AndroidAsync

AndroidAsync is a low level network protocol library. If you are looking for an easy to use, higher level, Android aware, http request library, check out Ion (it is built on top of AndroidAsync). The typical Android app developer would probably be more interested in Ion.

But if you're looking for a raw Socket, HTTP client/server, WebSocket, and Socket.IO library for Android, AndroidAsync is it.

Features

• Based on NIO. One thread, driven by callbacks. Highly efficient.
• All operations return a Future that can be cancelled
• Socket client + socket server
• HTTP client + server
• WebSocket client + server
• Socket.IO client

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

// 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);
    }
});