设计模式——工厂模式

经过简单工厂的学习，发现在创建对象的时候，还是需要进行判断，这个判断少的时候还好，如果太多了，在使用的时候，这个简单工厂类就显得有些臃肿。所以还有一种模式，工厂模式。

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public class Person {    private Ax ax;    public Person(Ax ax) {        this.ax = ax;    }    public void kanshu(){        ax.kanshu();    }    public void kanchai(){        ax.kanchai();    }}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public interface Ax {    public void kanshu();    public void kanchai();}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public class WoodAx implements Ax {    @Override    public void kanshu() {        System.out.println("我是木斧子，我来砍树");    }    @Override    public void kanchai() {        System.out.println("我是木斧子，我来砍柴");    }}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public class StealAx implements Ax {    @Override    public void kanshu() {        System.out.println("我是金斧子，我来砍树,我砍的好");    }    @Override    public void kanchai() {        System.out.println("我是金斧子，我来砍柴,我砍的快");    }}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public abstract class AxFactory {   public abstract Ax createAx();}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public class WoodAxFactory extends AxFactory{    @Override    public Ax createAx() {        return new WoodAx();    }}

package com.xueyoucto.xueyou;/** * Created by Administrator on 2016-07-05. */public class StealAxFactory extends AxFactory{    @Override    public Ax createAx() {        return new StealAx();    }}

package com.xueyoucto.xueyou;/** * Hello world! */public class App {    public static void main(String[] args) {        System.out.println("Hello World!");        int i = 3;        AxFactory af;        if (i == 1) {            af = new WoodAxFactory();        } else {            af = new StealAxFactory();        }        Person p = new Person(af.createAx());        p.kanchai();        p.kanshu();    }}

运行后的结果如下图：

我们看一下，这段代码：

        Person p = new Person(af.createAx());

直接能够从工厂产生斧子，不需要关注是什么斧子，只需要使用就可以了。如果需要特定的斧子，可以在上面进行判断，选择对应的工厂进行生产斧子。