软件设计-命令模式

public class 命令模式 {
    public static void main(String[] args)
    {
        Tv tv=new Tv();
        Command onCommand=new OnCommand(tv);
        Command offCommand=new OffCommand(tv);

        Invoker invoker=new Invoker();
        invoker.setCommand(onCommand);
        invoker.call();

        invoker.setCommand(offCommand);
        invoker.call();
    }
}
class Invoker{
    private Command command;
    public void setCommand(Command command)
    {
        this.command=command;
    }
    public void call()
    {
        command.Execute();
    }
}
interface Command{
    public void Execute();
}
class OnCommand implements Command{
    private Tv tv;
    public OnCommand(Tv tv)
    {
        this.tv=tv;
    }
    @Override
    public void Execute(){
        tv.OnAction();
    }
}
class OffCommand implements Command{
    private Tv tv;
    public OffCommand(Tv tv)
    {
        this.tv=tv;
    }
    @Override
    public void Execute(){
        tv.OffAction();
    }
}
class Tv{
    public void OnAction(){
        System.out.println("电视机开机");
    }
    public void OffAction()
    {
        System.out.println("电视机关机了");
    }
}

运行结果