import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class ThreadDemo extends JFrame implements ActionListener{
	JPanel pnlMain;
	static JLabel lblMove;
	JButton btnControl;
	CurrentTime ct;
	public ThreadDemo(){
		super("繼承Thread類線程演示");
		pnlMain=new JPanel(new GridLayout(2,1));
		setContentPane(pnlMain);
		lblMove=new JLabel("");
		lblMove.setForeground(Color.RED);
		btnControl=new JButton("掛起");
		btnControl.addActionListener(this);
		pnlMain.add(lblMove);
		pnlMain.add(btnControl);
		ct=new CurrentTime();
		ct.start();
		setSize(250,150);
		setVisible(true);
		setResizable(false);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
	}
	public void actionPerformed(ActionEvent ae){
		if(ae.getActionCommand()=="掛起"){
			btnControl.setText("重啟");
			ct.suspend();
		}
		if(ae.getActionCommand()=="重啟"){
			btnControl.setText("掛起");
			ct.resume();	
		}
	}
	public static void main(String args[]){
		ThreadDemo td=new ThreadDemo();
	}
}

class CurrentTime extends Thread{
	Date dateDisplay;
	GregorianCalendar gcCalendar;
	String strTime;
	public CurrentTime(){}
	public void run(){
		while(true){
			displayTime();
			try{
				this.sleep(1000);
			}
			catch(InterruptedException e){JOptionPane.showMessageDialog(null,"線程中斷!");}
		}
	}
	public void displayTime(){
		//dateDisplay=new Date();
		gcCalendar=new GregorianCalendar();
		//gcCalendar.setTime(dateDisplay);
		strTime="當前時間:"+gcCalendar.get(Calendar.HOUR)+":"+gcCalendar.get(Calendar.MINUTE)+":"+gcCalendar.get(Calendar.SECOND);
		ThreadDemo.lblMove.setText(strTime);
	}
}