設計模式——適配器模式

場景

美國交流電插頭（2頭）沒法插到歐洲壁式插座（3孔）

解決方法是在中間環節用適配器轉化下搞定。

意圖

將一個藉口轉化成另外一個接口

舉例

代碼

#

package designpattern.adapter;

public interface AmericanPlug {
    public void desc();
    public void func();
}

#

package designpattern.adapter;

public interface EuropePlug {
    public void desc();
    public void func();
}

 

##

package designpattern.adapter;

public class AmericanPlugImpl implements AmericanPlug{
    public void desc() {
        System.out.println("American");
    }

    public void func()  {
        System.out.println("American two plug");
    }
}

##

package designpattern.adapter;

public class EuropePlugImpl implements EuropePlug{
    public void desc() {
        System.out.println("EuropePlug");
    }

    public void func() {
        System.out.println("EuropePlug three plug");
    }
}

 

###

package designpattern.adapter;

public class AmericanAdapter implements EuropePlug{
    AmericanPlug americanPlug;

    public AmericanAdapter(AmericanPlug americanPlug) {
        this.americanPlug = americanPlug;
    }

    public void desc() {
        americanPlug.desc();
    }

    public void func() {
        System.out.println("Before adapter");
        americanPlug.func();
        System.out.println("After adapter");
    }
}

測試

package designpattern.adapter;

public class Test {
    public static void main(String[] args) {
        System.out.println("AmericanPlug---------");
        AmericanPlug americanPlug = new AmericanPlugImpl();
        americanPlug.desc();
        americanPlug.func();


        System.out.println("\nEuropePlug---------");
        EuropePlug europePlug = new EuropePlugImpl();
        europePlug.desc();
        europePlug.func();

        System.out.println("\nAmericanAdapter---------");
        AmericanAdapter americanAdapter = new AmericanAdapter(americanPlug);
        americanAdapter.desc();
        americanAdapter.func();
    }
}

輸出

AmericanPlug---------
American
American two plug

EuropePlug---------
EuropePlug
EuropePlug three plug

AmericanAdapter---------
American
Before adapter
American two plug
After adapter

Process finished with exit code 0