command patten 读书笔记

1
。命令模式将发出请求的对象和执行请求的对象解耦。
2。在被解耦的两者之间是通过命令对象进行沟通的。命令对象封装了接受者和一个或者一组动作。
3。调用者通过调用命令对象的execute()发出请求，这会使得接受者的动作被调用。
4 。调用者可以接受命令当作参数，甚至在运行时动态进行。
5。命令可以支持撤销，做法是实现一个undo()方法来回到execute()被执行前的状态。
6。宏命令是命令的一种简单的延伸，允许调用多个命令。宏方法也可以支持撤销。
7。实际操作时，很常见使用“聪明”命令对象，也就是直接实现了请求，而不是将工作委托给接收者。
8。命令也可以用来实现日志和事物系统。

package pattern;
public interface Command {
 public void execute();
 public void undo();
}
class Light{
 public void on(){
  System.out.println("Light on");
 }
 public void off(){
  System.out.println("Light off");
 }
 public  Light(String ms){
  System.out.println(ms);
 }
 public  Light(){
 }
}
class TV {
 public void on(){
  System.out.println("TV on");
 }
 public void off(){
  System.out.println("TV off");
 }
 public  TV(String ms){
  System.out.println(ms);
 }
 public  TV(){
 }
}
class Hottub{
 public void on(){
  System.out.println("Hottub on");
 }
 public void off(){
  System.out.println("Hottub off");
 }
 public  Hottub(String ms){
  System.out.println(ms);
 }
 public  Hottub(){
 }
}
class CeilingFan{
 public static final int HIGH=3;
 public static final int  MEDIUM=2;
 public static final int LOW=1;
 public static final int OFF=0;
 String location;
 int speed;
 
 public void on(){  
 }
 public void off(){  
   speed=OFF;
 }
 public  CeilingFan(String ms){
  this.location=location;
  speed=OFF;
  System.out.println(ms);
 }
 public void high(){
  speed=HIGH;
 }
 public void medium(){
  speed=MEDIUM;
 }
 public void low(){
  speed=LOW;
 }
 public int getSpeed(){
  return speed;
 }
 public  CeilingFan(){
  
 }
}
class GarageDoor{
 public void up(){
  System.out.println("GarageDoor up ");
 }
 public void  down(){
  System.out.println("GarageDoor down");
 } 
 public void stop(){
  System.out.println("GarageDoor stop");
 }
 public void lightOn(){
  System.out.println("GarageDoor lightOn");
 }
 public void lightOff(){
  System.out.println("GarageDoor LightOff");
 }
 public GarageDoor(){}
 public GarageDoor(String ms){
  System.out.println(ms);
 }
}
class Stereo{
 public Stereo(){}
 public Stereo(String ms){
  System.out.println(ms);
 }
 int volume=0;
 public void on(){
  System.out.println("Stereo on");
 }
 public void off(){
  System.out.println("Stereo off");
 }
 public void setCD(){
  System.out.println("Stereo CD");
 }
 public void setVolume(int vol){
  volume= vol;
 }
}
class LightOnCommand implements Command{
 Light light;
 
 public LightOnCommand(Light light){
  this.light=light;
 }
 public void execute(){
  light.on();
 }
 public void undo(){
  light.off();
 }
 
}
class TVOnCommand implements Command{
 TV tv;
 
 public TVOnCommand(TV tv){
  this.tv=tv;
 }
 public void execute(){
  tv.on();
 }
 public void undo(){
  tv.off();
 }
 
}
class TVOffCommand implements Command{
 TV tv;
 
 public TVOffCommand(TV tv){
  this.tv=tv;
 }
 public void execute(){
  tv.off();
 }
 public void undo(){
  tv.on();
 }
 
}
class HottubOnCommand implements Command{
 Hottub hottub;
 
 public HottubOnCommand(Hottub hottub){
  this.hottub=hottub;
 }
 public void execute(){
  hottub.on();
 }
 public void undo(){
  hottub.off();
 }
 
}
class HottubOffCommand implements Command{
 Hottub hottub;
 
 public HottubOffCommand(Hottub hottub){
  this.hottub=hottub;
 }
 public void execute(){
  hottub.off();
 }
 public void undo(){
  hottub.on();
 }
 
