Java异步执行多个HTTP请求的例子（需要apache http类库）

import java.util.concurrent.CountDownLatch;

import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;

 
public class AsyncClientHttpExchangeFutureCallback {

    public static void main(final String[] args) throws Exception {
        RequestConfig requestConfig = RequestConfig.custom()
            .setSocketTimeout(3000)
            .setConnectTimeout(3000).build();
        CloseableHttpAsyncClient httpclient = HttpAsyncClients.custom()
            .setDefaultRequestConfig(requestConfig)
            .build();
        try {
            httpclient.start();
            final HttpGet[] requests = new HttpGet[] {
                    new HttpGet("http://www.apache.org/"),
                    new HttpGet("https://www.verisign.com/"),
                    new HttpGet("http://www.googleXXXXXXXXXXXXXXXXXXXXXX.com/")
            };
            final CountDownLatch latch = new CountDownLatch(requests.length);
            for (final HttpGet request: requests) {
                httpclient.execute(request, new FutureCallback<HttpResponse>() {

                    @Override
                    public void completed(final HttpResponse response) {
                        latch.countDown();
                        System.out.println(request.getRequestLine() + "->" + response.getStatusLine());
                    }

                    @Override
                    public void failed(final Exception ex) {
                        latch.countDown();
                        System.out.println(request.getRequestLine() + "->" + ex);
                    }

                    @Override
                    public void cancelled() {
                        latch.countDown();
                        System.out.println(request.getRequestLine() + " cancelled");
                    }

                });
            }
            latch.await();
            System.out.println("Shutting down");
        } finally {
            httpclient.close();
        }
        System.out.println("Done");
    }

}

原文：http://www.cnblogs.com/starcrm/p/5216303.html