工厂方法模式

概念

在对简单工厂的抽象时，如果我们将条件判断改由工厂的抽象，将工厂的选择交给调用端，那么久出现了工厂方法。
所以工厂方法是简单工厂的扩展；简单工厂是工厂方法的特例。

示例

产品抽象

interface Car {}
class Jeep implements Car {}
class Porsche implements Car {}

工厂抽象

interface Producer {
    Car produce();
}
class JeepProducer implements Producer {
    @Override public Car produce() { return new Jeep(); }
}
class PorscheProducer implements Producer {
    @Override public Car produce() { return new Porsche(); }
}

Client

public class Main {
    public static void main(String[] args) {
        Producer producer1 = new JeepProducer();
        Car jeep = producer1.produce();
        Producer producer2 = new PorscheProducer();
        Car porsche = producer2.produce();
    }
}