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。

代码实现

 

public interface Car {    public void run();}

 

public class Audi implements Car {    public void run() {        System.out.println("奥迪在跑!");    }}

public class Byd implements Car {    @Override    public void run() {        System.out.println("比亚迪再跑");    }}

public interface CarFactory {        Car createCar();}

public class AudiFactory implements CarFactory{    public Car createCar() {        return new Audi();    }}

public class BydFactory implements CarFactory{    public Car createCar() {        return new Byd();    }}

public class FactoryMethodTest {    @Test    public void test(){        Car audi = new AudiFactory().createCar();        audi.run();        System.out.println("-----------");        Car byd = new BydFactory().createCar();        byd.run();    }}