结构模式－门面模式

门面模式：外部与一个子系统的通信必须通过一个统一的门面对象进行。

门面模式类似于适配器模式，但是门面模式并不包含具体的业务逻辑，门面模式是一个用来减少系统耦合，优化系统架构的接口

门面模式包括门面和子系统两个角色。门面模式提高了子系统的独立性和可移植性。

由于门面模式不包含具体的业务逻辑，这样的好处是子系统内部的逻辑修改了，不影响其他子系统的调用，对其他子系统是透明的。

 

客户端：

package com.javapatterns.facade.securityfacade;

public class Client
{
    private static SecurityFacade security = new SecurityFacade();

    public static void main(String[] args)
    {
		security.activate();
    }
}

 

门面：

package com.javapatterns.facade.securityfacade;

public class SecurityFacade
{
    /**
     * @directed*/
    private Camera camera1= new Camera(), camera2= new Camera();

    /**
     * @directed 
     */
    private Light light1 = new Light(), light2 = new Light(), light3 = new Light();

    /**
     * @directed*/
    private Sensor sensor = new Sensor();

    /**
     * @directed*/
    private Alarm alarm = new Alarm();

    public void activate()
    {
		camera1.turnOn();
		camera2.turnOn();

        light1.turnOn();
        light2.turnOn();
        light3.turnOn();

        sensor.activate();
        alarm.activate();
    }

    public void deactivate()
    {
		camera1.turnOff();
		camera2.turnOff();

        light1.turnOff();
        light2.turnOff();
        light3.turnOff();

        sensor.deactivate();
        alarm.deactivate();
    }

}

 

内部系统组建1

package com.javapatterns.facade.securityfacade;

public class Alarm
{
    public void activate()
    {
		System.out.println("Activating the alarm.");
    }

    public void deactivate()
    {
		System.out.println("Deactivating the alarm.");
    }

    public void ring()
    {
		System.out.println("Ring the alarm.");
    }

    public void stopRing()
    {
		System.out.println("Stop the alarm.");
    }
}

 

内部系统组建2

package com.javapatterns.facade.securityfacade;

public class Camera
{
    public void turnOn()
    {
		System.out.println("Turning on the camera.");
    }

    public void turnOff()
    {
		System.out.println("Turning off the camera.");
    }

    public void rotate(int degrees)
    {
		System.out.println("Rotating the camera by " + degrees + " degrees.");
    }
}

 内部系统组建3

package com.javapatterns.facade.securityfacade;

public class Light
{
    public void turnOn()
    {
		System.out.println("Turning on the light.");
    }

    public void turnOff()
    {
		System.out.println("Turning off the light.");
    }

    public void changeBulb()
    {
		System.out.println("Changing the light-bulb.");
    }
}

 

内部系统组建4

package com.javapatterns.facade.securityfacade;

public class Sensor
{
    public void activate()
    {
		System.out.println("Activating on the sensor.");
    }

    public void deactivate()
    {
		System.out.println("Deactivating on the sensor.");
    }

    public void trigger()
    {
		System.out.println("The sensor has been triggered.");
    }
}