httpclient4 ThreadSafeClientConnManager 多线程程执行HTTP请求的例子

package cn.lake.util;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpVersion;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.params.ConnManagerParams;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.util.EntityUtils;

/**
 * An example that performs GETs from multiple threads.
 * 
 * @author Michael Becke
 */
public class ClientMultiThreadedExecution {

	public static void main(String[] args) throws Exception {
		// Create and initialize HTTP parameters
		HttpParams params = new BasicHttpParams();
		ConnManagerParams.setMaxTotalConnections(params, 100);
		HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);

		// Create and initialize scheme registry 
		SchemeRegistry schemeRegistry = new SchemeRegistry();
		schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
		schemeRegistry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));

		// Create an HttpClient with the ThreadSafeClientConnManager.
		// This connection manager must be used if more than one thread will
		// be using the HttpClient.
		ClientConnectionManager cm = new ThreadSafeClientConnManager(params, schemeRegistry);
		HttpClient httpClient = new DefaultHttpClient(cm, params);

		// create an array of URIs to perform GETs on
		String[] urisToGet = { "http://jakarta.apache.org/", "http://jakarta.apache.org/commons/",
				"http://jakarta.apache.org/commons/httpclient/", "http://svn.apache.org/viewvc/jakarta/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();
		}

	}

	/**
	 * 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);
			}
		}

	}

}