├── LICENSE ├── README.md ├── READMEIMG ├── 211690962797_.pic.jpg ├── Project-Name.png ├── image（1）.png └── image（2）.png ├── pom.xml └── src └── main ├── java └── com │ └── gch │ └── discount │ ├── core │ ├── aware │ │ └── CalculatorRouter.java │ ├── discount │ │ ├── Calculator.java │ │ └── impl │ │ │ └── AbstractCalculator.java │ ├── enums │ │ └── GroupRelation.java │ ├── model │ │ ├── common │ │ │ ├── CalcResult.java │ │ │ ├── CalcStage.java │ │ │ ├── CalcState.java │ │ │ ├── DiscountConfig.java │ │ │ ├── DiscountContext.java │ │ │ ├── DiscountGroup.java │ │ │ ├── DiscountWrapper.java │ │ │ └── Item.java │ │ └── goods │ │ │ ├── GoodsInfo.java │ │ │ └── GoodsItem.java │ ├── permutation │ │ └── Permutation.java │ ├── precompute │ │ ├── PreCompute.java │ │ └── PreComputeHolder.java │ └── utils │ │ ├── DiscountGroupUtil.java │ │ ├── IdGenerator.java │ │ └── LimitingUtil.java │ └── demo │ ├── App.java │ └── biz │ ├── Flowable.java │ ├── TestController.java │ ├── calc │ ├── ManjianCalc.java │ └── ZhekouCalc.java │ ├── constant │ └── Constant.java │ └── precompute │ └── PreGroupBy.java └── resources └── calculator-core.properties /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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13 | 14 | ## 轻量级算法驱动优惠叠加器 15 | 16 | #### RT： 17 | 18 | 19 | 20 | #### 背景： 21 | 22 | 优惠是推动消费者转化的关键因素，它在激发用户消费行为上起着核心作用。目前市场上的优惠策略主要涵盖了各种活动（例如拼多多的“砍一刀”，天猫农场的互动，新用户的首次购买，复购，积分等）和优惠券（如折扣券，代金券，商品券，买一赠一等）。然而，这些复杂的优惠规则使得用户在计算优惠叠加的顺序时感到困扰。这可能导致用户在面对多重优惠时降低购买商品的欲望，尤其是当他们参与了多个活动并持有多个优惠券时，这种情况更为明显。 23 | 24 | 优惠的计算顺序可以分为平行式和渐进式，其中平行式优惠之间没有相互依赖关系，而渐进式优惠之间则存在依赖关系，即下一个优惠的触发取决于上一个优惠的实施结果。 25 | 26 | 设想小晴消费了100元，她手头有一张7折优惠券和一张满100元减30元的优惠券。这两个优惠券的使用顺序可能会产生不同的效果，则这2个优惠券的使用顺序有以下两种情况： 27 | 28 | 29 | 30 | `OnePRO`采用了一系列新颖的算法，实现了高效求解优惠排列的最优解。 31 | 32 | 33 | 34 | #### 核心计算类 Permutation<T extends GoodsItem> 35 | 36 | `Permutation`是一个重要的抽象类，作为`OnePRO`的核心，它采用了多种优化策略来确保高性能，这些策略的运用旨在提升计算效率和降低资源消耗，这些策略包括： 37 | 38 | - 预存的排列数结果集 39 | 40 | 之所以采用这种设计，是因为在业务场景中，我们需要频繁进行排列计算。对于给定长度的序列，其排列结果是固定的。在`Permutation`类中，`PERMUTATIONS`属性存储了7以内的排列数结果集。由于这里使用了`Byte`来存储数据，因此占用的内存空间非常小，这有助于提高性能并降低内存消耗。 41 | 42 | ```Java 43 | private final static Map>> PERMUTATIONS = Maps.newHashMap(); 44 | 45 | ``` 46 | 这个动作在类加载完成时执行，如果觉得7不合适，对7不满意，可以通过调整`SUPPORTEDSIZE`的大小来满足业务和性能的需求。 47 | 48 | 我们在实现中经过测试和调整，确定了7是一个相对平衡的参数，它兼顾了业务与性能，当然，根据实际需求，大家可以根据自己的情况来调整这个参数。 49 | 50 | ```Java 51 | public final static int SUPPORTEDSIZE = 7; 52 | 53 | static{ 54 | //前置计算 1-SUPPORTEDSIZE 之间所有排列组合 55 | for(byte i=1;i<=SUPPORTEDSIZE;i++){ 56 | PERMUTATIONS.put((int)i,Collections2.permutations(IntStream.range(0,i).boxed().map(x->(byte)x.intValue()).collect(Collectors.toList()))); 57 | } 58 | } 59 | 60 | ``` 61 | 62 | - $A_n^3$级别缓存 63 | 64 | 相对于传统的`Key-Value`结构，解决 $A_n^n$问题的缓存需要进行特殊设计，对于一个优惠集合而言， $A_n^3$意味着需要缓存*n*×(*n*−1)×(*n*−2)条数据。当n=7时，需要缓存210条数据。