外观模式Facade

  外观模式（Facade）：为子系统中的一组接口提供一个一致的界面，此模式定义了一个高层接口，

这个接口使得这一个子系统更加容易使用

  下面是类结构图：

   下面是源代码：

    SubSystemOne.java

package com.china_chenglong;

public class SubSystemOne {

public void sayOne(){

System.out.println("say one");

}

}

    SubSystemTwo.java

package com.china_chenglong;

public class SubSystemTwo {

public void sayTwo(){

System.out.println("say two");

}

}

    SubSystemThree.java package com.china_chenglong; public class SubSystemThree { public void sayThree(){ System.out.println("say three"); } }     Facade.java package com.china_chenglong; public class Facade { private SubSystemOne one; private SubSystemTwo two; private SubSystemThree three; public Facade(){ one = new SubSystemOne(); two = new SubSystemTwo(); three = new SubSystemThree(); } public void Say(){ one.sayOne(); two.sayTwo(); three.sayThree(); } }     MainClass.java package com.china_chenglong; public class MainClass { public static void main(String[] args) { Facade facade = new Facade(); facade.Say(); } }