1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27 package org.apache.hc.client5.http.examples;
28
29 import org.apache.hc.client5.http.classic.methods.HttpGet;
30 import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
31 import org.apache.hc.client5.http.impl.classic.HttpClients;
32 import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager;
33 import org.apache.hc.core5.http.HttpEntity;
34 import org.apache.hc.core5.http.io.entity.EntityUtils;
35 import org.apache.hc.core5.http.protocol.BasicHttpContext;
36 import org.apache.hc.core5.http.protocol.HttpContext;
37
38 /**
39 * An example that performs GETs from multiple threads.
40 *
41 */
42 public class ClientMultiThreadedExecution {
43
44 public static void main(final String[] args) throws Exception {
45 // Create an HttpClient with the PoolingHttpClientConnectionManager.
46 // This connection manager must be used if more than one thread will
47 // be using the HttpClient.
48 final PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
49 cm.setMaxTotal(100);
50
51 try (final CloseableHttpClient httpclient = HttpClients.custom()
52 .setConnectionManager(cm)
53 .build()) {
54 // create an array of URIs to perform GETs on
55 final String[] urisToGet = {
56 "http://hc.apache.org/",
57 "http://hc.apache.org/httpcomponents-core-ga/",
58 "http://hc.apache.org/httpcomponents-client-ga/",
59 };
60
61 // create a thread for each URI
62 final GetThread[] threads = new GetThread[urisToGet.length];
63 for (int i = 0; i < threads.length; i++) {
64 final HttpGet httpget = new HttpGet(urisToGet[i]);
65 threads[i] = new GetThread(httpclient, httpget, i + 1);
66 }
67
68 // start the threads
69 for (final GetThread thread : threads) {
70 thread.start();
71 }
72
73 // join the threads
74 for (final GetThread thread : threads) {
75 thread.join();
76 }
77
78 }
79 }
80
81 /**
82 * A thread that performs a GET.
83 */
84 static class GetThread extends Thread {
85
86 private final CloseableHttpClient httpClient;
87 private final HttpContext context;
88 private final HttpGet httpget;
89 private final int id;
90
91 public GetThread(final CloseableHttpClient httpClient, final HttpGet httpget, final int id) {
92 this.httpClient = httpClient;
93 this.context = new BasicHttpContext();
94 this.httpget = httpget;
95 this.id = id;
96 }
97
98 /**
99 * Executes the GetMethod and prints some status information.
100 */
101 @Override
102 public void run() {
103 try {
104 System.out.println(id + " - about to get something from " + httpget.getUri());
105 this.httpClient.execute(httpget, response -> {
106 System.out.println(id + " - get executed");
107 // get the response body as an array of bytes
108 final HttpEntity entity = response.getEntity();
109 if (entity != null) {
110 final byte[] bytes = EntityUtils.toByteArray(entity);
111 System.out.println(id + " - " + bytes.length + " bytes read");
112 }
113 return null;
114 });
115 } catch (final Exception e) {
116 System.out.println(id + " - error: " + e);
117 }
118 }
119
120 }
121
122 }