设计模式笔记--适配器

举个栗子：
笔记本要充电，电压必须稳定在20V左右，家用电压是220V左右，直接接上大概会爆掉。这就需要电压适配器。

└── adapter
    ├── ChargerAdapter.java
    ├── Computer.java
    ├── ComputerNew.java
    └── Test.java

package com.xh.pattern.adapter;

/**
 * 没有适配器的电脑
 * Created by root on 3/15/18.
 */
public class Computer {

    /**
     * 充电
     *
     * @param voltage 电压
     */
    public void charge(int voltage) {
        if (18 <= voltage && voltage <= 20) {
            System.out.println("电压标准，正在充电...");
        } else {
            System.out.println("非标准电压，不能充电！");
        }

    }
}

package com.xh.pattern.adapter;

/**
 * 适配器
 * Created by root on 3/15/18.
 */
public class ChargerAdapter {

    /**
     * 变压
     *
     * @param voltage 电压
     */
    public int changeVoltage(int voltage) {
        System.out.println("电压是" + voltage + "V,改变为19V");
        return 19;

    }
}

package com.xh.pattern.adapter;

/**
 * Created by root on 3/15/18.
 */
public class ComputerNew extends Computer {

    private static ChargerAdapter chargerAdapter = new ChargerAdapter();

    /**
     * 充电
     *
     * @param voltage 电压
     */
    public void charge(int voltage) {
        voltage = chargerAdapter.changeVoltage(voltage);
        super.charge(voltage);
    }
}

package com.xh.pattern.adapter;

/**
 * Created by root on 3/15/18.
 */
public class Test {
    public static void main(String[] args) {
        Computer computer = new Computer();
        computer.charge(220);
        System.out.println("====================");
        computer = new ComputerNew();
        computer.charge(220);
    }
}

非标准电压，不能充电！
====================
电压是220V,改变为19V
电压标准，正在充电...