主要角色
- 外观
职责
有点像装饰器模式和适配器模式的意思。外观模式的作用是对外提供一个新的接口，而业务逻辑则使用已有的代码。
类图
类关系示意图
代码
public class GiftExchangeService {
private QualifyService qualifyService = new QualifyService();
private PointsPaymentService pointsPaymentService = new PointsPaymentService();
private ShippingService shippingService = new ShippingService();
public void giftExchange(PointsGift pointsGift){
if(qualifyService.isAvailable(pointsGift)){
//资格校验通过
if(pointsPaymentService.pay(pointsGift)){
//如果支付积分成功
String shippingOrderNo = shippingService.shipGift(pointsGift);
System.out.println("物流系统下单成功,订单号是:"+shippingOrderNo);
}
}
}
}
---
public class PointsPaymentService {
public boolean pay(PointsGift pointsGift){
//扣减积分
System.out.println("支付"+pointsGift.getName()+" 积分成功");
return true;
}
}
---
public class QualifyService {
public boolean isAvailable(PointsGift pointsGift){
System.out.println("校验"+pointsGift.getName()+" 积分资格通过,库存通过");
return true;
}
}
---
public class ShippingService {
public String shipGift(PointsGift pointsGift){
//物流系统的对接逻辑
System.out.println(pointsGift.getName()+"进入物流系统");
String shippingOrderNo = "666";
return shippingOrderNo;
}
}
---
public class PointsGift {
private String name;
public PointsGift(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
使用
public class Test {
public static void main(String[] args) {
PointsGift pointsGift = new PointsGift("T恤");
GiftExchangeService giftExchangeService = new GiftExchangeService();
giftExchangeService.giftExchange(pointsGift);
}
}
