Java tutorial
/**************************************************************** * Licensed to the AOS Community (AOS) under one or more * * contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The AOS licenses this file * * to you under the Apache License, Version 2.0 (the * * "License"); you may not use this file except in compliance * * with the License. You may obtain a copy of the License at * * * * http://www.apache.org/licenses/LICENSE-2.0 * * * * Unless required by applicable law or agreed to in writing, * * software distributed under the License is distributed on an * * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * * KIND, either express or implied. See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/ /* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package io.aos.protocol.http.httpcommon; import java.io.IOException; import java.util.concurrent.Future; import org.apache.http.ConnectionReuseStrategy; import org.apache.http.HttpClientConnection; import org.apache.http.HttpException; import org.apache.http.HttpHost; import org.apache.http.HttpRequestInterceptor; import org.apache.http.HttpResponse; import org.apache.http.HttpVersion; import org.apache.http.impl.DefaultConnectionReuseStrategy; import org.apache.http.impl.pool.BasicConnFactory; import org.apache.http.impl.pool.BasicConnPool; import org.apache.http.impl.pool.BasicPoolEntry; import org.apache.http.message.BasicHttpRequest; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.params.SyncBasicHttpParams; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.ExecutionContext; import org.apache.http.protocol.HttpContext; import org.apache.http.protocol.HttpProcessor; import org.apache.http.protocol.HttpRequestExecutor; import org.apache.http.protocol.ImmutableHttpProcessor; import org.apache.http.protocol.RequestConnControl; import org.apache.http.protocol.RequestContent; import org.apache.http.protocol.RequestExpectContinue; import org.apache.http.protocol.RequestTargetHost; import org.apache.http.protocol.RequestUserAgent; import org.apache.http.util.EntityUtils; /** * Elemental example for executing multiple GET requests from different threads using a connection * pool. * <p> * Please note the purpose of this application is demonstrate the usage of HttpCore APIs. * It is NOT intended to demonstrate the most efficient way of building an HTTP client. */ public class ElementalPoolingHttpGet { public static void main(String... args) throws Exception { final HttpParams params = new SyncBasicHttpParams(); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, "UTF-8"); HttpProtocolParams.setUserAgent(params, "Test/1.1"); HttpProtocolParams.setUseExpectContinue(params, true); final HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpRequestInterceptor[] { // Required protocol interceptors new RequestContent(), new RequestTargetHost(), // Recommended protocol interceptors new RequestConnControl(), new RequestUserAgent(), new RequestExpectContinue() }); final HttpRequestExecutor httpexecutor = new HttpRequestExecutor(); final BasicConnPool pool = new BasicConnPool(new BasicConnFactory(params)); pool.setDefaultMaxPerRoute(2); pool.setMaxTotal(2); HttpHost[] targets = { new HttpHost("www.google.com", 80), new HttpHost("www.yahoo.com", 80), new HttpHost("www.apache.com", 80) }; class WorkerThread extends Thread { private final HttpHost target; WorkerThread(final HttpHost target) { super(); this.target = target; } @Override public void run() { try { Future<BasicPoolEntry> future = pool.lease(this.target, null); boolean reusable = false; BasicPoolEntry entry = future.get(); try { HttpClientConnection conn = entry.getConnection(); HttpContext context = new BasicHttpContext(null); context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn); context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, this.target); BasicHttpRequest request = new BasicHttpRequest("GET", "/"); System.out.println(">> Request URI: " + request.getRequestLine().getUri()); request.setParams(params); httpexecutor.preProcess(request, httpproc, context); HttpResponse response = httpexecutor.execute(request, conn, context); response.setParams(params); httpexecutor.postProcess(response, httpproc, context); System.out.println("<< Response: " + response.getStatusLine()); System.out.println(EntityUtils.toString(response.getEntity())); ConnectionReuseStrategy connStrategy = new DefaultConnectionReuseStrategy(); reusable = connStrategy.keepAlive(response, context); } catch (IOException ex) { throw ex; } catch (HttpException ex) { throw ex; } finally { if (reusable) { System.out.println("Connection kept alive..."); } pool.release(entry, reusable); } } catch (Exception ex) { System.out.println("Request to " + this.target + " failed: " + ex.getMessage()); } } } ; WorkerThread[] workers = new WorkerThread[targets.length]; for (int i = 0; i < workers.length; i++) { workers[i] = new WorkerThread(targets[i]); } for (int i = 0; i < workers.length; i++) { workers[i].start(); } for (int i = 0; i < workers.length; i++) { workers[i].join(); } } }