为了在内存大小和缓存带来的性能收益之间取得平衡， $A_n^3$是最合适的级别。 65 | 66 | `Permutation`类通过其成员变量`cache`实现了高性能缓存。 67 | 68 | ```Java 69 | private final Map> cache = Maps.newHashMap(); 70 | ``` 71 | 你或许已经注意到，`cache`的键值使用的是`Integer`类型。在大多数情况下，我们更倾向于使用`String`类型，但在需要进行大量计算的场景中，比如在万次计算的场景下，String字符串的拼接却成了性能瓶颈。 72 | 73 | 为了实现高性能的键生成，`Permutation`采用了独特的方法。它通过位移对`Byte`数组的前三个字节进行扰动，以确保每个键的唯一性，同时提升性能。 74 | 75 | ```Java 76 | private static Integer calcKey(List a){ 77 | return a.size()>=3?(a.get(0) << 6)+ (a.get(1) << 3) + a.get(2):0; 78 | } 79 | ``` 80 | 81 | `Permutation`提供了保存点来实现 $A_n^3$ 级别缓存，`CalcState` 记录了计算到第3步的状态，包括当前订单优惠金额和计算过程、已享用优惠的商品等，这些属性的保存和回放`Permutation`已经帮你做好了，`Permutation`额外提供了抽象的保存和回放方法来满足你的个性化诉求。 82 | 83 | ```Java 84 | /** 85 | * 业务将状态记录到保存点 86 | * @param state 保存点对象 87 | */ 88 | protected abstract void makeSnapshot(CalcState state,DiscountContext context); 89 | 90 | /** 91 | * 业务返回保存点状态 92 | * @param state 保存点对象 93 | */ 94 | protected abstract void backToSnapshot(CalcState state,DiscountContext context); 95 | ``` 96 | 97 | 在优惠计算中，存在一个优先级规则，即优惠计算是有优先级的，需要确保属性`calculateGroup`值较小的优惠先行计算。当发生`backToSnapshot`时，我们需要额外检查缓存中最后一个优惠与当前正准备要计算的优惠之间的关系，如果不满足特定条件，则直接终止计算，直接跳出。而`checkIfWakeUpJump`方法会在缓存被使用后立即判断是否需要继续下去。 98 | 99 | #### 上下文类 DiscountContext<T extends GoodsItem> 100 | 101 | `DiscountContext`是上下文，也是`Permutation`的成员变量，`DiscountContext`同样包含很多优化策略： 102 | 103 | - CalcStage数组 104 | 105 | 在变更最频繁也是最重要的计算步骤对象`CalcStage`使用数组存储，该数组随着上下文创建而创建，在`Permutation`中使用 106 | 107 | ```Java 108 | Arrays.fill(arr,null); 109 | ``` 110 | 111 | 将该数组清空并让它投入下一次计算，这样一次全排列过程中，数组只会被创建一次，避免了频繁创建数组带来的性能损耗。 112 | 113 | - 预计算 114 | 115 | `DiscountContext`的初始化是通过静态的`create`方法完成的，该方法将商品与优惠绑定在一起，同时执行一些用户自定义的逻辑，我们称之为“预计算”，预计算的结果被保存在`DiscountContext`的`preCompute`属性中，以便在后续的计算中直接取用，这种方法避免了在后续的高速迭代中重复执行相同的操作，如商品分组和、求和等，从而提高了计算效率。 116 | 117 | #### 预计算 PreCompute<T extends GoodsItem> 118 | 119 | 预计算提供了接口，要使用预计算首先需要实现PreCompute接口 120 | 121 | ```Java 122 | public interface PreCompute { 123 | /** 124 | * 判断符合条件的活动类型，符合才会执行preComputeItems 125 | */ 126 | Set matchTypes(); 127 | 128 | /** 129 | * 对商品做一些复杂集合操作 130 | * @param items 当前参与优惠的商品 131 | * @param discount 当前优惠 132 | * @param preCompute 存储计算的结果 133 | */ 134 | void preComputeItems(List items, DiscountWrapper discount, Map preCompute); 135 | } 136 | ``` 137 | 138 | 此外需要在资源目录下建立`calculator-core.properties`文件，配置内容如下 139 | 140 | ```Java 141 | precompute.path=你要扫描的包 142 | ``` 143 | `PreComputeHolder`将处理所有的`PreCompute`实现类，只有`matchTypes`匹配的情况下，才会执行`preComputeItems`方法。 