HeadFirst设计模式之门面模式

一、

1.The Facade Pattern provides a unifi ed interface to a set of interfaces in a subsytem. Facade defi nes a higher-level interface that makes the subsystem easier to use.

2.Facades and adapters may wrap multiple classes, but a facade’s intent is to simplify, while an adapter’s is to convert

the interface to something different.

3.

4.

二、

实现家庭影院

1.

 package headfirst.designpatterns.facade.hometheater;
 
 public class HomeTheaterFacade {
     Amplifier amp;
     Tuner tuner;
     DvdPlayer dvd;
     CdPlayer cd;
     Projector projector;
     TheaterLights lights;
     Screen screen;
     PopcornPopper popper;
 
     public HomeTheaterFacade(Amplifier amp,
                  Tuner tuner,
                  DvdPlayer dvd,
                  CdPlayer cd,
                  Projector projector,
                  Screen screen,
                  TheaterLights lights,
                  PopcornPopper popper) {
 
         this.amp = amp;
         this.tuner = tuner;
         this.dvd = dvd;
         this.cd = cd;
         this.projector = projector;
         this.screen = screen;
         this.lights = lights;
         this.popper = popper;
     }
 
     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.setSurroundSound();
         amp.setVolume(5);
         dvd.on();
         dvd.play(movie);
     }
 
     public void endMovie() {
         System.out.println("Shutting movie theater down...");
         popper.off();
         lights.on();
         screen.up();
         projector.off();
         amp.off();
         dvd.stop();
         dvd.eject();
         dvd.off();
     }
 
     public void listenToCd(String cdTitle) {
         System.out.println("Get ready for an audiopile experence...");
         lights.on();
         amp.on();
         amp.setVolume(5);
         amp.setCd(cd);
         amp.setStereoSound();
         cd.on();
         cd.play(cdTitle);
     }
 
     public void endCd() {
         System.out.println("Shutting down CD...");
         amp.off();
         amp.setCd(cd);
         cd.eject();
         cd.off();
     }
 
     public void listenToRadio(double frequency) {
         System.out.println("Tuning in the airwaves...");
         tuner.on();
         tuner.setFrequency(frequency);
         amp.on();
         amp.setVolume(5);
         amp.setTuner(tuner);
     }
 
     public void endRadio() {
         System.out.println("Shutting down the tuner...");
         tuner.off();
         amp.off();
     }
 }

2.

 package headfirst.designpatterns.facade.hometheater;
 
 public class HomeTheaterTestDrive {
     public static void main(String[] args) {
         Amplifier amp = new Amplifier("Top-O-Line Amplifier");
         Tuner tuner = new Tuner("Top-O-Line AM/FM Tuner", amp);
         DvdPlayer dvd = new DvdPlayer("Top-O-Line DVD Player", amp);
         CdPlayer cd = new CdPlayer("Top-O-Line CD Player", amp);
         Projector projector = new Projector("Top-O-Line Projector", dvd);
         TheaterLights lights = new TheaterLights("Theater Ceiling Lights");
         Screen screen = new Screen("Theater Screen");
         PopcornPopper popper = new PopcornPopper("Popcorn Popper");
 
         HomeTheaterFacade homeTheater =
                 new HomeTheaterFacade(amp, tuner, dvd, cd,
                         projector, screen, lights, popper);
 
         homeTheater.watchMovie("Raiders of the Lost Ark");
         homeTheater.endMovie();
     }
 }

3.

 package headfirst.designpatterns.facade.hometheater;
 
 public class Amplifier {
     String description;
     Tuner tuner;
     DvdPlayer dvd;
     CdPlayer cd;
 
     public Amplifier(String description) {
         this.description = description;
     }
 
     public void on() {
         System.out.println(description + " on");
     }
 
     public void off() {
         System.out.println(description + " off");
     }
 
     public void setStereoSound() {
         System.out.println(description + " stereo mode on");
     }
 
     public void setSurroundSound() {
         System.out.println(description + " surround sound on (5 speakers, 1 subwoofer)");
     }
 
     public void setVolume(int level) {
         System.out.println(description + " setting volume to " + level);
     }
 
     public void setTuner(Tuner tuner) {
         System.out.println(description + " setting tuner to " + dvd);
         this.tuner = tuner;
     }
 
     public void setDvd(DvdPlayer dvd) {
         System.out.println(description + " setting DVD player to " + dvd);
         this.dvd = dvd;
     }
 
     public void setCd(CdPlayer cd) {
         System.out.println(description + " setting CD player to " + cd);
         this.cd = cd;
     }
 
     public String toString() {
         return description;
     }
 }

4.

 package headfirst.designpatterns.facade.hometheater;
 
 public class Tuner {
     String description;
     Amplifier amplifier;
     double frequency;
 
     public Tuner(String description, Amplifier amplifier) {
         this.description = description;
     }
 
     public void on() {
         System.out.println(description + " on");
     }
 
     public void off() {
         System.out.println(description + " off");
     }
 
     public void setFrequency(double frequency) {
         System.out.println(description + " setting frequency to " + frequency);
         this.frequency = frequency;
     }
 
     public void setAm() {
         System.out.println(description + " setting AM mode");
     }
 
     public void setFm() {
         System.out.println(description + " setting FM mode");
     }
 
     public String toString() {
         return description;
     }
 }