wAsync: A WebSockets/HTTP Client Library for Asynchronous Communication

wAsync is a Java based library allowing asynchronous communication with any WebServer supporting the WebSocket or Http Protocol. wAsync can be used with Node.js, Android, Atmosphere or any WebSocket Framework. To get started, read this super simple Tutorial or read the FAQ

You can browse the javadoc or browse our samples.

You can download the jar or use Maven

          <dependency>
              <groupId>org.atmosphere</groupId>
              <artifactId>wasync</artifactId>
              <version>1.4.0</version>
          </dependency>

As simple as

        Client client = ClientFactory.getDefault().newClient();

        RequestBuilder request = client.newRequestBuilder()
                .method(Request.METHOD.GET)
                .uri("http://async-io.org")
                .encoder(new Encoder<String, Reader>() {        // Stream the request body
                    @Override
                    public Reader encode(String s) {
                        return new StringReader(s);
                    }
                })
                .decoder(new Decoder<String, Reader>() {
                    @Override
                    public Reader decode(Event type, String s) {
                        return new StringReader(s);
                    }
                })
                .transport(Request.TRANSPORT.WEBSOCKET)                        // Try WebSocket
                .transport(Request.TRANSPORT.LONG_POLLING);                    // Fallback to Long-Polling

        Socket socket = client.create();
        socket.on(new Function<Reader>() {
            @Override
            public void on(Reader r) {
                // Read the response
            }
        }).on(new Function<IOException>() {

            @Override
            public void on(Throwable t) {
                // Some IOException occurred
            }

        }).open(request.build())
            .fire("echo")
            .fire("bong");

Life cycle of the underlying Socket can easily be implemented as well

           Socket socket = client.create();
           socket.on(Event.CLOSE.name(), new Function<String>() {
               @Override
               public void on(String t) {
               }
           }).on(Event.REOPENED.name(), new Function<String>() {
               @Override
               public void on(String t) {
               }
           }).on(new Function<IOException>() {
               @Override
               public void on(IOException ioe) {
                   ioe.printStackTrace();
               }
           }).on(Event.OPEN.name(), new Function<String>() {
               @Override
               public void on(String t) {
               }
           }).open(request.build());

You can also use the specialized clients. For example, to transparently enable Atmosphere's Protocol

       AtmosphereClient client = ClientFactory.getDefault().newClient(AtmosphereClient.class);

       RequestBuilder request = client.newRequestBuilder()
    		   .method(Request.METHOD.GET)
    		   .uri(targetUrl + "/suspend")
               .trackMessageLength(true)
    		   .transport(Request.TRANSPORT.LONG_POLLING);

or if you want to serialize the fire() method call so events are asynchronously sent in the order the fire method is called

        SerializedClient client = ClientFactory.getDefault().newClient(SerializedClient.class);

        SerializedOptionsBuilder b = client.newOptionsBuilder();
        b.serializedFireStage(new DefaultSerializedFireStage());

        RequestBuilder request = client.newRequestBuilder()
                .method(Request.METHOD.GET)
                .uri(targetUrl + "/suspend")
                .transport(Request.TRANSPORT.WEBSOCKET);

        Socket socket = client.create(b.build());

By default, the FunctionResolver will associate the Decoder's type will be used to invoke the appropriate Function, if defined. For example,

   Decoder<String, POJO> d = new Decoder<String, POJO>() {
             @Override
             public POJO decode(Event type, String s) {
                 if (type.equals(Event.MESSAGE)) {
                    return new POJO(s);
                 } else {
                    return s;
                 }
             }
         }

will be associated to

   Function<String> f = new Function<POJO>() {
             @Override
             public void on(POJO t) {

             }
        }

You can also implement your own FunctionResolver to associate the Function with Decoder

         Socket socket = client.create();
         socket.on("myEvent", new Function<Reader>() { ...}

where myEvent could be read from the response's body.

Want to write an Android Client? See

Build Status