Java tutorial
/* * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/tsccm/RefQueueWorker.java $ * $Revision: 673450 $ * $Date: 2008-07-02 10:35:05 -0700 (Wed, 02 Jul 2008) $ * * ==================================================================== * * 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.impl.conn.tsccm; import java.lang.ref.Reference; import java.lang.ref.ReferenceQueue; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A worker thread for processing queued references. * {@link Reference Reference}s can be * {@link ReferenceQueue queued} * automatically by the garbage collector. * If that feature is used, a daemon thread should be executing * this worker. It will pick up the queued references and pass them * on to a handler for appropriate processing. * * @deprecated Please use {@link java.net.URL#openConnection} instead. * Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a> * for further details. */ @Deprecated public class RefQueueWorker implements Runnable { private final Log log = LogFactory.getLog(getClass()); /** The reference queue to monitor. */ protected final ReferenceQueue<?> refQueue; /** The handler for the references found. */ protected final RefQueueHandler refHandler; /** * The thread executing this handler. * This attribute is also used as a shutdown indicator. */ protected volatile Thread workerThread; /** * Instantiates a new worker to listen for lost connections. * * @param queue the queue on which to wait for references * @param handler the handler to pass the references to */ public RefQueueWorker(ReferenceQueue<?> queue, RefQueueHandler handler) { if (queue == null) { throw new IllegalArgumentException("Queue must not be null."); } if (handler == null) { throw new IllegalArgumentException("Handler must not be null."); } refQueue = queue; refHandler = handler; } /** * The main loop of this worker. * If initialization succeeds, this method will only return * after {@link #shutdown shutdown()}. Only one thread can * execute the main loop at any time. */ public void run() { if (this.workerThread == null) { this.workerThread = Thread.currentThread(); } while (this.workerThread == Thread.currentThread()) { try { // remove the next reference and process it Reference<?> ref = refQueue.remove(); refHandler.handleReference(ref); } catch (InterruptedException e) { //@@@ is logging really necessary? this here is the //@@@ only reason for having a log in this class if (log.isDebugEnabled()) { log.debug(this.toString() + " interrupted", e); } } } } /** * Shuts down this worker. * It can be re-started afterwards by another call to {@link #run run()}. */ public void shutdown() { Thread wt = this.workerThread; if (wt != null) { this.workerThread = null; // indicate shutdown wt.interrupt(); } } /** * Obtains a description of this worker. * * @return a descriptive string for this worker */ @Override public String toString() { return "RefQueueWorker::" + this.workerThread; } } // class RefQueueWorker