thread15_3.java

很有用的课件

/**
 * FileName:Thread15_3
 * Description:
 * Copyright:    Copyright (c) 2002
 * Company:
 * @author:Liyunshan
 * @version 1.0
 */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


class ThreadFrame extends JFrame
{
	//定义控件
	JButton startButton;
	JButton pauseButton;
	JButton stopButton;
	JTextField textField;

	RandomNumber theThread;

	//类构建器
	public ThreadFrame()
	{
		super("Thread action");
		Container pane = getContentPane();
		textField = new JTextField(" ", 1);
		startButton = new JButton("Start");
		pauseButton = new JButton("Pause");
		stopButton = new JButton("Stop");

		JPanel paneUp = new JPanel();
		JPanel paneDown = new JPanel();

		theThread = new RandomNumber(textField);

		//添加控件
		pane.add(paneUp, "Center");
		pane.add(paneDown, "South");

		paneUp.add(textField);
		paneDown.add(startButton);
		paneDown.add(pauseButton);
		paneDown.add(stopButton);

		setSize(300, 100);						//设置窗体大小
		setVisible(true);						//设置窗体为可见

		//初始化控件状态
		textField.setEditable(false);
		pauseButton.setEnabled(false);
		stopButton.setEnabled(false);

		//关闭窗口事件
		addWindowListener(
			new WindowAdapter()
			{
				public void windowClosing(WindowEvent e)
				{
					System.exit(0);
				}
			}
		);

		//添加启动按钮事件，启动线程
		startButton.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent evt)
				{
					if (!theThread.isAlive())
					{
						theThread.start();
						theThread.isEnded = false;
						textField.setEditable(false);
						startButton.setEnabled(false);
						pauseButton.setEnabled(true);
						stopButton.setEnabled(true);
					}
				}
			}
		);

		//添加暂停/恢复按钮事件，暂停/恢复线程
		pauseButton.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent evt)
				{
					theThread.isSuspended = !theThread.isSuspended;
					if (theThread.isSuspended)  	//暂停线程
					{
						pauseButton.setText("Resume");
					}
					else	//恢复线程
					{
						pauseButton.setText("Pause");
						{
							synchronized(theThread)
							{
								theThread.notify();
							}
						}
					}
				}
			}
		);

		//添加终止按钮事件，终止线程
		stopButton.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent evt)
				{
					theThread.isEnded = true;
					startButton.setEnabled(false);
					pauseButton.setEnabled(false);
					stopButton.setEnabled(false);
				}
			}
		);
	}
}

class RandomNumber extends Thread
{
	JTextField textField;
	boolean isEnded;			//表示线程是否终止
	boolean isSuspended;		//表示线程是否暂停


	//构建器
	public RandomNumber(JTextField t)
	{
		textField = t;
		isEnded = false;
		isSuspended = false;
	}

	//线程体
	public synchronized void run()
	{
		while (!isEnded)	//如果isEnded为true，则退出循环，结束线程
		{
			try
			{
				if (!isSuspended)	//正常状态
				{
					int temp = (int) (Math.random() * 10);
					textField.setText("" + temp);
					sleep(100);
				}
				else	//暂停状态
				{
					wait();
				}
			}
			catch(InterruptedException e) {}
		}
	}
}

public class Thread15_3
{
	public static void main(String args[])
	{
		ThreadFrame frame = new ThreadFrame();
		frame.setVisible(true);
	}
}