Java设计模式之命令模式详解

package com.example.designpatternsdemo.commandPattern;

/**
 * 命令接口
 */
public interface Command {
    public void execute();
}

package com.example.designpatternsdemo.commandPattern;

/**
 * 电灯
 */
public class Light {
	//on/off动作
    public void on(){
        System.out.println("开启电灯");
    }
    public void off(){
        System.out.println("关闭电灯");
    }
}

package com.example.designpatternsdemo.commandPattern;

/**
 * 电视
 */
public class TV {
    public void on(){
        System.out.println("开启电视");
    }

    public void off(){
        System.out.println("关闭电视");
    }
}

package com.example.designpatternsdemo.commandPattern;

/**
 * 开启电灯命令类
 */
public class LightOnCommand implements Command{
    //电灯对象
    private Light mLight;

    public LightOnCommand(Light light){
        this.mLight = light;
    }
    @Override
    public void execute() {
        mLight.on();
    }
}

package com.example.designpatternsdemo.commandPattern;

/**
 * 关闭电灯命令类
 */
public class LightOffCommand implements Command{
    //电灯对象
    private Light mLight;

    public LightOffCommand(Light light){
        this.mLight = light;
    }
    @Override
    public void execute() {
        mLight.off();
    }
}

package com.example.designpatternsdemo.commandPattern;

/**
 * 命令调用者
 * 遥控器
 */
public class RemoteControl {
    //保存开关命令对象的数组
    Command[] onCommands;
    Command[] offCommands;

    public RemoteControl(){
        //初始化数组
        onCommands = new Command[2];
        offCommands = new Command[2];
    }

    //存储命令
    public void setCommand(int index,Command onCommand,Command offCommand){
        onCommands[index] = onCommand;
        offCommands[index] = offCommand;
    }
    //开按钮
    public void onButtonPress(int btnIndex){
        onCommands[btnIndex].execute();
    }

    //关按钮
    public void offButtonPress(int btnIndex){
        offCommands[btnIndex].execute();
    }
}

package com.example.designpatternsdemo.commandPattern;

public class Client {

    public static void main(String[] args) {
        //创建电灯对象（命令接收者）
        Light myLight = new Light();
        //创建电灯开关命令对象
        LightOnCommand lightOnCommand = new LightOnCommand(myLight);
        LightOffCommand lightOffCommand = new LightOffCommand(myLight);
        //创建遥控器对象（命令调用者）
        RemoteControl remoteControl = new RemoteControl();
        //设置命令
        remoteControl.setCommand(0,lightOnCommand,lightOffCommand);
        //发起命令执行请求
        remoteControl.onButtonPress(0);
        remoteControl.offButtonPress(0);

        TV myTv = new TV();
        TvOnCommand tvOnCommand = new TvOnCommand(myTv);
        TvOffCommand tvOffCommand = new TvOffCommand(myTv);
        remoteControl.setCommand(1,tvOnCommand,tvOffCommand);
        remoteControl.onButtonPress(1);
        remoteControl.offButtonPress(1);
    }
}