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