}
class LightOffCommand implements Command{
 Light light;
 public LightOffCommand(Light light){
  this.light=light;
 }
 public void execute(){
  light.off();
 }
 public void undo(){
  light.on();
 }
}
class CeilingFanOnCommand implements Command{
 CeilingFan ceilingFan;
 public CeilingFanOnCommand(CeilingFan ceilingFan){
  this.ceilingFan=ceilingFan;
 }
 public void execute(){
  ceilingFan.on();
 }
 public void undo(){
  ceilingFan.off();
 }
}
class CeilingFanHighCommand implements Command{
 CeilingFan ceilingFan;
 int prevSpeed;
 public CeilingFanHighCommand(CeilingFan ceilingFan){
  this.ceilingFan=ceilingFan;
 }
 public void execute(){
  prevSpeed=ceilingFan.getSpeed();
  ceilingFan.high();
 }
 public void undo(){
  if(prevSpeed==CeilingFan.HIGH){
   ceilingFan.high();
  }
  if(prevSpeed==CeilingFan.MEDIUM){
   ceilingFan.medium();
  }
  if(prevSpeed==CeilingFan.LOW){
   ceilingFan.low();
  }
  if(prevSpeed==CeilingFan.OFF){
   ceilingFan.off();
  }
 }
}
class CeilingFanMediumCommand implements Command{
 CeilingFan ceilingFan;
 int prevSpeed;
 public CeilingFanMediumCommand(CeilingFan ceilingFan){
  this.ceilingFan=ceilingFan;
 }
 public void execute(){
  prevSpeed=ceilingFan.getSpeed();
  ceilingFan.medium();
 }
 public void undo(){
  if(prevSpeed==CeilingFan.HIGH){
   ceilingFan.high();
  }
  if(prevSpeed==CeilingFan.MEDIUM){
   ceilingFan.medium();
  }
  if(prevSpeed==CeilingFan.LOW){
   ceilingFan.low();
  }
  if(prevSpeed==CeilingFan.OFF){
   ceilingFan.off();
  }
 }
}
class CeilingFanLowCommand implements Command{
 CeilingFan ceilingFan;
 int prevSpeed;
 public CeilingFanLowCommand(CeilingFan ceilingFan){
  this.ceilingFan=ceilingFan;
 }
 public void execute(){
  prevSpeed=ceilingFan.getSpeed();
  ceilingFan.low();
 }
 public void undo(){
  if(prevSpeed==CeilingFan.HIGH){
   ceilingFan.high();
  }
  if(prevSpeed==CeilingFan.MEDIUM){
   ceilingFan.medium();
  }
  if(prevSpeed==CeilingFan.LOW){
   ceilingFan.low();
  }
  if(prevSpeed==CeilingFan.OFF){
   ceilingFan.off();
  }
 }
}
class CeilingFanOffCommand implements Command{
 CeilingFan ceilingFan;
 int prevSpeed;
 public CeilingFanOffCommand(CeilingFan ceilingFan){
  this.ceilingFan=ceilingFan;
 }
 public void execute(){
  prevSpeed=ceilingFan.getSpeed();
  ceilingFan.off();
 }
 public void undo(){
  if(prevSpeed==CeilingFan.HIGH){
   ceilingFan.high();
  }
  if(prevSpeed==CeilingFan.MEDIUM){
   ceilingFan.medium();
  }
  if(prevSpeed==CeilingFan.LOW){
   ceilingFan.low();
  }
  if(prevSpeed==CeilingFan.OFF){
   ceilingFan.off();
  }
 }
}
class GarageDoorUpCommand implements Command{
 GarageDoor garageDoor;
 public GarageDoorUpCommand(GarageDoor garageDoor){
  this.garageDoor=garageDoor;
 }
 public void execute(){
  garageDoor.up();
 }
 public void undo(){
  garageDoor.down();
 }
}
class GarageDoorDownCommand implements Command{
 GarageDoor garageDoor;
 public GarageDoorDownCommand(GarageDoor garageDoor){
  this.garageDoor=garageDoor;
 }
 public void execute(){
