标签：设计 span 过程 poi 了解 vat name isa 好的
1.定义：又叫门面模式，提供了一个统一的接口，用来访问子系统中的一群接口；
外观模式定义了一个高层接口，让子系统更容易使用。
2.类型：结构型
3.适用场景：子系统越来越复杂，增加外观模式提供简单调用接口；
构建多层系统结构，利用外观对象作为每层的入口，简化层间调用。
4.优点：简化了调用过程，无需了解深入子系统，防止带来风险；
减少系统依赖、松散耦合；更好的划分访问层次；
符合迪米特法则，即最少知道原则。
5.缺点：增加子系统、扩展子系统行为容易引入风险；不符合开闭原则。
6.相关设计模式：中介者模式、单例模式、抽象工厂模式。
7.实例目录package
8.实例UML类图
9.代码
1 package com.geely.design.pattern.structural.facade; 2 3 public class PointsGift { 4 private String name; 5 6 public PointsGift(String name) { 7 this.name = name; 8 } 9 10 public String getName() { 11 return name; 12 } 13 }
1 package com.geely.design.pattern.structural.facade; 2 3 public class QualifyService { 4 public boolean isAvailable(PointsGift pointsGift){ 5 System.out.println("校验" + pointsGift.getName() + "积分资格通过，库存通过"); 6 return true; 7 } 8 }
1 package com.geely.design.pattern.structural.facade; 2 3 public class PointsPaymentService { 4 public boolean pay(PointsGift pointsGift){ 5 //扣减积分 6 System.out.println("支付"+pointsGift.getName()+" 积分成功"); 7 return true; 8 } 9 }
1 package com.geely.design.pattern.structural.facade; 2 3 public class ShippingService { 4 public String shipGift(PointsGift pointsGift){ 5 //物流系统的对接逻辑 6 System.out.println(pointsGift.getName() + "进入物流系统"); 7 String shippingOrderNo = "666"; 8 return shippingOrderNo; 9 } 10 }
1 package com.geely.design.pattern.structural.facade; 2 3 public class GiftExchangeService { 4 private QualifyService qualifyService; 5 private PointsPaymentService pointsPaymentService; 6 private ShippingService shippingService; 7 8 /*public void setQualifyService(QualifyService qualifyService) { 9 this.qualifyService = qualifyService; 10 } 11 12 public void setPointsPaymentService(PointsPaymentService pointsPaymentService) { 13 this.pointsPaymentService = pointsPaymentService; 14 } 15 16 public void setShippingService(ShippingService shippingService) { 17 this.shippingService = shippingService; 18 }*/ 19 20 public void giftExchange(PointsGift pointsGift){ 21 if(qualifyService.isAvailable(pointsGift)){ 22 if(pointsPaymentService.pay(pointsGift)){ 23 String shippingOrderNo = shippingService.shipGift(pointsGift); 24 System.out.println("物流系统下单成功，订单号是："+shippingOrderNo); 25 } 26 } 27 } 28 }
1 package com.geely.design.pattern.structural.facade; 2 3 public class Test { 4 public static void main(String[] args) { 5 PointsGift pointsGift = new PointsGift("T恤"); 6 GiftExchangeService giftExchangeService = new GiftExchangeService(); 7 /*giftExchangeService.setPointsPaymentService(new PointsPaymentService()); 8 giftExchangeService.setQualifyService(new QualifyService()); 9 giftExchangeService.setShippingService(new ShippingService());*/ 10 11 giftExchangeService.giftExchange(pointsGift); 12 } 13 }
标签：设计 span 过程 poi 了解 vat name isa 好的
原文地址：https://www.cnblogs.com/linbq1911/p/10229005.html
