http的异步请求

需要用到的包（包版本应该可能不同）：

httpcore-4.1.4.jar

httpsayncclient-4.0-alpha3.jar

httpcore-nio-4.2-alpha3.jar

/**
 * 异步http请求
 * @author Old Zhang
 *
 */
public class AsyncClientHttpExchange {
    public static void main(String[] args) throws Exception {
        sendUrl();
    }
        public static void sendUrl() throws Exception {
            String str="hello,world";
            String url="https://www.baidu.com"+"?str:"+str;
            //String response = getHttpResponse(url);
             CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault();
                httpclient.start();

                final CountDownLatch latch = new CountDownLatch(1);
                final HttpGet request = new HttpGet("https://www.baidu.com");

                System.out.println(" caller thread id is : " + Thread.currentThread().getId());

                httpclient.execute(request, new FutureCallback<HttpResponse>() {

                    public void completed(final HttpResponse response) {
                        latch.countDown();
                        System.out.println(" callback thread id is : " + Thread.currentThread().getId());
                        System.out.println(request.getRequestLine() + "->" + response.getStatusLine());
                        try {
                            String content = EntityUtils.toString(response.getEntity(), "UTF-8");
                            System.out.println(" response content is : " + content);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    public void failed(final Exception ex) {
                        latch.countDown();
                        System.out.println(request.getRequestLine() + "->" + ex);
                        System.out.println(" callback thread id is : " + Thread.currentThread().getId());
                    }

                    public void cancelled() {
                        latch.countDown();
                        System.out.println(request.getRequestLine() + " cancelled");
                        System.out.println(" callback thread id is : " + Thread.currentThread().getId());
                    }

                });
                try {
                    latch.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }

                try {
                    httpclient.close();
                } catch (IOException ignore) {

                }
            }
}