设计模式(17)-门面模式

定义
门面模式又称外观模式,旨在隐藏各子系统的具体细节,提供一个门面类统一对外交互.
外观类中一般不做任何业务逻辑的处理,只是做最简单的对外交互.

实例
1.接口

public interface IShape {
    public void draw();
}

2.接口实现类

public class Circle implements IShape{
    @Override
    public void draw() {
        System.out.println("圆形绘制中!!!");
    }
}

public class Rectangle implements IShape{
    @Override
    public void draw() {
        System.out.println("矩形绘制中!!!");
    }
}

public class Square implements IShape{
    @Override
    public void draw() {
        System.out.println("正方形绘制中!!!");
    }
}

3.门面类

public class ShapeFacade {
    private IShape circle;
    private IShape rectangle;
    private IShape square;

    public ShapeFacade(){
        circle = new Circle();
        rectangle = new Rectangle();
        square = new Square();
    }

    public void drawCircle(){
        this.circle.draw();
    }

    public void drawRectangle(){
        this.rectangle.draw();
    }

    public void drawSquare(){
        this.square.draw();
    }
}

3.运行

public class Client {
    public static void main(String[] args) {
        ShapeFacade facade = new ShapeFacade();
        facade.drawCircle();
        facade.drawRectangle();
        facade.drawSquare();
    }
}

结果:

圆形绘制中!!!
矩形绘制中!!!
正方形绘制中!!!