queue.java

用于串口通讯测试的工具软件。完全使用java语言编写。

/***********************************************************************
 * Module:  Queue.java
 * Author:  jzx
 * Purpose: Defines the Class Queue
 ***********************************************************************/

package com.zcsoft.comm;

import java.util.*;

/** <p>Title: 串口通信</p>
  * <p>Description: 队列 </p>
  * <p>Copyright: Copyright (c) 2002</p>
  * <p>Company: Zhicheng Software&Service Co. Ltd.</p>
  *
  * @author 蒋智湘
  * @version 1.0 */
public class Queue
{
	/** 队列中的项 */
	private Vector entries;
	/** 终止其它线程从队列中取出项 */
	private boolean stop;

	public Queue()
	{
		entries = new Vector();
	}

	/** @param entry */
	public synchronized void put(Object entry)
	{
		entries.addElement(entry);
		notify();
	}

	public synchronized void stop()
	{
		stop  = true;
		notify();
	}

	public synchronized Object pull()
	{
		while(isEmpty() && !stop)
		{
			try
			{
				wait();
			}
			catch (InterruptedException ex){}
			if(stop == true)
			{
				return null;
			}
		}
		return get();
	}

	public synchronized Object get()
	{
		Object object = peek();
		if(object != null)
		{
			entries.removeElementAt(0);
		}
		return object;
	}

	public Object peek()
	{
		return isEmpty()?null:entries.elementAt(0);
	}

	public boolean isEmpty()
	{
		return entries.isEmpty();
	}

	public int size()
	{
		return entries.size();
	}

	/**
	 * 判断队列中是否存在同指定对象相等的成员
	 * @param entry
	 * @return 如果存在，则返回true，否则返回false
	 */
	public boolean exists(Object entry)
	{
		return this.entries.indexOf(entry) != -1;
	}

	/** 枚举队列中的所有成员 */
	public Enumeration elements()
	{
		return entries.elements();
	}

}