Java example source code file (ClientEvictExpiredConnections.java)

This example source code file (ClientEvictExpiredConnections.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java tags/keywords

basichttpparams, clientconnectionmanager, clientevictexpiredconnections, defaulthttpclient, httpclient, httpentity, httpget, httpresponse, idleconnectionevictor, interruptedexception, override, schemeregistry, string, threading, threads, threadsafeclientconnmanager

The ClientEvictExpiredConnections.java example source code

/*
 * ====================================================================
 *
 *  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 java.util.concurrent.TimeUnit;

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.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;

/**
 * Example demonstrating how to evict expired and idle connections
 * from the connection pool.
 */
public class ClientEvictExpiredConnections {

    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));
        
        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/"
        };
        
        IdleConnectionEvictor connEvictor = new IdleConnectionEvictor(cm);
        connEvictor.start();
        
        for (int i = 0; i < urisToGet.length; i++) {
            String requestURI = urisToGet[i];
            HttpGet req = new HttpGet(requestURI);

            System.out.println("executing request " + requestURI);

            HttpResponse rsp = httpclient.execute(req);
            HttpEntity entity = rsp.getEntity();

            System.out.println("----------------------------------------");
            System.out.println(rsp.getStatusLine());
            if (entity != null) {
                System.out.println("Response content length: " + entity.getContentLength());
            }
            System.out.println("----------------------------------------");

            if (entity != null) {
                entity.consumeContent();
            }
        }
        
        // Sleep 10 sec and let the connection evictor do its job
        Thread.sleep(20000);
        
        // Shut down the evictor thread
        connEvictor.shutdown();
        connEvictor.join();

        // When HttpClient instance is no longer needed, 
        // shut down the connection manager to ensure
        // immediate deallocation of all system resources
        httpclient.getConnectionManager().shutdown();        
    }
    
    public static class IdleConnectionEvictor extends Thread {
        
        private final ClientConnectionManager connMgr;
        
        private volatile boolean shutdown;
        
        public IdleConnectionEvictor(ClientConnectionManager connMgr) {
            super();
            this.connMgr = connMgr;
        }

        @Override
        public void run() {
            try {
                while (!shutdown) {
                    synchronized (this) {
                        wait(5000);
                        // Close expired connections
                        connMgr.closeExpiredConnections();
                        // Optionally, close connections
                        // that have been idle longer than 5 sec
                        connMgr.closeIdleConnections(5, TimeUnit.SECONDS);
                    }
                }
            } catch (InterruptedException ex) {
                // terminate
            }
        }
        
        public void shutdown() {
            shutdown = true;
            synchronized (this) {
                notifyAll();
            }
        }
        
    }
    
}