package DesignPattern;public class CommondPattern {    //命令模式的要点：分离发令者，命令，与接令者    //将接令者对外暴露的接口包装成为一致的命令    //发令者拥有命令的实例，发令者调用命令实例，命令实例调用接令者接口从而实现命令动作    //优点：接令者的暴露在外的接口被一致化，增加命令功能，只需要继承Command接口，实现自定义功能，    // 完成了命令双向的解耦    //常见的命令模式：工作队列，日志请求    public static class Light{        private String name;        Light(String name){            this.name=name;        }        void on(){            System.out.println(name+" is on!");        }        void off(){            System.out.println(name+" is off!");        }    }    public interface Command{        void execute();        void undo();    }    public static class LightOnCommand implements Command{        Light light;        LightOnCommand(Light light){            this.light=light;        }        @Override        public void execute() {            light.on();        }        @Override        public void undo() {            light.off();        }    }    public static class LightOffCommand implements Command{        Light light;        LightOffCommand(Light light){            this.light=light;        }        @Override        public void execute() {            light.off();        }        @Override        public void undo() {            light.on();        }    }    //甚至可以实现宏命令    public static class MacroCommand implements Command{        Command[] commands;        MacroCommand(Command[] commands){            this.commands = commands;        }        @Override        public void execute() {            for(Command command:commands){                command.execute();            }        }        @Override        public void undo() {        }    }    public static class SimpleRemoteControl{        Command slot;        SimpleRemoteControl(){}        public void setCommand(Command slot) {            this.slot = slot;        }        public void buttonWasPressed(){            slot.execute();        }    }    public static class noCommand implements Command{        @Override        public void execute() {}        @Override        public void undo() {}    }    public static class RemoteControl{        Command[] onCommands;        Command[] offCommands;        Command undoCommand;        public RemoteControl(){            onCommands= new Command[7];            offCommands= new Command[7];            Command noCommand = new noCommand();            for(int i=0;i<7;i++){                onCommands[i]=noCommand;                offCommands[i]= noCommand;            }            undoCommand=noCommand;        }        /*        @Param slot 插口         */        public void setCommands(int slot,Command onCommand,Command offCommand){            onCommands[slot]=onCommand;            offCommands[slot]=offCommand;        }        public void onButtonWasPushed(int slot){            onCommands[slot].execute();            undoCommand=onCommands[slot];        }        public void offButtonWasPushed(int slot){            offCommands[slot].execute();            undoCommand=offCommands[slot];        }        public void undoButtonWasPushed(){            undoCommand.undo();        }        public String toString() {            StringBuffer stringBuffer = new StringBuffer();            stringBuffer.append("\n------Remote Control------\n");            for(int i=0;i