工厂方法模式

工厂方法模式：定义一个用于创建对象的接口，让子类决定实例化哪一个类。工厂方法使一个类的实例化延迟到其子类。

简单工厂模式违背了"开放-封闭"原则(再添加控制类时在简单工厂类中要修改)，工厂方法模式在添加控制类时，再添加控制类对应的工厂，克服了简单工厂违背了"开放-封闭"原则。

Leifeng.java类

package factory;

public class Leifeng {
    public void sweep(){
        System.out.println("扫地");
    }
    public void wash(){
        System.out.println("洗衣");
    }
    public void buyRice(){
        System.out.println("买米");
    }

}

Undergraduate.java类

package factory;

public class Undergraduate extends Leifeng {

}

Volunteer.java类

package factory;

public class Volunteer extends Leifeng {

}

IFacory.java类

package factory;

public abstract class IFacory {
    public abstract Leifeng createLeifeng();
}

UndergraduateFactory.java类

package factory;

public class UndergraduateFactory extends IFacory {

    @Override
    public Leifeng createLeifeng() {
        Leifeng lf = new Leifeng();
        return lf;
    }

}

VolunteerFactory.java类

package factory;

public class VolunteerFactory extends IFacory {

    @Override
    public Leifeng createLeifeng() {
        Leifeng lf = new Volunteer();
        return lf;
    }

}

Business.java类

package factory;

public class Business {

    public static void main(String[] args) {
        IFacory factory = new UndergraduateFactory();
        Leifeng lf1 = factory.createLeifeng();
        Leifeng lf2 = factory.createLeifeng();
        Leifeng lf3 = factory.createLeifeng();
        lf1.buyRice();
        lf2.sweep();
        lf3.wash();
        IFacory vfactory = new VolunteerFactory();
        Leifeng vl1 = vfactory.createLeifeng();
        Leifeng vl2 = vfactory.createLeifeng();
        Leifeng vl3 = vfactory.createLeifeng();
        vl1.buyRice();
        vl2.wash();
        vl3.sweep();
    }

}