threaddemo.java

学习参考,java基本语法练习,包括一些常用的技巧

//继承Thread类线程演示
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.lang.*;
import java.util.*;
//通过继承Thread类创建线程
public class ThreadDemo extends JFrame implements ActionListener
{
    JPanel pnlMain;
    static JLabel lblMove;
    JButton btnControl;
    //声明一个显示当前时间的线程
    CurrentTime ct;
    public ThreadDemo()
    {
		super("继承Thread类线程演示");
    	pnlMain=new JPanel(new GridLayout(2,1));
    	setContentPane(pnlMain);
    	lblMove=new JLabel("");
    	lblMove.setFont(new Font("宋体",Font.BOLD,22));
    	lblMove.setForeground(Color.RED);
    	btnControl=new JButton("挂起");
    	btnControl.addActionListener(this);
    	pnlMain.add(lblMove);
    	pnlMain.add(btnControl);
    	//构造线程对象并让它处于运行状态
    	ct=new CurrentTime();
    	ct.start();
    	setSize(250,150);
    	setVisible(true);
    	setResizable(false);
    	setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
	//实现ActionListener接口必须实现的方法
	public void actionPerformed(ActionEvent ae)
	{
		if (ae.getActionCommand()=="挂起")
		{
			btnControl.setText("重启");
			ct.suspend();
		}
		if (ae.getActionCommand()=="重启")
		{
			btnControl.setText("挂起");
			ct.resume();
		}
	}
	public static void main(String args[])
	{
		ThreadDemo td=new ThreadDemo();
	}
}
//独立的一个显示当前时间的线程类
class CurrentTime extends Thread
{
   	Date dateDisplay;
	GregorianCalendar gcCalendar;
	String strTime;
	public CurrentTime(){}
    //继承Thread类必须实现的run方法
    public void run()
    {
		while(true)
		{
			displayTime();
			try
			{	this.sleep(1000);}
			catch(InterruptedException e)
			{	JOptionPane.showMessageDialog(null,"线程中断!");}
		}		
	}
	//显示当前日期和时间的函数
	public void displayTime()
	{
		dateDisplay=new Date();
		gcCalendar=new GregorianCalendar();
		//获得当前时间
		gcCalendar.setTime(dateDisplay);
		//从当前时间中提取日期段和时间段
		strTime="   当前时间:"+gcCalendar.get(Calendar.HOUR)+":"+gcCalendar.get(Calendar.MINUTE)+":"+gcCalendar.get(Calendar.SECOND);
		//显示当前日期和时间
		ThreadDemo.lblMove.setText(strTime);
	}
}