  garageDoor.down();
 }
 public void undo(){
  garageDoor.up();
 }
}
class StereOnCommand implements Command{
 Stereo stereo;
 public StereOnCommand(Stereo stereo){
  this.stereo=stereo;  
 }
 public void execute(){
  stereo.on();
 }
 public void undo(){
  stereo.off();
 }
}
class StereOnWithCDCommand implements Command{
 Stereo stereo;
 public StereOnWithCDCommand(Stereo stereo){
  this.stereo=stereo;  
 }
 public void execute(){
  stereo.on();
  stereo.setCD();
  stereo.setVolume(11);
 }
 public void undo(){
  stereo.off();
 }
}
class StereOffCommand implements Command{
 Stereo stereo;
 public StereOffCommand(Stereo stereo){
  this.stereo=stereo;  
 }
 public void execute(){
  stereo.off();
 }
 public void undo(){
  stereo.on();
  stereo.setCD();
  stereo.setVolume(11);
 }
}
class GarageDoorOpenCommand implements Command{
 GarageDoor garageDoor;
 public GarageDoorOpenCommand(GarageDoor garageDoor){
  this.garageDoor=garageDoor;
 }
 public void execute(){
  this.garageDoor.lightOn();
 }
 public void undo(){
  garageDoor.lightOff();
 }
}
class NoCommand implements Command{
 public void execute(){}
 public void undo(){}
}
class SimpleRemoteControl{
 Command slot;
 public SimpleRemoteControl(){}
 public void setCommand(Command command){
  slot=command;
 }
 public void bottomWasPressed(){
  slot.execute();
 }
}
class RemoteControl{
 Command[] onCommands;
 Command[] offCommands;
 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;
  }
 }
 public void setCommand(int slot,Command onCommand,Command offCommand){
  onCommands[slot]=onCommand;
  offCommands[slot]=offCommand;
 }
 public void onButtonWasPushed(int slot){
  onCommands[slot].execute();
 }
 public void offButtonWasPushed(int slot){
  offCommands[slot].execute();
 }
 public String toString(){
  StringBuffer stringBuff=new StringBuffer();
  stringBuff.append("\n------ Remote Control ------\n");
  for(int i=0; i<onCommands.length;i++){
   stringBuff.append("[slot "+i+"]"+onCommands[i].getClass().getName()+"  "+offCommands[i].getClass().getName() +"\n");
  }
  return stringBuff.toString();
 }
}
class RemoteControlWithUndo{
 Command[] onCommands;
 Command[] offCommands;
 Command undoCommand;
 public RemoteControlWithUndo(){
  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;
 }
 public void setCommand(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 stringBuff=new StringBuffer();
  stringBuff.append("\n------ Remote Control ------\n");
  for(int i=0; i<onCommands.length;i++){
   stringBuff.append("[slot "+i+"]"+onCommands[i].getClass().getName()+"  "+offCommands[i].getClass().getName() +"\n");
  }
  return stringBuff.toString();
 }
}
class MacroCommand implements Command{
 Command[] commands;
 public MacroCommand(Command[] commands){
  this.commands=commands;
 }
 public void execute(){
  for (int i=0;i<commands.length;i++){
   commands[i].execute();
  }
 }
 public void undo(){
  for (int i=0;i<commands.length;i++){
   commands[i].undo();
  }
 }
 
