2. 结构型模式 (4) 外观模式

2. 结构型模式 (4) 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。

为子系统中的一组接口提供一个一致的界面，外观模式定义了一个高层接口，这个接口使得这一子系统更加容易使用。

1. 外观模式

package com.andrew.pattern0204.facade.model01;
public interface Shape {
    void draw();
}

package com.andrew.pattern0204.facade.model01;
public class Rectangle implements Shape {
    @Override
    public void draw() {
        System.out.println("Rectangle draw()");
    }
}

package com.andrew.pattern0204.facade.model01;
public class Square implements Shape {
    @Override
    public void draw() {
        System.out.println("Square draw()");
    }
}

package com.andrew.pattern0204.facade.model01;
public class Circle implements Shape {
    @Override
    public void draw() {
        System.out.println("Circle draw()");
    }
}

package com.andrew.pattern0204.facade.model01;
public class ShapeMaker {
    private Shape circle;
    private Shape rectangle;
    private Shape square;
    public ShapeMaker() {
        circle = new Circle();
        rectangle = new Rectangle();
        square = new Square();
    }
    public void drawCircle() {
        circle.draw();
    }
    public void drawRectangle() {
        rectangle.draw();
    }
    public void drawSquare() {
        square.draw();
    }
}

package com.andrew.pattern0204.facade.model01;
/**
 * 1. 外观模式
 * 
 * @author andrew
 * @date 2018/07/05
 */
public class Client {
    public static void main(String[] args) {
        ShapeMaker shapeMaker = new ShapeMaker();
        shapeMaker.drawCircle();
        shapeMaker.drawRectangle();
        shapeMaker.drawSquare();
    }
}
运行结果：
Circle draw()
Rectangle draw()
Square draw()