结构性模式之---外观模式、MyBatis中Configuration的外观模式的使用分析

package java设计模式.Facade;

public class DVDPlayer {
    //使用单例模式, 使用饿汉式
    //类的内部创建对象
   private final static DVDPlayer instance=new DVDPlayer();
   private DVDPlayer(){

   }
   //向外提供一个静态公共方法
    public static DVDPlayer getInstance(){
       return instance;
    }
    //开启
    public void on() {
        System.out.println("DVD开始运行");
    }
    //关闭
    public void off() {
        System.out.println("DVD关闭");
    }
    //运行
    public void play() {
        System.out.println("DVD正在运行");
    }

    //DVD放完了
    public void pause() {
        System.out.println("DVD放完了");
    }



}

package java设计模式.Facade;
//爆米花机
public class Popcorn {
    private Popcorn(){

    }
    private final static Popcorn instance=new Popcorn();
    public static Popcorn getInstance(){
        return instance;
    }
    //爆米花机开机
    public void on() {
        System.out.println("爆米花机开机");
    }
    //爆米花机关机
    public void off() {
        System.out.println("爆米花机关机");
    }
    //爆米花机正在制作爆米花
    public void pop() {
        System.out.println("爆米花机正在制作爆米花");
    }

}

package java设计模式.Facade;

public class Projector {
    //创建投影机
    private static Projector instance = new Projector();

    public static Projector getInstance() {
        return instance;
    }
    //投影机开机
    public void on() {
        System.out.println("投影机开机");
    }
    //投影机关机
    public void off() {
        System.out.println("投影机关机");
    }
    //投影机正在运行
    public void focus() {
        System.out.println("投影机正在运行");
    }


}

package java设计模式.Facade;

public class Screen {
    //创建荧幕
    private static Screen instance = new Screen();

    public static Screen getInstance() {
        return instance;
    }

    //上升荧幕
    public void up() {
        System.out.println("上升荧幕");
    }
    //下降荧幕
    public void down() {
        System.out.println("下降荧幕");
    }

}

package java设计模式.Facade;

public class Stereo {
    //创建立体声机
    private static Stereo instance = new Stereo();

    public static Stereo getInstance() {
        return instance;
    }
    //立体声机开机
    public void on() {
        System.out.println("立体声机开机");
    }
    //立体声机关机
    public void off() {
        System.out.println("立体声机关机");
    }
    //立体声机正在运行
    public void up() {
        System.out.println("立体声机正在运行");
    }

}

package java设计模式.Facade;
//灯光
public class TheaterLight {
    //创建灯光
    private static TheaterLight instance = new TheaterLight();

    public static TheaterLight getInstance() {
        return instance;
    }
    //灯光开启
    public void on() {
        System.out.println("灯光开启");
    }
    //灯光关闭
    public void off() {
        System.out.println("灯光关闭");
    }
    //灯光调暗
    public void dim() {
        System.out.println("灯光调暗");
    }
    //灯光调亮
    public void bright() {
        System.out.println("灯光调亮");
    }

}

package java设计模式.Facade;
//外观类
public class HomeTheaterFacade {
    //定义各个子系统对象
    private TheaterLight theaterLight;
    private Popcorn popcorn;
    private Stereo stereo;
    private Projector projector;
    private Screen screen;
    private DVDPlayer dVDPlayer;


    //构造器
    public HomeTheaterFacade() {
//        super();
        this.theaterLight = TheaterLight.getInstance();
        this.popcorn = Popcorn.getInstance();
        this.stereo = Stereo.getInstance();
        this.projector = Projector.getInstance();
        this.screen = Screen.getInstance();
        this.dVDPlayer = DVDPlayer.getInstance();
    }

    //操作分成 4 步
    //电影院准备
    public void ready() {
        popcorn.on();
        popcorn.pop();
        screen.down();
        projector.on();
        stereo.on();
        dVDPlayer.on();
        theaterLight.dim();
    }
    //电影开始
    public void play() {
        dVDPlayer.play();
    }
    //电影结束
    public void pause() {
        dVDPlayer.pause();
    }
    //电影院关闭
    public void end() {
        popcorn.off();
        theaterLight.bright();
        screen.up();
        projector.off();
        stereo.off();
        dVDPlayer.off();
    }


}

package java设计模式.Facade;

public class Client {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        //这里直接调用。。 很麻烦
        HomeTheaterFacade homeTheaterFacade = new HomeTheaterFacade();
        //电影院准备
        homeTheaterFacade.ready();
        //电影院开始
        homeTheaterFacade.play();
        //电影院结束
        homeTheaterFacade.end();
    }
}

public MetaObject newMetaObject(Object object) {
return MetaObject.forObject(object, this.objectFactory, this.objectWrapperFactory, this.reflectorFactory);
}

public static MetaObject forObject(Object object, ObjectFactory objectFactory, ObjectWrapperFactory objectWrapperFactory, ReflectorFactory reflectorFactory) {
return object == null ? SystemMetaObject.NULL_META_OBJECT : new MetaObject(object, objectFactory, objectWrapperFactory, reflectorFactory);
}

private MetaObject(Object object, ObjectFactory objectFactory, ObjectWrapperFactory objectWrapperFactory, ReflectorFactory reflectorFactory) {
this.originalObject = object;
this.objectFactory = objectFactory;
this.objectWrapperFactory = objectWrapperFactory;
this.reflectorFactory = reflectorFactory;
if (object instanceof ObjectWrapper) {
this.objectWrapper = (ObjectWrapper)object;
} else if (objectWrapperFactory.hasWrapperFor(object)) {
this.objectWrapper = objectWrapperFactory.getWrapperFor(this, object);
} else if (object instanceof Map) {
this.objectWrapper = new MapWrapper(this, (Map)object);
} else if (object instanceof Collection) {
this.objectWrapper = new CollectionWrapper(this, (Collection)object);
} else {
this.objectWrapper = new BeanWrapper(this, object);
}

}