is discussed in more detail in the JSON Mapping Rules section.

However, for your convenience, all basic Graph API Object types have their own Java implementation in the com.restfb.types package.

You may use these builtin types if you wish, or you can subclass them to add additional fields or functionality, or just write your own if you have special requirements. The builtins come with reflective implementations of toString(), hashCode(), and equals(Object o) to make your life simpler. If you subclass any of the builtins and add additional fields with accessors, those fields will be automatically taken into account by the above 3 methods.

The builtin types are as follows:

JSON Mapping Rules

Using DefaultJsonMapper, RestFB is able to recursively map JSON fields annotated with @Facebook to the following Java types out of the box:

  • The convenience classes provided by RestFB in com.restfb.types
  • String
  • Integer
  • Boolean
  • Long
  • Double
  • Float
  • BigInteger
  • BigDecimal
  • Your own JavaBean-compliant classes
    Don't forget to provide a public default constructor!
  • Lists of any of the above types

For example:


public class MyClass {
  @Facebook
  String name;

  @Facebook
  BigDecimal value;
  
  // If a Facebook field doesn't match your field's name, specify it explicitly

  @Facebook("lots_of_numbers")
  List<Integer> lotsOfNumbers;
  
  // You can annotate methods with @JsonMappingCompleted to perform
  // post-mapping operations.
  //
  // This is useful if you want to massage the data FB returns.
  
  @JsonMappingCompleted
  void allDone(JsonMapper jsonMapper) {  	
    if(lotsOfNumbers.size() == 0)
      throw new IllegalStateException("I was expecting more numbers!");
  }
}

Java to JSON mapping is supported by default via JsonMapper.toJson(Object object). You may recursively convert primitive wrapper types as specified above, Lists, Maps with String keys, and your own Javabean types by applying the @Facebook annotation to any fields you'd like to include in the conversion.

The default behavior of DefaultJsonMapper is to throw a FacebookJsonMappingException if it cannot map JSON to Java correctly. However, given the frequency with which the Facebook API changes, you might want to guard yourself from "surprise" errors in production by exerting more fine-grained control over how the mapper handles mapping exceptions. You can do so like this:

FacebookClient facebookClient = new DefaultFacebookClient("MY_ACCESS_TOKEN",
  new DefaultWebRequestor(), new DefaultJsonMapper(new JsonMappingErrorHandler() {
    public boolean handleMappingError(String unmappableJson, Class<?> targetType, Exception e) {
      
      // Here you might log the fact that JSON mapping failed.
      
      err.println(format("Uh oh, mapping %s to %s failed...", unmappableJson, targetType));

      // Returning true tells the mapper to map this JSON as null and keep going.
      // Returning false tells the mapper to throw an exception.
      
      return true;
    }
  }));

As-is, DefaultJsonMapper should meet the needs of the vast majority of users. If it doesn't support a feature you need, you can easily subclass it or write your own implementation of JsonMapper instead.

Error Handling

All FacebookClient methods may throw FacebookException, which is an unchecked exception as of RestFB 1.6.

These are the FacebookException subclasses that you may catch:

  • FacebookJsonMappingException
    Thrown when an error occurs when attempting to map Facebook API response JSON to a Java object. It usually indicates that you've used the @Facebook annotation on a field with an unsupported type or the Facebook API JSON doesn't map correctly to the fields you've annotated (e.g. attempting to map a JSON string to a Java BigDecimal or a JSON object to a Java List).
    You generally should not explicitly catch this exception in your code, as it usually signifies programmer error in setting up @Facebook annotations. One valid use for catching this exception, however, is to detect when Facebook changes what an API call returns on their end, which would break your live code. It may be useful to catch this exception and then send a notification to you or your ops team to notify them that your application needs to be updated.
  • FacebookNetworkException
    Thrown when a failure occurs at the network level. This can happen if your machine doesn't have a network connection or the Facebook API endpoint returns an unexpected HTTP status code. If there's an HTTP status code available, it's included in the exception so you may take custom actions depending on what type of error occurred.
  • FacebookGraphException
    Thrown when the Graph API returns an error, as shown in the example JSON snippet below. Exposes the type and message so you can handle them in your code and take custom action as needed.
    {
      "error": {
        "type": "SomeBizarreTypeOfException",
        "message": "Everything went wrong."
      }
    }
    Note that FacebookGraphException is a catchall Graph API exception. For your convenience, RestFB will throw more-specific subclasses FacebookOAuthException and FacebookQueryParseException if it detects either of these Graph API error types. These are described below.
  • FacebookOAuthException
    Thrown when the Graph API returns an OAuth-related error (type OAuthException or OAuthAccessTokenException), as shown in the example JSON snippet below.
    {
      "error": {
        "type": "OAuthException",
        "message": "Invalid access token signature."
      }
    }
  • FacebookQueryParseException
    Thrown when the Graph API returns an FQL query parsing error (type QueryParseException), as shown in the example JSON snippet below.
    {
      "error": {
        "type": "QueryParseException",
        "message": "Unknown path components: /fizzle"
      }
    }
  • FacebookResponseStatusException
    This is thrown by RestFB when an FQL call fails. FacebookGraphException and its subclasses are not applicable in that case because Facebook returns this "legacy" exception instead due to FQL not yet being a full-fledged member of the Graph API. FacebookResponseStatusException will include both the error code and error message returned by the Facebook API so you may take custom actions depending on the type of error that occurred.
  • FacebookResponseContentException
    This is thrown by RestFB when Facebook responds with unexpected data. For example, when extending an access token, Facebook should return an HTTP response body of the form access_token=123&expires=456. But if Facebook does not respond as expected - perhaps they modify the response format in some future API release - FacebookResponseContentException will be thrown.
    It is unlikely that you will ever see this exception.