144 | 145 | ```Java 146 | public class PreComputeHolder { 147 | public static Set COMPUTES= Sets.newHashSet(); 148 | private final static String PATH = "precompute.path"; 149 | 150 | static{ 151 | Properties properties = new Properties(); 152 | try { 153 | properties = PropertiesLoaderUtils.loadProperties(new FileSystemResource(Objects.requireNonNull(PreComputeHolder.class.getClassLoader().getResource("calculator-core.properties")).getPath())); 154 | } catch (Exception ignore) { 155 | } 156 | String path = properties.getProperty(PATH); 157 | if(StringUtils.isNotBlank(path)){ 158 | Reflections reflections = new Reflections(path); 159 | Set> subTypes = reflections.getSubTypesOf(PreCompute.class); 160 | for(Class clazz:subTypes){ 161 | try { 162 | COMPUTES.add(clazz.newInstance()); 163 | } catch (Exception ignore) { 164 | } 165 | } 166 | } 167 | } 168 | } 169 | ``` 170 | 171 | #### 计算器 Calculator 172 | 173 | `Calculator`是单个优惠的计算接口（即用于优惠计算的接口），它其中定义了一个`calcWarp`方法，负责具体的优惠计算逻辑，但由于`calcWarp`需要承担一些内部的事情，需要处理一些内部细节，因此为了简化使用者的开发工作，我们提供了一个抽象类`AbstractCalculator`，它实现了`calcWarp`方法，并最终暴露了一个更简单更直观的`calc`方法供使用者使用。 174 | 175 | `AbstractCalculator`的内容如下，在`AbstractCalculator`中，`calcWarp`方法负责创建`CalcStage`对象，维护`CalcStage`数组等内部工作，这些细节对于使用者来说是透明的，他们只需要关注并实现`calc`方法即可。 176 | 177 | ```Java 178 | public abstract class AbstractCalculator implements Calculator { 179 | public long calcWarp(DiscountContext context, DiscountWrapper discountWrapper, Map records, byte idx, int i) { 180 | CalcStage stage = new CalcStage(); 181 | CalcResult cr = context.getCalcResult(); 182 | long price= cr.getCurPrice(); 183 | stage.setBeforeCalcPrice(price); 184 | price = calc(context, discountWrapper,records, price, stage); 185 | if(price<0){ 186 | return price; 187 | } 188 | stage.setAfterCalcPrice(price); 189 | stage.setIndex(idx); 190 | stage.setStageType(discountWrapper.getType()); 191 | cr.setCurPrice(price); 192 | if(stage.getBeforeCalcPrice()>stage.getAfterCalcPrice()) { 193 | cr.getCurStages()[i] = stage; 194 | } 195 | return price; 196 | } 197 | 198 | /** 199 | * 返回该优惠下的最终要支付的金额,若不符合则返回 prevStagePrice 200 | * @param context 上下文 201 | * @param discountWrapper 优惠信息 202 | * @param records 记录享受过优惠的单品，key是calculateId，这里只提供容器，添加和判断规则由使用者自行决定 203 | * @param prevStagePrice 上一步计算的订单的价格 204 | * @param curStage 当前stage 205 | * @return 206 | */ 207 | public abstract long calc(DiscountContext context, DiscountWrapper discountWrapper, Map records, long prevStagePrice, CalcStage curStage); 208 | 209 | } 210 | 211 | ``` 212 | 最终用户通过继承`AbstractCalculator`类，并在`Component`注解中指定一个值，而`CalculatorRouter`则通过这个值将请求路由到相应的优惠计算器，这个值与`DiscountWrapper`中的`type`属性相对应。 213 | 214 | ```Java 215 | @Component("manjian") 216 | public class ManjianCalc extends AbstractCalculator { 217 | ...... 218 | } 219 | ``` 220 | 221 | 222 | #### 共享互斥协议 DiscountGroup 223 | 224 | 共享互斥协议是一个数据结构，它是一个数组，数组中最多可以包含两个对象，最少包含一个对象。如果数组中只有一个对象，那么该对象必然为共享组，即组内的优惠可以叠加使用。 225 | 226 | ```JavaScript 227 | [ 228 | { 229 | "relation": "share", 230 | "items": 231 | [ 232 | { 233 | "type": "activity0", 234 | "id": "11" 235 | } 236 | , 237 | { 238 | "type": "activity4", 239 | "id": "13" 240 | } 241 | , 242 | { 243 | "type": "coupon1", 244 | "id": "14" 245 | } 246 | ] 247 | }] 248 | ``` 249 | 相应的，当数组中包含两个对象时，第一个对象的`relation`属性可以为`share`或`exclude`，而第二个对象的`relation`属性必须为`exclude`。 