package com.heaton.bot;/** * This is a very simple object that * allows the spider to determine when * it is done. This object implements * a simple lock that the spider class * can wait on to determine completion. * Done is defined as the spider having * no more work to complete. * * Copyright 2001-2003 by Jeff Heaton (http://www.jeffheaton.com) * * @author Jeff Heaton * @version 1.2 */class SpiderDone {  /**   * The number of SpiderWorker object   * threads that are currently working   * on something.   */  private int activeThreads = 0;  /**   * This boolean keeps track of if   * the very first thread has started   * or not. This prevents this object   * from falsely reporting that the spider   * is done, just because the first thread   * has not yet started.   */  private boolean started = false;  /**   * This method can be called to block   * the current thread until the spider   * is done.   */  synchronized public void waitDone()  {    try {      while ( activeThreads>0 ) {        wait();      }    } catch ( InterruptedException e ) {    }  }  /**   * Called to wait for the first thread to   * start. Once this method returns the   * spidering process has begun.   */  synchronized public void waitBegin()  {    try {      while ( !started ) {        wait();      }    } catch ( InterruptedException e ) {    }  }  /**   * Called by a SpiderWorker object   * to indicate that it has begun   * working on a workload.   */  synchronized public void workerBegin()  {    activeThreads++;    started = true;    notify();  }  /**   * Called by a SpiderWorker object to   * indicate that it has completed a   * workload.   */  synchronized public void workerEnd()  {    activeThreads--;    notify();  }  /**   * Called to reset this object to   * its initial state.   */  synchronized public void reset()  {    activeThreads = 0;  }}