设计模式之外观模式

外观模式（Facade Pattern）隐藏系统的复杂性，并向客户端提供了一个客户端可以访问系统的接口。这种类型的设计模式属于结构型模式，它向现有的系统添加一个接口，来隐藏系统的复杂性。

这种模式涉及到一个单一的类，该类提供了客户端请求的简化方法和对现有系统类方法的委托调用。

抽象接口

/**
 * @Author: chuan.bai
 * @Description  脸的抽象类 包含 耳朵 鼻子 眼睛等
 * @Date: Created on 13:35 2021/3/26
 * @Modified By:
 */
public interface Face {
    //使用的抽象方法
    void  use();

}

具体每个抽象类具体的时间

/**
 * @Author: chuan.bai
 * @Description
 * @Date: Created on 13:37 2021/3/26
 * @Modified By:
 */
public class Eye implements Face{
    @Override
    public void use() {
        System.out.println("Eye.use");
    }
}

/**
 * @Author: chuan.bai
 * @Description
 * @Date: Created on 13:37 2021/3/26
 * @Modified By:
 */
public class Ear implements  Face{
    @Override
    public void use() {
        System.out.println("Ear.use");
    }
}

/**
 * @Author: chuan.bai
 * @Description
 * @Date: Created on 13:37 2021/3/26
 * @Modified By:
 */
public class Nose implements Face{
    @Override
    public void use() {
        System.out.println("Nose.use");
    }
}

外观类

/**
 * @Author: chuan.bai
 * @Description 外观类
 * @Date: Created on 13:40 2021/3/26
 * @Modified By:
 */
public class FaceMaker {

    private Face ear;
    private Face eye;
    private Face nose;

    public FaceMaker() {
        ear = new Ear();
        eye = new Eye();
        nose = new Nose();
    }

    public void useEar() {
        ear = new Ear();
        ear.use();
    }

    public void useEye() {
        eye = new Ear();
        eye.use();
    }

    public void useNose() {
        nose = new Nose();
        nose.use();
    }


}

客户端

/**
 * @Author: chuan.bai
 * @Description
 * @Date: Created on 13:43 2021/3/26
 * @Modified By:
 */
public class Client {

    public static void main(String[] args) {
        FaceMaker faceMaker = new FaceMaker();
        faceMaker.useEar();
        faceMaker.useNose();
        faceMaker.useEye();
    }
}

输出

Ear.use
Nose.use
Ear.use

Process finished with exit code 0