java design pattern - facade pattern

这个东西主要是为了提供一个统一的接口，然后为了解耦用的。 同时也同时也带来了代码的复杂度。
使得代码的流水线长，wrapper太多，实际干活的代码不好找。

usage in jvm:
in javax.faces.context, ExternalContext internally use ServletContext, HttpSession, 
HttpServletRequest, HttpServletResponse, etc, It allow the Faces API to be unaware of the nature 
of its containing application environment. 

code:

package facadepattern;

class C1{
    public int doSomething(int x){
        //return a int's cube
        return x*x*x;
    }
}

class C2{
    public int doAnotherThing(C1 c1, int x){
        //double the cube
        return 2*c1.doSomething(x);
    }
}

class C3{
    public int doMoreThing(C1 c1, C2 c2, int x){
        //multiply C1 and C2
        return c1.doSomething(x) * c2.doAnotherThing(c1, x);
    }
}

class Facade{
    public int cubeX(int x){
        C1 c1 =new C1();
        return c1.doSomething(x);
    }

    public int cubeXTimes2(int x){
        C1 c1 = new C1();
        C2 c2 = new C2();
        return c2.doAnotherThing(c1, x);
    }

    public int MultiplyBoth(int x){
        C1 c1 = new C1();
        C2 c2 = new C2();
        C3 c3 = new C3();
        return c3.doMoreThing(c1, c2, x);
    }
}

public class FacadePatternDemo {
    public static void main(String[] args){
        Facade fc= new Facade();

        int x= 3;
        System.out.println("Cube of x :"+fc.cubeX(x));
        System.out.println("Cube of x * times 2:"+fc.cubeXTimes2(x));
        System.out.println("multiply C1 and C2 :"+fc.MultiplyBoth(x));
    }
}

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最近发现在Vmware 上的Win2k8的虚拟机加了第二块ISCSI的硬盘后显示为offline. 
需要按照这个先来把硬盘online.