httpcomponents 学习1--并发多线程GET
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package org.apache.http.examples.client; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.impl.conn.PoolingClientConnectionManager; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.HttpContext; import org.apache.http.util.EntityUtils; /** * An example that performs GETs from multiple threads. * */ public class ClientMultiThreadedExecution { public static void main(String[] args) throws Exception { // Create an HttpClient with the ThreadSafeClientConnManager. // This connection manager must be used if more than one thread will // be using the HttpClient. PoolingClientConnectionManager cm = new PoolingClientConnectionManager(); cm.setMaxTotal(100); HttpClient httpclient = new DefaultHttpClient(cm); try { // create an array of URIs to perform GETs on String[] urisToGet = { "http://hc.apache.org/", "http://hc.apache.org/httpcomponents-core-ga/", "http://hc.apache.org/httpcomponents-client-ga/", "http://svn.apache.org/viewvc/httpcomponents/" }; // create a thread for each URI GetThread[] threads = new GetThread[urisToGet.length]; for (int i = 0; i < threads.length; i++) { HttpGet httpget = new HttpGet(urisToGet[i]); threads[i] = new GetThread(httpclient, httpget, i + 1); } // start the threads for (int j = 0; j < threads.length; j++) { threads[j].start(); } // join the threads for (int j = 0; j < threads.length; j++) { threads[j].join(); } } finally { // When HttpClient instance is no longer needed, // shut down the connection manager to ensure // immediate deallocation of all system resources httpclient.getConnectionManager().shutdown(); } } /** * A thread that performs a GET. */ static class GetThread extends Thread { private final HttpClient httpClient; private final HttpContext context; private final HttpGet httpget; private final int id; public GetThread(HttpClient httpClient, HttpGet httpget, int id) { this.httpClient = httpClient; this.context = new BasicHttpContext(); this.httpget = httpget; this.id = id; } /** * Executes the GetMethod and prints some status information. */ @Override public void run() { System.out.println(id + " - about to get something from " + httpget.getURI()); try { // execute the method HttpResponse response = httpClient.execute(httpget, context); System.out.println(id + " - get executed"); // get the response body as an array of bytes HttpEntity entity = response.getEntity(); if (entity != null) { byte[] bytes = EntityUtils.toByteArray(entity); System.out.println(id + " - " + bytes.length + " bytes read"); } } catch (Exception e) { httpget.abort(); System.out.println(id + " - error: " + e); } } } }