外观模式--Java实现

画类图

在计算机中，只要按下计算机的启动按钮，就能自动调用计算机内部的内存自检（Memory check()）、CPU的运行（run()）、硬盘的读取（HardDisk read()）、操作系统的载入（OS load()）等，如果某一个过程发生错误，那么整个系统都会启动失败！

具体代码实现

//MainFrame.java
package org.example.design009;

import org.example.design001.Main;

public class MainFrame {
    public MainFrame() {
        memory = new Memory();
        cpu = new CPU();
        hardDisk = new HardDisk();
        os = new OS();
    }

    private Memory memory;
    private CPU cpu;
    private HardDisk hardDisk;
    private OS os;


    public void start(){
        if(memory.check()&&cpu.run()&&hardDisk.read()&&os.load()){
            System.out.println("计算机启动成功！");
        }else{
            System.out.println("计算机启动失败！");
        }
    }

}

//Memory.java
package org.example.design009;

public class Memory {
    public boolean check(){
        System.out.println("内存读取成功！");
        return true;
    }
}

//CPU.java
package org.example.design009;

public class CPU {
    public boolean run(){
        System.out.println("CPU运行成功！");
        return true;
    }
}

//HardDisk.java
package org.example.design009;

public class HardDisk {
    public boolean read(){
        System.out.println("硬盘读取成功！");
        return true;
    }
}

//OS.java
package org.example.design009;

public class OS {
    public boolean load(){
        System.out.println("操作系统载入成功！");
        return true;
    }
}

//Client.java
package org.example.design009;

public class Client {
    public static void main(String[] args) {
        MainFrame mainFrame=new MainFrame();
        mainFrame.start();
    }
}