设计模式--外观模式

 

代码说明：

package com.java.jikexueyuan.facademode.hometheater;
//爆米花
public class Popcorn {

    //单例模式，构造函数私有化
    private static Popcorn instance = null;

    private Popcorn() {

    }
    //单例模式创建实例
    public static Popcorn getInstance() {
        if (instance == null) {
            instance = new Popcorn();
        }

        return instance;
    }
    
    public void on() {
        System.out.println("Popcorn On");
    }

    public void off() {
        System.out.println("Popcorn Off");
    }

    public void pop() {
        System.out.println("Popcorn is popping");
    }
    
    
    
}

package com.java.jikexueyuan.facademode.hometheater;
//DVD播放器
public class DVDPlayer {

    private static DVDPlayer instance = null;

    private DVDPlayer() {

    }

    public static DVDPlayer getInstance() {
        if (instance == null) {
            instance = new DVDPlayer();
        }

        return instance;
    }
    
    public void on() {
        System.out.println("DVDPlayer On");
    }

    public void off() {
        System.out.println("DVDPlayer Off");
    }

    public void play() {
        System.out.println("DVDPlayer is playing");
    }
    
    public void pause() {
        System.out.println("DVDPlayer  pause");
    }
    
    public void setdvd() {
        System.out.println("DVDPlayer  is setting dvd");
    }
}

package com.java.jikexueyuan.facademode.hometheater;
//投影仪
public class Projector {
    private int size=5;

    private static Projector instance = null;

    private Projector() {

    }

    public static Projector getInstance() {
        if (instance == null) {
            instance = new Projector();
        }

        return instance;
    }
    
    public void on() {
        System.out.println("Projector On");
    }

    public void off() {
        System.out.println("Projector Off");
    }

    public void focus() {
        System.out.println("Popcorn is focus");
    }
    
    public void zoom(int size) {
        this.size=size;
        System.out.println("Popcorn zoom to"+size);
    }
    
}

package com.java.jikexueyuan.facademode.hometheater;
//屏幕
public class Screen {



    private static Screen instance = null;

    private Screen() {

    }

    public static Screen getInstance() {
        if (instance == null) {
            instance = new Screen();
        }

        return instance;
    }
    
    public void up() {
        System.out.println("Screen  up");
    }

    public void down() {
        System.out.println("Screen  down");
    }

    
    
    
    

}

package com.java.jikexueyuan.facademode.hometheater;
//音响
public class Stereo {

    private static Stereo instance = null;
    private int volume = 5;

    private Stereo() {

    }

    public static Stereo getInstance() {
        if (instance == null) {
            instance = new Stereo();
        }

        return instance;
    }

    public void on() {
        System.out.println("Stereo On");
    }

    public void off() {
        System.out.println("Stereo Off");
    }

    public void setVolume(int vol) {

        volume = vol;
        System.out.println("the volume of Stereo is set to  " + volume);
    }

    public void addVolume() {
        if (volume < 11) {
            volume++;
            setVolume(volume);
        }

    }

    public void subVolume() {
        if (volume > 0) {
            volume--;
            setVolume(volume);
        }

    }

}

package com.java.jikexueyuan.facademode.hometheater;
//灯光
public class TheaterLights {

    private static TheaterLights instance = null;

    private TheaterLights() {

    }

    public static TheaterLights getInstance() {
        if (instance == null) {
            instance = new TheaterLights();
        }

        return instance;
    }

    public void on() {
        System.out.println("TheaterLights On");
    }

    public void off() {
        System.out.println("TheaterLights Off");
    }

    public void dim(int d) {
        System.out.println("TheaterLights dim to " + d + "%");
    }

    public void bright() {
        dim(100);
        System.out.println("TheaterLights bright");
    }
}

package com.java.jikexueyuan.facademode.hometheater;
//外观模式--遥控器
public class HomeTheaterFacade {
    private TheaterLights mTheaterLights;
    private Popcorn mPopcorn;
    private Stereo mStereo;
    private Projector mProjector;
    private Screen mScreen;
    private DVDPlayer mDVDPlayer;
    //组合对象功能
    public HomeTheaterFacade() {
        mTheaterLights = TheaterLights.getInstance();
        mPopcorn = Popcorn.getInstance();
        mStereo = Stereo.getInstance();
        mProjector = Projector.getInstance();
        mScreen = Screen.getInstance();
        mDVDPlayer = DVDPlayer.getInstance();
    }

    public void ready() {
        mPopcorn.on();
        mPopcorn.pop();
        mScreen.down();
        mProjector.on();
        mStereo.on();
        mDVDPlayer.on();
        mDVDPlayer.setdvd();
        mTheaterLights.dim(10);
    }

    public void end() {
        mPopcorn.off();
        mTheaterLights.bright();
        mScreen.up();
        mProjector.off();
        mStereo.off();
        
        mDVDPlayer.setdvd();
        mDVDPlayer.off();
        
    }
    //单个对象功能
    public void play() {
        mDVDPlayer.play();
    }

    public void pause() {
        mDVDPlayer.pause();
    }
}

package com.java.jikexueyuan.facademode;

import com.java.jikexueyuan.facademode.hometheater.HomeTheaterFacade;


//代码测试
public class MainTest {
    public static void main(String[] args) {
        HomeTheaterFacade mHomeTheaterFacade=new HomeTheaterFacade();
        
        mHomeTheaterFacade.ready();
        mHomeTheaterFacade.play();
    }
}

 最少知识原则

最少知识原则：尽量减少对象之间的交互，只留几个“密友” 项目设计中就是不要让太多的类耦合在一起