产品类型接口：

public interface Car {}

产品工厂接口：

public interface ICarFactory {    public Car createCar();}

产品一：

public class BMW implements Car {
         public BMW(){        System.out.println("create BMW.");    }}

产品二：

public class Tesla implements Car {
         public Tesla() {        System.out.println("Create Tesla.");    }}

简单工厂：

public class CarFactory {    public static Car createCar(String type) {        switch (type) {        case "BMW":            return new BMW();        case "Tesla":            return new Tesla();        default:            return null;        }    }}

工厂方法一：

public class BMWFactory implements ICarFactory {
         @Override    public Car createCar() {        return new BMW();    }}

工厂方法二：

public class TeslaFactory implements ICarFactory {
         @Override    public Car createCar() {        return new Tesla();    }}

调用者：

public static void main(String[] args) {        // 简单工厂        Car bmw = CarFactory.createCar("BMW");        Car tesla = CarFactory.createCar("Tesla");        // 工厂方法        ICarFactory bmwFactory = new BMWFactory();        ICarFactory teslaFactory = new TeslaFactory();        Car bmw2 = bmwFactory.createCar();        Car tesla2 = teslaFactory.createCar();    }}