Async Http ClientCopyright 2010 Ning IncDESCRIPTION-----------Issue tracker:https://issues.sonatype.org/browse/AHCJavadoc:http://sonatype.github.com/async-http-client/apidocs/index.htmlGetting started:http://is.gd/kexrN (PDF)http://is.gd/ja6My (HTML)Async Http Client library purpose is to allow Java applications to easily execute HTTP requests and asynchronously process the HTTP responses. The Async HTTP Client library is simple to use. First, in order to add it to your Maven project, simply add this dependency:        <repository>            <id>Sonatype</id>            <name>Sonatype Release</name>            <url>http://oss.sonatype.org/content/repositories/releases </url>        </repository>and then define the dependency as:         <dependency>             <groupId>com.ning</groupId>             <artifactId>async-http-client</artifactId>             <version>1.6.2</version>         </dependency>You can also download the artifacthttp://oss.sonatype.org/content/repositories/releasesThen in your code you can simply do:    import com.ning.http.client.*;    import java.util.concurrent.Future;    AsyncHttpClient asyncHttpClient = new AsyncHttpClient();    Future<Response> f = asyncHttpClient.prepareGet("http://www.ning.com/ ").execute();    Response r = f.get();You can also accomplish asynchronous operation without using a Future if you want to receive and process the response in your handler:    import com.ning.http.client.*;    import java.util.concurrent.Future;    AsyncHttpClient asyncHttpClient = new AsyncHttpClient();    asyncHttpClient.prepareGet("http://www.ning.com/ ").execute(new AsyncCompletionHandler<Response>(){                @Override        public Response onCompleted(Response response) throws Exception{            // Do something with the Response            // ...            return response;        }                @Override        public void onThrowable(Throwable t){            // Something wrong happened.        }    });You can also mix Future with AsyncHandler to only retrieve part of the asynchronous response    import com.ning.http.client.*;    import java.util.concurrent.Future;    AsyncHttpClient asyncHttpClient = new AsyncHttpClient();    Future<Integer> f = asyncHttpClient.prepareGet("http://www.ning.com/ ").execute(new AsyncCompletionHandler<Integer>(){                @Override        public Integer onCompleted(Response response) throws Exception{            // Do something with the Response            return response.getStatusCode();        }                @Override        public void onThrowable(Throwable t){            // Something wrong happened.        }    });        int statuѕCode = f.get(); You have full control on the Response life cycle, so you can decide at any moment to stop processing what the server is sending back:      import com.ning.http.client.*;      import java.util.concurrent.Future;      AsyncHttpClient c = new AsyncHttpClient();      Future<String> f = c.prepareGet("http://www.ning.com/ ").execute(new AsyncHandler<String>() {          private StringBuilder builder = new StringBuilder();          @Override          public STATE onStatusReceived(HttpResponseStatus status) throws Exception {              int statusCode = status.getStatusCode();               // The Status have been read               // If you don't want to read the headers,body or stop processing the response               return STATE.ABORT;          }          @Override          public STATE onHeadersReceived(HttpResponseHeaders h) throws Exception {              Headers headers = h.getHeaders();               // The headers have been read               // If you don't want to read the body, or stop processing the response               return STATE.ABORT;          }          @Override          public STATE onBodyPartReceived(HttpResponseBodyPart bodyPart) throws Exception {               builder.append(new String(bodyPart.getBodyPartBytes()));               return STATE.CONTINU          }          @Override          public String onCompleted() throws Exception {               // Will be invoked once the response has been fully read or a ResponseComplete exception               // has been thrown.               return builder.toString();          }          @Override          public void onThrowable(Throwable t) {          }      });            String bodyResponse = f.get();Finally, you can also configure the AsyncHttpClient via it's AsyncHttpClientConfig object:        AsyncHttpClientConfig cf = new AsyncHttpClientConfig.Builder().setProxyServer(new ProxyServer("127.0.0.1", 38080)).build();        AsyncHttpClient c = new AsyncHttpClient(cf);The library uses Java non blocking I/O for supporting asynchronous operations. The default asynchronous provider is build on top of Netty (http://www.jboss.org/netty), the Java NIO Client Server Socket Framework from JBoss, but the library exposes a configurable provider SPI which allows to easily plug in other frameworks.Keep up to date on the library development by joining the Asynchronous HTTP Client discussion grouphttp://groups.google.com/group/asynchttpclient