Java设计模式-----Factory Method模式

 源自：http://www.blogjava.net/flustar/archive/2007/11/29/factoryMethod.html

Factory Method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。FactoryMethod使一个类的实例化延迟到其子类。

例子：

public abstract class Ball {protected  abstract  void play();}public class Basketball extends Ball {protected void play() {System.out.println("play the basketball");}}public class Football extends Ball {protected void play() {System.out.println("play the football");}}public abstract class BallFactory {protected  abstract Ball makeBall();}public class BasketballFact extends BallFactory {protected Ball makeBall() {return new Basketball();}}public class FootballFact extends BallFactory {protected Ball makeBall() {return new Football();}}public class Client {public static void main(String[] args) {BallFactory ballFactory = new BasketballFact();Ball basketball = ballFactory.makeBall();basketball.play();ballFactory = new FootballFact();Ball football = ballFactory.makeBall();football.play();}}