250 | 251 | ```JavaScript 252 | [ 253 | { 254 | "relation": "share", 255 | "items": 256 | [ 257 | { 258 | "type": "activity0", 259 | "id": "11" 260 | }, 261 | { 262 | "type": "card3", 263 | "id":"12" 264 | } 265 | ] 266 | }, 267 | { 268 | "relation": "exclude", 269 | "items": 270 | [ 271 | { 272 | "type": "card1", 273 | "id": "18" 274 | }, 275 | { 276 | "type": "coupon1", 277 | "id": "22" 278 | } 279 | ] 280 | } 281 | ] 282 | ``` 283 | 最终，上述协议将转化为如下两个共享组： 284 | 285 | - `activity0-card3-card1` 和 `activity0-card3-coupon1` 286 | 287 | 工具类 `DiscountGroupUtil` 提供了一个方法，用于将协议转换为共享组。由于共享组可能包含大量优惠，为了提高过滤性能，我们将当前可用的优惠转换为二级`Map`。这个`Map`的外层键是协议中的`type`，而第二层键是协议中的`id`。通过这种方式，我们可以快速地进行交叉过滤，从而提升性能。 288 | 289 | ```Java 290 | public static List,Set>> transform(List> groups, Map> inMap); 291 | ``` 292 | 为了确保计算性能，我们将用户在当前订单中可享受的优惠分为两个集合。左侧集合的大小限制为`SUPPORTEDSIZE`，即我们重点保障的、在计算能力范围内的优惠。而右侧集合则尽可能地进行叠加。 293 | 294 | 从稳定性角度考虑，我们需要对计算次数进行统计。在压力测试中，我们通过`LimitingUtil.count`方法来统计进入`calc`方法的次数。显然，在没有开启缓存的情况下，计算次数为 $A_n^n$×n，而当开启缓存时，计算次数为 $A_n^n$×(n−3)+ $A_n^3$。 295 | 296 | #### CASE 297 | 298 | 看了这么多概念，我们可以在`com.gch.discount.demo`包中找到实际调用的具体case： 299 | 300 | ```Java 301 | @Controller 302 | public class TestController { 303 | 304 | private final CalculatorRouter calculatorRouter; 305 | 306 | public TestController(CalculatorRouter calculatorRouter) { 307 | this.calculatorRouter = calculatorRouter; 308 | } 309 | 310 | @RequestMapping("test") 311 | @ResponseBody 312 | public Object test() { 313 | //mock商品 314 | List items = mockItems(); 315 | //mock组关系并转化为共享组 316 | List,Set>> pairs = transform(mockGroups()); 317 | //全局最优计算过程 318 | List globalStages=Lists.newArrayList(); 319 | int count = 0; 320 | //订单总金额 321 | long totalPrice = items.stream().mapToLong(GoodsInfo::getSalePrice).sum(); 322 | long globalPrice = totalPrice; 323 | //构建计算流 324 | Flowable flowable = (Flowable) new Flowable().build(calculatorRouter); 325 | for(Pair,Set> set:pairs) { 326 | //统计算力 327 | count += LimitingUtil.count(set.getLeft().size()); 328 | if(count>N){ 329 | break; 330 | } 331 | List wrappers = Lists.newArrayList(set.getLeft()); 332 | DiscountContext ctx = DiscountContext.create(totalPrice, Lists.newArrayList(items), wrappers); 333 | flowable.perm(ctx); 334 | if(ctx.getCalcResult().getFinalPrice() < globalPrice) { 335 | globalStages = Arrays.asList(ctx.getCalcResult().getStages()); 336 | globalPrice = ctx.getCalcResult().getFinalPrice(); 337 | } 338 | } 339 | return Pair.of(globalPrice,globalStages); 340 | } 341 | 342 | private List> mockGroups(){ 343 | List> groups = Lists.newArrayList(); 344 | DiscountGroup group = new DiscountGroup(); 345 | group.setRelation(GroupRelation.SHARE.getType()); 