/*

 * ====================================================================

 *

 *  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 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);

            }

        }

    }

}