java时钟

一般实现形式

 1 package ares.present;
 2
 3 import java.awt.event.ActionEvent;
 4 import java.awt.event.ActionListener;
 5 import java.util.Date;
 6
 7 public class Printer implements ActionListener {
 8
 9     @Override
10     public void actionPerformed(ActionEvent e) {
11         Date date=new Date();
12         System.out.println(date);
13     }
14 }

 1 package ares.present;
 2
 3 import java.awt.event.ActionListener;
 4 import javax.swing.JOptionPane;
 5 import javax.swing.Timer;
 6
 7 public class Main {
 8
 9     public static void main(String[] args) {
10        ActionListener listener= new Printer();
11        Timer timer=new Timer(1000,listener);
12        timer.start();
13        JOptionPane.showMessageDialog(null, "Quit");
14        System.exit(0);
15     }
16 }

升级版（匿名内部类）

 1 package ares.present;
 2
 3 import java.awt.event.ActionEvent;
 4 import java.awt.event.ActionListener;
 5 import java.util.Date;
 6 import javax.swing.JOptionPane;
 7 import javax.swing.Timer;
 8
 9 public class Main {
10
11     public static void main(String[] args) {
12         ActionListener listener=new ActionListener() {
13
14             @Override
15             public void actionPerformed(ActionEvent e) {
16                Date date=new Date();
17                System.out.println(date);
18             }
19         };
20
21         Timer timer=new Timer(1000,listener);
22         timer.start();
23         JOptionPane.showMessageDialog(null, "Quit");
24         System.exit(0);
25     }
26 }