从电视机的角度来看设计模式之命令模式

package command;

public interface Command {
    //延迟开机:
    void delay(String str);
    //暂停一下:
    void pause(String str);
    //马上开始:
    void start(String str);
}

package command;

public class ConcreteCommand implements Command{
    //持有执行者的引用
    private Receiver receiver;
    
    
    
    public ConcreteCommand(Receiver receiver) {
        super();
        this.receiver = receiver;
    }

    @Override
    public void delay(String str) {
        // TODO Auto-generated method stub
        str = "延迟了30秒!" + str;
        receiver.delay(str);
    }

    @Override
    public void pause(String str) {
        // TODO Auto-generated method stub
        str = "暂停!"+str;
        receiver.pause(str);
    }

    @Override
    public void start(String str) {
        // TODO Auto-generated method stub
        receiver.start(str);
    }

}

package command;

public class ConcreteCommand implements Command{
    //持有执行者的引用
    private Receiver receiver;
    
    
    
    public ConcreteCommand(Receiver receiver) {
        super();
        this.receiver = receiver;
    }

    @Override
    public void delay(String str) {
        // TODO Auto-generated method stub
        str = "延迟了30秒!" + str;
        receiver.delay(str);
    }

    @Override
    public void pause(String str) {
        // TODO Auto-generated method stub
        str = "暂停!"+str;
        receiver.pause(str);
    }

    @Override
    public void start(String str) {
        // TODO Auto-generated method stub
        receiver.start(str);
    }

}

package command;
//组合体,因为,只有它才知道我的参数给谁调用。如果，没有它就好像一台遥控器的红外线只能一台机器用一样.
public class Client {
    //遥控器
    private static Command command;
    //那台电视机
    private Receiver receiver;
        
    public Client(Receiver receiver) {
        super();
        this.receiver = receiver;
    }
    //对准哪台电视机
    public void assemble()
    {
        command = new ConcreteCommand(receiver);
    }
    

}

package command;
//真正的调用者
public class Invoker {
    //持有命令参数
    private Command command;

    public Invoker(Command command) {
        super();
        this.command = command;
    }
    
    public void runDelay(String str)
    {
        //调用了延迟,延迟多少秒由Command来决定了
        command.delay(str);
    }
    public void runPause(String str)
    {
        //调用了暂停
        command.pause(str);
    }
    public void runStart(String str)
    {
        //调用了开始
        command.start(str);
    }
}