简单工厂模式:

打开支付宝扫一扫 ，对着共享单车的二维码 ，就可以打开共享单车

用代码来展示就是:

public enum BikeCompany {	OFO,//ofo	HELLOBIKE//哈罗单车}

//共享单车都有各自的开锁声音public interface Bike {	public void unlock();}

//哈罗单车public class HelloBike implements Bike {	@Override	public void unlock() {		// TODO Auto-generated method stub		System.out.println("hello bike");	}	}

//小黄车public class OFO implements Bike{	@Override	public void unlock() {		// TODO Auto-generated method stub		System.out.println("滴滴滴");	}}

/** * 支付宝扫一扫 *  工厂 *  */public class AlipayRichScan {	public static Bike getBike(BikeCompany bikeCompany){		switch (bikeCompany) {			case OFO:				return new OFO();			case HELLOBIKE:				return new HelloBike();			default:				return null;		}	}}

运行一下程序

public class BikeTest {	public static void main(String[] args) {		Bike bike = AlipayRichScan.getBike(BikeCompany.HELLOBIKE);		bike.unlock();//开锁声音	}}

输出结果:

hello bike

UML类图:

如果摩拜单车也加入了支付宝,那得修改不少东西哦... 比如enum(BikeCompany)增加摩拜单车公司,

AlipayRichScan要增加case，有没有更好的办法呢?