外观模式隐藏系统的复杂性，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。
例子：通过ShapeMaker简化Shape的创建。
1创建Shape类
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| package com.notejava.facade;
public interface Shape {
void draw();
}
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2.创建Circle类
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| package com.notejava.facade;
public class Circle implements Shape {
@Override
public void draw() {
}
}
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3.创建Rectangle类
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| package com.notejava.facade;
public class Rectangle implements Shape {
@Override
public void draw() {
}
}
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4.创建Square类
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| package com.notejava.facade;
public class Square implements Shape {
@Override
public void draw() {
}
}
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5.创建ShapeMaker类
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| package com.notejava.facade;
public class ShapeMaker {
protected Shape circle;
protected Shape rectangle;
protected Shape square;
public ShapeMaker() {
this.circle = new Circle();
this.rectangle = new Rectangle();
this.square = new Square();
}
public void drawCircle() {
}
public void drawRectangle() {
}
public void drawSquare() {
}
}
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6.创建Demo类
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| package com.notejava.facade;
public class Demo {
public static void main(String\[\] args) {
ShapeMaker shapeMaker = new ShapeMaker();
shapeMaker.drawCircle();
shapeMaker.drawRectangle();
shapeMaker.drawSquare();
}
}
|