Facade patten 读书笔记

阅读更多

提供了一个统一的接口，用来访问子系统中的一群接口。外观定义了一个高层接口，让子系统更容易使用。

1。当需要使用一个现有的类而其接口并不符合你的需求时，就使用适配器。
2。当需要简化并统一一个个很大的接口或者一群复杂的接口时，就使用外观。
3。适配器改变接口以符合客户的期望。
4。外观将客户从一个复杂的子系统中解耦。
5。实现一个适配器可能需要一番功夫，也可能不费功夫，视目标接口的大小与复杂度而定。
6。实现一个外观，需要将子系统组合进外观众，然后将工作委托给子系统执行。
7。适配器模式有两种形式：对象适配器和类适配器。类适配器需要用到多重继承。
8。你可以为一个子系统实现一个以上的外观。
9。适配器将一个对象包装起来以改变其接口：装饰者将一个对象包装起来以增加新的行为和责任，而外观将一群对象包装起来以便简化其接口。

package pattern;
public class HomeTheaterFacade {
 Amplifler amp = new Amplifler();
 Tuner tuner = new Tuner();
 DvdPlayer dvd = new DvdPlayer();
 CdPlayer cdPlayer = new CdPlayer();
 Projector projector = new Projector();
 TheaterLights lights = new TheaterLights();
 PopcomPopper popper = new PopcomPopper();
 Screen screen = new Screen();
 public HomeTheaterFacade(Amplifler amp, Tuner tuner, DvdPlayer dvd,
   CdPlayer cdPlayer, Projector projector, TheaterLights lights,
   PopcomPopper popper, Screen screen) {
  amp = amp;
  tuner = tuner;
  dvd = dvd;
  cdPlayer = cdPlayer;
  projector = projector;
  lights = lights;
  popper = popper;
  screen = screen;
 }
 public void WatchMovie(String movie) {
  System.out.println("Get ready to watch a movie ....");
  popper.on();
  popper.pop();
  lights.dim(10);
  screen.down();
  projector.on();
  projector.wideScreenMode();
  amp.on();
  amp.setDvd(dvd);
  amp.setSurroundSoud();
  amp.setVolume(5);
  dvd.on();
  dvd.play(movie);
 }
 public void EndMovie(String movie) {
  System.out.println("Shutting movie theater down ....");
  popper.off();
  lights.on();
  screen.up();
  projector.off();
  amp.off();
  dvd.stop();
  dvd.eject();
 }
}
class Amplifler {
 Tuner tuner;
 DvdPlayer dvdPlayer;
 CdPlayer cdPlayer;
 public void on() {
  System.out.println(" Amplifler on");
 }
 public void off() {
  System.out.println(" Amplifler off");
 }
 public void setCd(CdPlayer cdPlayer) {
  cdPlayer = cdPlayer;
 }
 public void setDvd(DvdPlayer dvdPlayer) {
  dvdPlayer = dvdPlayer;
 }
 public void setSurroundSoud() {
  System.out.println("Amplifler setSurroundSoud");
 }
 public void setTuner(Tuner tuner) {
  tuner = tuner;
 }
 public void setVolume(int vol) {
  System.out.println("Amplifler setVolume " + vol);
 }
 public String toString() {
  return "Amplifler";
 }
}
class Tuner {
 public void on() {
  System.out.println(" Tuner on");
 }
 public void off() {
  System.out.println(" Tuner off");
 }
 public void setAm() {
  System.out.println("Tuner setAm");
 }
 public void setFm() {
  System.out.println("Tuner setFm");
 }
 public void setFrequency() {
  System.out.println("Tuner setFrequency");
 }
 public String toString() {
  return "Tuner";
 }
}
class DvdPlayer {
 public void on() {
  System.out.println(" DvdPlayer on");
 }
 public void off() {
  System.out.println(" DvdPlayer off");
 }
 public void eject() {
  System.out.println(" DvdPlayer eject");
 }
 public void pause() {
  System.out.println(" DvdPlayer pause");
 }
 public void play(String movie) {
  System.out.println(" DvdPlayer play " + movie);
 }
 public void setSurroundAudio() {
  System.out.println(" DvdPlayer setSurroundAudio");
 }
 public void setTwoChannelAudio() {
  System.out.println(" DvdPlayer setTwoChannelAudio");
 }
 public void stop() {
  System.out.println(" DvdPlayer stop");
 }
}
class Screen {
 public void up() {
  System.out.println(" Screen up");
 }
 public void down() {
  System.out.println(" Screen down");
 }
 public String toString() {
  return "screen";
 }
}
class CdPlayer {
 public void on() {
  System.out.println(" CdPlayer on");
 }
 public void off() {
  System.out.println(" CdPlayer off");
 }
 public void eject() {
  System.out.println(" CdPlayer eject");
 }
 public void pause() {
  System.out.println(" CdPlayer pause");
 }
 public void play() {
  System.out.println(" CdPlayer play");
 }
 public void stop() {
  System.out.println(" CdPlayer stop");
 }
 public String toString() {
  return "CdPlayer";
 }
}
class Projector {
 DvdPlayer dvdPlayer;
 public void on() {
  System.out.println(" Projector on");
 }
 public void off() {
  System.out.println(" Projector off");
 }
 public void tvMode() {
  System.out.println(" Projector tvMode");
 }
 public void wideScreenMode() {
  System.out.println(" Projector wideScreenMode");
 }
 public String toString() {
  return "Projector";
 }
}
class PopcomPopper {
 public void on() {
  System.out.println(" PopcomPopper on");
 }
 public void off() {
  System.out.println(" PopcomPopper off");
 }
 public void pop() {
  System.out.println(" PopcomPopper pop");
 }
 public String toString() {
  return "PopcomPopper";
 }
}
class TheaterLights {
 public void on() {
  System.out.println(" TheaterLights on");
 }
 public void off() {
  System.out.println(" TheaterLights off");
 }
 public void dim(int dim) {
  System.out.println(" TheaterLights dim " + dim);
 }
 public String toString() {
  return "TheaterLights";
 }
}
 
package pattern;
public class HomeTheaterTestDrive {
 /**
  * @param args
  */
 public static void main(String[] args) {
  Amplifler amp = new Amplifler();
  Tuner tuner = new Tuner();
  DvdPlayer dvd = new DvdPlayer();
  CdPlayer cdPlayer = new CdPlayer();
  Projector projector = new Projector();
  TheaterLights lights = new TheaterLights();
  PopcomPopper popper = new PopcomPopper();
  Screen screen = new Screen();
  HomeTheaterFacade homeTheater = new HomeTheaterFacade(amp, tuner, dvd,
    cdPlayer, projector, lights, popper, screen);
  homeTheater.WatchMovie("TMD");
  homeTheater.EndMovie("TMD");
 }
}