命令模式解决智能生活项目问题

• 实现方式
  

• 代码实现

package com.atguigu.command;
//创建命令接口
public interface Command {
	//执行动作(操作)
	public void execute();
	//撤销动作(操作)
	public void undo();
}

package com.atguigu.command;
public class LightReceiver {
	public void on() {
		System.out.println(" 电灯打开了.. ");
	}
	
	public void off() {
		System.out.println(" 电灯关闭了.. ");
	}
}

package com.atguigu.command;
public class LightOffCommand implements Command {

	// 聚合LightReceiver
	LightReceiver light;

	// 构造器
	public LightOffCommand(LightReceiver light) {
			super();
			this.light = light;
		}

	@Override
	public void execute() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		light.off();
	}

	@Override
	public void undo() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		light.on();
	}
}

package com.atguigu.command;
public class LightOnCommand implements Command {

	//聚合LightReceiver
	LightReceiver light;
	
	//构造器
	public LightOnCommand(LightReceiver light) {
		super();
		this.light = light;
	}
	
	@Override
	public void execute() {
		// TODO Auto-generated method stub
		//调用接收者的方法
		light.on();
	}
	
	@Override
	public void undo() {
		// TODO Auto-generated method stub
		//调用接收者的方法
		light.off();
	}

}

package com.atguigu.command;
/**
 * 没有任何命令，即空执行: 用于初始化每个按钮, 当调用空命令时，对象什么都不做
 * 其实，这样是一种设计模式, 可以省掉对空判断
 */
public class NoCommand implements Command {

	@Override
	public void execute() {
		// TODO Auto-generated method stub
	}

	@Override
	public void undo() {
		// TODO Auto-generated method stub
	}

}

package com.atguigu.command;
public class RemoteController {

	// 开 按钮的命令数组
	Command[] onCommands;
	Command[] offCommands;

	// 执行撤销的命令
	Command undoCommand;

	// 构造器，完成对按钮初始化

	public RemoteController() {

		onCommands = new Command[5];
		offCommands = new Command[5];

		for (int i = 0; i < 5; i++) {
			onCommands[i] = new NoCommand();
			offCommands[i] = new NoCommand();
		}
	}

	// 给我们的按钮设置你需要的命令
	public void setCommand(int no, Command onCommand, Command offCommand) {
		onCommands[no] = onCommand;
		offCommands[no] = offCommand;
	}

	// 按下开按钮
	public void onButtonWasPushed(int no) { // no 0
		// 找到你按下的开的按钮， 并调用对应方法
		onCommands[no].execute();
		// 记录这次的操作，用于撤销
		undoCommand = onCommands[no];

	}

	// 按下开按钮
	public void offButtonWasPushed(int no) { // no 0
		// 找到你按下的关的按钮， 并调用对应方法
		offCommands[no].execute();
		// 记录这次的操作，用于撤销
		undoCommand = offCommands[no];

	}
	
	// 按下撤销按钮
	public void undoButtonWasPushed() {
		undoCommand.undo();
	}

}

# 编写第2种家电
package com.atguigu.command;
public class TVReceiver {
	public void on() {
		System.out.println(" 电视机打开了.. ");
	}
	
	public void off() {
		System.out.println(" 电视机关闭了.. ");
	}
}

package com.atguigu.command;
public class TVOffCommand implements Command {

	// 聚合TVReceiver
	TVReceiver tv;

	// 构造器
	public TVOffCommand(TVReceiver tv) {
		super();
		this.tv = tv;
	}

	@Override
	public void execute() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		tv.off();
	}

	@Override
	public void undo() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		tv.on();
	}
}

package com.atguigu.command;
public class TVOnCommand implements Command {

	// 聚合TVReceiver
	TVReceiver tv;

	// 构造器
	public TVOnCommand(TVReceiver tv) {
		super();
		this.tv = tv;
	}

	@Override
	public void execute() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		tv.on();
	}

	@Override
	public void undo() {
		// TODO Auto-generated method stub
		// 调用接收者的方法
		tv.off();
	}
}

package com.atguigu.command;
public class Client {

	public static void main(String[] args) {
		//使用命令设计模式，完成通过遥控器，对电灯的操作
		//创建电灯的对象(接受者)
		LightReceiver lightReceiver = new LightReceiver();
		//创建电灯相关的开关命令
		LightOnCommand lightOnCommand = new LightOnCommand(lightReceiver);
		LightOffCommand lightOffCommand = new LightOffCommand(lightReceiver);
		//需要一个遥控器
		RemoteController remoteController = new RemoteController();
		//给我们的遥控器设置命令, 比如 no = 0 是电灯的开和关的操作
		remoteController.setCommand(0, lightOnCommand, lightOffCommand);
		System.out.println("--------按下灯的开按钮-----------");
		remoteController.onButtonWasPushed(0);
		System.out.println("--------按下灯的关按钮-----------");
		remoteController.offButtonWasPushed(0);
		System.out.println("--------按下撤销按钮-----------");
		remoteController.undoButtonWasPushed();
		
		System.out.println("=========使用遥控器操作电视机==========");
		TVReceiver tvReceiver = new TVReceiver();
		TVOffCommand tvOffCommand = new TVOffCommand(tvReceiver);
		TVOnCommand tvOnCommand = new TVOnCommand(tvReceiver);
		//给我们的遥控器设置命令, 比如 no = 1 是电视机的开和关的操作
		remoteController.setCommand(1, tvOnCommand, tvOffCommand);
		System.out.println("--------按下电视机的开按钮-----------");
		remoteController.onButtonWasPushed(1);
		System.out.println("--------按下电视机的关按钮-----------");
		remoteController.offButtonWasPushed(1);
		System.out.println("--------按下撤销按钮-----------");
		remoteController.undoButtonWasPushed();
	}

}