更多的可以參考我的博客，也在陸續更新ing
http://www.hspweb.cn/

命令模式：將“請求”封裝成，對象，以便使用不同的請求、隊列或者日志來參數化其他對象。命令模式也支持可撤銷的操作。

下面例子為：音樂播放器的操作有：播放、上一首、下一首、暫停等功能，請用命令模式對該播放器的上述功能進行設計。

1.目錄

image

2.package command

①.Command.java

package command;
//實現命令接口
public interface Command {
    public void excute();
}

②.PlaySongCommand.java

package command;
import manufacturer.Player;

//實現一個播放器播放的命令 
public class PlaySongCommand implements Command{
    Player player;
    public PlaySongCommand(Player player){
        this.player=player;
    }
    public void excute() {
        // TODO Auto-generated method stub
        player.start();
    }

}

3. package control

①.SimpleRemoteControl.java

package control;
import command.Command;

//簡單的遙控器
public class SimpleRemoteControl {
    Command slot;
    public SimpleRemoteControl(){}
    public void setCommand (Command command){
        slot=command;
    }

    public void buttonWasPressed(){
        slot.excute();
    }
}

4.package manufacturer

①.Player.java

package manufacturer;
//播放器
public class Player {

    public void start() {
        // TODO Auto-generated method stub
        System.out.println("開始播放音樂");
    }
    public void stop(){
        System.out.println("停止播放音樂");
    }
    public void nextSong(){
        System.out.println("播放下一首音樂");
    }
    public void preSong(){
        System.out.println("播放上一首音樂");
    }

}

5.package test

①.test.java

package test;

import command.PlaySongCommand;

import manufacturer.Player;
import control.SimpleRemoteControl;

public class test {
    public static void main(String[] args) {
        SimpleRemoteControl remote=new SimpleRemoteControl();
        Player player=new Player();
        PlaySongCommand playsong=new PlaySongCommand(player);
        remote.setCommand(playsong);
        remote.buttonWasPressed();

    }
}

補充類圖

image