《设计模式 系列》- 结构型模式 - 外观模式

模式定义

外观模式是软件工程中常用的一种软件设计模式。它为子系统中的一组接口提供一个统一的高层接口。这一接口使得子系统更加容易使用。

模式结构

Facade：外观角色

SubSystem：子系统角色

UML图

代码实现

ConcreteSystemA.java

public class ConcreteSystemA {
public void operation1() {
System.out.println("this is ConcreteSystemA");
}
}

ConcreteSystemB.java

public class ConcreteSystemB {
public void operation2() {
System.out.println("this is ConcreteSystemB");
}
}

ConcreteSystemC.java

public class ConcreteSystemC {
public void operation3() {
System.out.println("this is ConcreteSystemC");
}
}

Facade.java

public class Facade {
private ConcreteSystemA concreteSystemA;
private ConcreteSystemB concreteSystemB;
private ConcreteSystemC concreteSystemC;

public Facade() {
concreteSystemA = new ConcreteSystemA();
concreteSystemB = new ConcreteSystemB();
concreteSystemC = new ConcreteSystemC();
}

public void operation1() {
concreteSystemA.operation1();
}

public void operation2() {
concreteSystemB.operation2();
}

public void operation3() {
concreteSystemC.operation3();
}
}

Client.java

public class Client {
public static void main(String[] args) {
Facade facade = new Facade();
facade.operation1();
facade.operation2();
facade.operation3();
}
}

参考资料

http://www.cnblogs.com/zuoxiaolong/p/pattern12.html

http://hjxandhmr.github.io/2016/06/05/DesignPattern-Facade/