 
 
}
 
 
package pattern;
public class RemoteLoader {
 /**
  * @param args
  */
 public static void main(String[] args) {
  RemoteControlWithUndo remoteControlundo=new RemoteControlWithUndo();
  RemoteControl remoteControl=new RemoteControl();
  Light livingRoomLight=new Light("Living Room");
        Light kitchenLight=new Light("Kitchen");
        CeilingFan ceilingFan=new CeilingFan("Living Room");
        GarageDoor garageDoor=new GarageDoor("");
        Stereo stereo=new Stereo("Living Room");
        
        LightOnCommand livingRoomLightOn=new LightOnCommand(livingRoomLight);
        LightOffCommand livingRoomLightOff=new LightOffCommand(livingRoomLight);
        LightOnCommand kitchenLightOn=new LightOnCommand(kitchenLight);
        LightOffCommand kitchenLightOff=new LightOffCommand(kitchenLight);
        
        CeilingFanOnCommand ceilingFanOn=new CeilingFanOnCommand(ceilingFan);
        CeilingFanOffCommand ceilingFanOff=new CeilingFanOffCommand(ceilingFan);
        GarageDoorUpCommand garageDoorUp=new GarageDoorUpCommand(garageDoor);
        GarageDoorDownCommand garageDoorDown=new GarageDoorDownCommand(garageDoor);
        
        StereOnWithCDCommand stereoOnWithCD= new StereOnWithCDCommand(stereo);
        StereOffCommand stereoOff=new StereOffCommand(stereo);
        
        remoteControl.setCommand(0, livingRoomLightOn, livingRoomLightOff);
        remoteControl.setCommand(1, kitchenLightOn, kitchenLightOff);
        remoteControl.setCommand(2, ceilingFanOn, ceilingFanOff);
        remoteControl.setCommand(3, stereoOnWithCD, stereoOff);
        
        System.out.println(remoteControl);
        
        remoteControl.onButtonWasPushed(0);
        remoteControl.offButtonWasPushed(0);
        remoteControl.onButtonWasPushed(1);
        remoteControl.offButtonWasPushed(1);
        remoteControl.onButtonWasPushed(2);
        remoteControl.offButtonWasPushed(2);
        remoteControl.onButtonWasPushed(3);
        remoteControl.offButtonWasPushed(3);
     
        
        remoteControlundo.setCommand(0, livingRoomLightOn, livingRoomLightOff);
        remoteControlundo.onButtonWasPushed(0);
        remoteControlundo.offButtonWasPushed(0);
        System.out.println(remoteControlundo);
        remoteControlundo.undoButtonWasPushed();
        remoteControlundo.offButtonWasPushed(0);
        remoteControlundo.onButtonWasPushed(0);
        System.out.println(remoteControlundo);
        remoteControlundo.undoButtonWasPushed();
        
        System.out.println("ceilingFan high beging ......");
        CeilingFanMediumCommand ceilingFanMedium=new CeilingFanMediumCommand(ceilingFan);
        CeilingFanHighCommand ceilingFanHigh=new CeilingFanHighCommand(ceilingFan);
        remoteControlundo.setCommand(0, ceilingFanMedium, ceilingFanOff);
        remoteControlundo.setCommand(1, ceilingFanHigh, ceilingFanOff);
        
        remoteControlundo.onButtonWasPushed(0);
        remoteControlundo.offButtonWasPushed(0);
        System.out.println(remoteControlundo);
        remoteControlundo.undoButtonWasPushed();
        remoteControlundo.onButtonWasPushed(1);
        System.out.println(remoteControlundo);
        remoteControlundo.undoButtonWasPushed();
        
        System.out.println("hong command begin ......");
        Light light =new Light("Living Room");
        TV tv=new TV("Living Room");
        Hottub hottub=new Hottub();
        LightOnCommand lightOn=new LightOnCommand(light);
        StereOnCommand stereoOn=new StereOnCommand(stereo);
        TVOnCommand tvOn=new TVOnCommand(tv);
        HottubOnCommand hottubOn=new HottubOnCommand(hottub);
        LightOffCommand lightOff=new LightOffCommand(light);     
        TVOffCommand tvOff=new TVOffCommand(tv);
        HottubOffCommand hottubOff=new HottubOffCommand(hottub);
        Command[] partyOn={lightOn,stereoOn,tvOn,hottubOn};
        Command[] partyOff={lightOff,stereoOff,tvOff,hottubOff};
        MacroCommand partyOnMacro=new MacroCommand(partyOn);
        MacroCommand partyOffMacro=new MacroCommand(partyOff);
        remoteControlundo.setCommand(0, partyOnMacro, partyOffMacro);
        System.out.println(remoteControlundo);
        System.out.println("---- Pushing Macro On---");
        remoteControlundo.onButtonWasPushed(0);
        System.out.println("---- Pushing Macro Off---");
        remoteControlundo.offButtonWasPushed(0);
 }
}