大话设计模式----外观模式

public class SubSystemOne {
    public void methodOne(){
        System.out.println("子系统方法一");
    }
}

public class SubSystemTwo {
    public void methodTwo(){
        System.out.println("子系统方法二");
    }
}

public class SubSystemThree {
    public void methodThree(){
        System.out.println("子系统方法三");
    }
}

public class SubSystemFour {
    public void methodFour (){
        System.out.println("子系统方法四");
    }
}

public class Facade {
    SubSystemOne subSystemOne;
    SubSystemTwo subSystemTwo;
    SubSystemThree subSystemThree;
    SubSystemFour subSystemFour;

    public Facade(){
        subSystemOne = new SubSystemOne();
        subSystemTwo = new SubSystemTwo();
        subSystemThree = new SubSystemThree();
        subSystemFour = new SubSystemFour();
    }

    public void methodA(){
        System.out.println("========methodA=========");
        subSystemOne.methodOne();
        subSystemTwo.methodTwo();
        subSystemFour.methodFour();
    }

    public void methodB(){
        System.out.println("=========methodB=========");
        subSystemTwo.methodTwo();
        subSystemThree.methodThree();
    }
}

public class Test {
    public static void main(String[] args) {
        Facade facade = new Facade();
        facade.methodA();
        facade.methodB();
    }

    /** result
     * ========methodA=========
     * 子系统方法一
     * 子系统方法二
     * 子系统方法四
     * =========methodB=========
     * 子系统方法二
     * 子系统方法三
     */
}