Here's some example code to illustrate the above. Keep in mind that your code doesn't need to handle every single exception the way we're doing here - this is just to demonstrate what's possible.


String query = "SELECT name FROM user WHERE uid=220439 or uid=7901103";

try {
  List<User> users = facebookClient.executeFqlQuery(query, User.class); 
} catch (FacebookJsonMappingException e) {
  // Looks like this API method didn't really return a list of users
} catch (FacebookNetworkException e) {
  // An error occurred at the network level
  out.println("API returned HTTP status code " + e.getHttpStatusCode());
} catch (FacebookOAuthException e) {
  // Authentication failed - bad access token?  
} catch (FacebookGraphException e) {
  // The Graph API returned a specific error
  out.println("Call failed. API says: " + e.getErrorMessage());
} catch (FacebookResponseStatusException e) {
  // Old-style Facebook error response.
  // The Graph API only throws these when FQL calls fail.
  // You'll see this exception more if you use the Old REST API
  // via LegacyFacebookClient.
  if (e.getErrorCode() == 200)
    out.println("Permission denied!");
} catch (FacebookException e) {
  // This is the catchall handler for any kind of Facebook exception
}

Here's some example code to illustrate the above. Keep in mind that your code doesn't need to handle every single exception the way we're doing here - this is just to demonstrate what's possible.

Extensibility and Unit Testing

In addition to FacebookClient, RestFB provides default implementations for WebRequestor and JsonMapper, two components that DefaultFacebookClient depends on to do its work.

These dependencies are designed to allow for straightforward subclassing (if you only want to replace a little bit of functionality) and simple custom implementations (if you require full control).

This comes in handy when unit testing - for example, you can write your own WebRequestor implementation that simulates a Facebook API endpoint response. You can drop in custom data designed to exercise your application's Facebook integration or simulate error conditions to make sure you're handling them properly.

Here's a trivial example which shows one way you might implement this:


FacebookClient facebookClient = new DefaultFacebookClient(MY_ACCESS_TOKEN,  

  // A one-off DefaultWebRequestor for testing that returns a hardcoded JSON
  // object instead of hitting the Facebook API endpoint URL

  new DefaultWebRequestor() {
    @Override
    public Response executeGet(String url) throws IOException {
      return new Response(HttpURLConnection.HTTP_OK,
        "{'id':'123456','name':'Test Person'}");
    }
  }, new DefaultJsonMapper());

// Make an API request using the mocked WebRequestor

User user = facebookClient.fetchObject("ignored", User.class); 

// Make sure we got what we were expecting

assert "123456".equals(user.getId());
assert "Test Person".equals(user.getName());

Boost Performance

Generating a SimpleDateFormat instance is incredibly expensive and you should not generate a new formatter for every date string you have to parse. Therefore RestFB provides the possibility to replace the old and slow parsing with a faster solution. But you have to take care of some cleanup because the higher speed can result in a small memory leak. Of course RestFB provides everything you need to do it right.

With version 1.7.0 you can decide which DateFormatStrategy you use. The default strategy is the SimpleDateFormatStrategy. It's almost the same behavior as in the versions before 1.7.0 and you don't need to change anything.

The faster stretegy is called CachedDateFormatStrategy. You have to set this manually in the DateUtils singleton and call the clearThreadLocal method at the end of a thread to prevent the memory leak mentioned above. You should have a look at the code example below.

Because we provide the DateFormatStrategy as an interface you can implement your own strategy.


DateUtils.setDateFormatStrategy(new CachedDateFormatStrategy());
// do your normal stuff in that thread
...
// clean the thread local cache just before you finish the thread
DateFormatStrategy strategy = DateUtils.getDateFormatStrategy();
if (strategy instanceof CachedDateFormatStrategy)
  ((CachedDateFormatStrategy)strategy).clearThreadLocal();
			

ETag support

You can improve your connection's performance by using the ETagWebRequestor. This WebRequestor is a special implementation wich adds ETag support to the restfb's requests. For further information about ETag you should have a look at the wikipedia page.


// create the special WebRequestor with ETag support
ETagWebRequestor webRequestor = new ETagWebRequestor();
FacebookClient client = new DefaultFacebookClient(accessToken, webRequestor, new DefaultJsonMapper(), Version.VERSION_2_2);
			

Links

Visit RestFB's home on Github.

Have a question not covered here? Ask in the RestFB Google Group.

Found a bug or have an enhancement request? Create a ticket in the issue tracker.

Download a read-only copy of the current source code using Git:

git clone git://github.com/restfb/restfb.git

RestFB Users

If you're a happy RestFB user and would like to add a link to your site, please send me an email.

About

RestFB was created by Mark Allen, is maintained by Norbert Bartels, and sponsored by Transmogrify, LLC.

Transmogrify is a Philadelphia-area software shop specializing in product design and web/mobile software development. Our experience runs the gamut from embedded systems to Oracle DBA work to the cutting-edge web framework and iOS/Android technologies. Give us a call at (215) 436-XMOG or send an email to product@xmog.com if you need a hand with anything software-related. We can handle every part of the software lifecycle, from initial requirements and design to ongoing maintenance and support.

Development of RestFB was aided by

Website icons provided by Mark James.

Licensing

RestFB is open source software released under the terms of the MIT License:

Copyright (c) 2010-2015 Mark Allen. 

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.