java 简单工厂&抽象工厂

工厂模式：就是提供一个实例化对象的接口，让子类去决定实现哪个具体对象

1：简单工厂

public abstract class Person {

}

public class XiaoLi extends Person {
    public void eat() {
        System.out.println("小李吃饭");
    }
}

public class XiaoMing extends Person {
    public void eat() {
        System.out.println("小明吃饭");
    }
}

/**
 * 简单工厂
 */
public class SimpleFactory {
    public Person instance(String username) {
        if (username.equals("1")) {
            return new XiaoMing();
        } else if (username.equals("2")) {
            return new XiaoLi();
        }
        return null;
    }
}

public class SimpleTest {
    public static void main(String[] args) {
        SimpleFactory factory = new SimpleFactory();
        Person xiaoming = factory.instance("1");
        Person xiaoli = factory.instance("2");
        XiaoLi m = (XiaoLi) xiaoli;
        m.eat();
        XiaoMing l = (XiaoMing) xiaoming;
        l.eat();

    }
}
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2：抽象工厂

public abstract class Product {
}

public class MobilePhone extends Product {
    public void desc() {
        System.out.println("this is mobilephone");
    }
}

public class Pen extends Product {
    public void desc(){
        System.out.println("this is pen");
    }
}

/**
 * 抽象工厂-每个类别创建自己的工厂
 */
public abstract class Afactory {
    public abstract Product instance();
}

public class MobilePhoneFactory extends  Afactory {
    @Override
    public Product instance() {
        return new MobilePhone();
    }
}

public class PenFactory extends Afactory {
    @Override
    public Product instance() {
        return new Pen();
    }
}

/**
 * 抽象工厂模式测试
 * 工厂模式：提供一个实例化对象的接口，让子类去决定实例那个具体对象
 */
public class TestAbs {
    public static void main(String[] args) {
        Afactory penFactory = new PenFactory();
        Pen pen = (Pen) penFactory.instance();
        pen.desc();
        Afactory mobileFactory = new MobilePhoneFactory();
        MobilePhone mobilePhone = (MobilePhone) mobileFactory.instance();
        mobilePhone.desc();
    }
}