Java-马士兵设计模式学习笔记-观察者模式-模拟Awt Button

一、概述

Java 的Awt是 Observer模式，现用Java自己模拟awt中Button的运行机制

二、代码

1.Test.java

 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;

 public class Test {

     public static void main(String[] args) {
         Button b = new Button();
         b.addActionListener(new MyActionListener1());
         b.addActionListener(new MyActionListener2());
         b.buttonPress();
     }
 }

 class Button {

     //用List存放Listener
     private List<ActionListener> actionListeners = new ArrayList<ActionListener>();

     public void addActionListener(ActionListener l) {
         actionListeners.add(l);
     }

     public void buttonPress(){
         ActionEvent e = new ActionEvent(System.currentTimeMillis(), this);
         for (ActionListener l : actionListeners) {
             l.actionPerformed(e);
         }
     }
 }

 interface ActionListener {
     public void actionPerformed(ActionEvent e);
 }

 class MyActionListener1 implements ActionListener {

     @Override
     public void actionPerformed(ActionEvent e) {
         System.out.println("MyActionListener1");
         System.out.println("事件发生时间："+e.getTime()+" 事件源："+e.getSource());
     }

 }

 class MyActionListener2 implements ActionListener {

     @Override
     public void actionPerformed(ActionEvent e) {
         System.out.println("MyActionListener2");
         System.out.println("事件发生时间："+e.getTime()+" 事件源："+e.getSource());

     }

 }

 class ActionEvent {

     private long time;
     private Object source;

     public ActionEvent(long time, Object source) {
         this.time = time;
         this.source = source;
     }

     public Object getSource() {
         return source;
     }

     public String getTime() {
 //        DateFormat df = new SimpleDateFormat("dd:MM:yy:HH:mm:ss");
         DateFormat df = new SimpleDateFormat("yyyy:MM:dd---HH:mm:ss");
         return df.format(new Date(time));
     }

 }

三、运行结果