AndroidAsync

Asynchronous socket, http (client+server), websocket, and socket.io library.

It uses java.nio to manage connections. All the connections are thus managed on a single thread, rather than one per thread. NIO is extremely efficient.

Download

Download the latest JAR or grab via Maven:

<dependency>
    <groupId>com.koushikdutta.async</groupId>
    <artifactId>androidasync</artifactId>
    <version>(insert latest version)</version>
</dependency>

Download a url to a String

// url is the URL to download. The callback will be invoked on the UI thread
// once the download is complete.
AsyncHttpClient.getDefaultInstance().getString(url, new AsyncHttpClient.StringCallback() {
    // Callback is invoked with any exceptions/errors, and the result, if available.
    @Override
    public void onCompleted(Exception e, AsyncHttpResponse response, String result) {
        if (e != null) {
            e.printStackTrace();
            return;
        }
        System.out.println("I got a string: " + result);
    }
});

Download JSON from a url

// url is the URL to download. The callback will be invoked on the UI thread
// once the download is complete.
AsyncHttpClient.getDefaultInstance().getJSONObject(url, new AsyncHttpClient.JSONObjectCallback() {
    // Callback is invoked with any exceptions/errors, and the result, if available.
    @Override
    public void onCompleted(Exception e, AsyncHttpResponse response, JSONObject result) {
        if (e != null) {
            e.printStackTrace();
            return;
        }
        System.out.println("I got a JSONObject: " + result);
    }
});

Download a url to a file

AsyncHttpClient.getDefaultInstance().getFile(url, filename, new AsyncHttpClient.FileCallback() {
    @Override
    public void onCompleted(Exception e, AsyncHttpResponse response, File result) {
        if (e != null) {
            e.printStackTrace();
            return;
        }
        System.out.println("my file is available at: " + result.getAbsolutePath());
    }
});

Caching is supported too (experimental)

// arguments are the http client, the directory to store cache files, and the size of the cache in bytes
ResponseCacheMiddleware.addCache(AsyncHttpClient.getDefaultInstance(),
                                  getFileStreamPath("asynccache"),
                                  1024 * 1024 * 10);

Can also create web sockets:

AsyncHttpClient.getDefaultInstance().websocket(get, "my-protocol", new WebSocketConnectCallback() {
    @Override
    public void onCompleted(Exception ex, WebSocket webSocket) {
        if (ex != null) {
            ex.printStackTrace();
            return;
        }
        webSocket.send("a string");
        webSocket.send(new byte[10]);
        webSocket.setStringCallback(new StringCallback() {
            public void onStringAvailable(String s) {
                System.out.println("I got a string: " + s);
            }
        });
        webSocket.setDataCallback(new DataCallback() {
            public void onDataAvailable(ByteBufferList byteBufferList) {
                System.out.println("I got some bytes!");
                // note that this data has been read
                byteBufferList.clear();
            }
        });
    }
});

AndroidAsync also supports socket.io

SocketIOClient.connect(AsyncHttpClient.getDefaultInstance(), "http://192.168.1.2:3000", new SocketIOConnectCallback() {
    @Override
    public void onConnectCompleted(Exception ex, SocketIOClient client) {
        if (ex != null) {
            ex.printStackTrace();
            return;
        }
        client.setStringCallback(new StringCallback() {
            @Override
            public void onString(String string) {
                System.out.println(string);
            }
        });
        client.setEventCallback(new EventCallback() {
            @Override
            public void onEvent(String event, JSONArray arguments) {
                System.out.println("event: " + event + " args: " + arguments.toString());
            }
        });
        client.setJSONCallback(new JSONCallback() {
            @Override
            public void onJSON(JSONObject json) {
                System.out.println("json: " + json.toString());
            }
        });
    }
});

Need to do multipart/form-data uploads? That works too.

AsyncHttpPost post = new AsyncHttpPost("http://myservercom/postform.html");
MultipartFormDataBody body = new MultipartFormDataBody();
body.addFilePart("my-file", new File("/path/to/file.txt");
body.addStringPart("foo", "bar");
post.setBody(body);
AsyncHttpClient.getDefaultInstance().execute(post, new StringCallback() {
    @Override
    public void onCompleted(Exception e, AsyncHttpResponse source, String result) {
        if (e != null) {
            ex.printStackTrace();
            return;
        }
        System.out.println("Server says: " + result);
    }
});

AndroidAsync also let's you create simple HTTP servers (and websocket servers):

AsyncHttpServer server = new AsyncHttpServer();
server.get("/", new HttpServerRequestCallback() {
    @Override
    public void onRequest(AsyncHttpServerRequest request, AsyncHttpServerResponse response) {
        response.send("Hello!!!");
    }
});
// listen on port 5000
server.listen(5000);
// browsing http://localhost:5000 will return Hello!!!

Futures

All the API calls return Futures.

Future<String> string = client.getString("http://foo.com/hello.txt");
// this will block, and may also throw if there was an error!
String value = string.get();

Futures can also have callbacks...

Future<String> string = client.getString("http://foo.com/hello.txt");
string.setCallback(new FutureCallback<String>() {
    @Override
    public void onCompleted(Exception e, String result) {
        System.out.println(result);
    }
});

For brevity...

client.getString("http://foo.com/hello.txt")
.setCallback(new FutureCallback<String>() {
    @Override
    public void onCompleted(Exception e, String result) {
        System.out.println(result);
    }
});