346 | group.setItems(Lists.newArrayList(new Item("zhekou","1"),new Item("manjian","2"),new Item("manzeng","3"))); 347 | groups.add(Lists.newArrayList(group)); 348 | return groups; 349 | } 350 | 351 | private List mockItems(){ 352 | IdGenerator idGenerator = IdGenerator.getInstance(); 353 | GoodsInfo goodsInfo = GoodsInfo.of(1001L,2001L,null,4,20 * 100,"产品1",null); 354 | GoodsInfo goodsInfo2 = GoodsInfo.of(1001L,2002L,null,2,10 * 100,"产品1",null); 355 | List items = GoodsItem.generateItems(goodsInfo,idGenerator,x->x.getExtra().put(Constant.UPDATEABLEPRICE,x.getSalePrice())); 356 | items.addAll(GoodsItem.generateItems(goodsInfo2,idGenerator,x->x.getExtra().put(Constant.UPDATEABLEPRICE,x.getSalePrice()))); 357 | return items; 358 | } 359 | 360 | private List,Set>> transform(List> groups){ 361 | List wrapperList = Lists.newArrayList( 362 | DiscountWrapper.of("zhekou", "1", "折扣", false, new DiscountConfig()), 363 | DiscountWrapper.of("manjian", "2", "满减", false, new DiscountConfig()) 364 | ); 365 | Map> inMap = wrapperList.stream().collect(Collectors.toMap(DiscountWrapper::getType, x->ImmutableMap.of(x.getId(),x))); 366 | return DiscountGroupUtil.transform(groups,inMap); 367 | } 368 | } 369 | 370 | ``` 371 | 372 | 373 | 374 | 375 | 376 | -------------------------------------------------------------------------------- /READMEIMG/211690962797_.pic.jpg: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/GaoSSR/OnePRO/c7aac1eb3ea695cba74b4bc0cfc6d19feca93a6f/READMEIMG/211690962797_.pic.jpg -------------------------------------------------------------------------------- /READMEIMG/Project-Name.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/GaoSSR/OnePRO/c7aac1eb3ea695cba74b4bc0cfc6d19feca93a6f/READMEIMG/Project-Name.png -------------------------------------------------------------------------------- /READMEIMG/image（1）.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/GaoSSR/OnePRO/c7aac1eb3ea695cba74b4bc0cfc6d19feca93a6f/READMEIMG/image（1）.png -------------------------------------------------------------------------------- /READMEIMG/image（2）.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/GaoSSR/OnePRO/c7aac1eb3ea695cba74b4bc0cfc6d19feca93a6f/READMEIMG/image（2）.png -------------------------------------------------------------------------------- /pom.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 5 | 6 | com.gch 7 | 4.0.0 8 | jar 9 | OnePRO 10 | OnePRO 11 | 1.0-SNAPSHOT 12 | 13 | 14 | org.springframework.boot 15 | spring-boot-starter-parent 16 | 2.2.6.RELEASE 17 | 18 | 19 | 20 | 21 | UTF-8 22 | 1.8 23 | 1.8 24 | 25 | 26 | 27 | 28 | org.reflections 29 | reflections 30 | 0.10.2 31 | 32 | 33 | org.apache.commons 34 | commons-lang3 35 | 3.12.0 36 | 37 | 38 | com.alibaba 39 | fastjson 40 | 1.2.80 41 | 42 | 43 | org.apache.commons 44 | commons-collections4 45 | 4.4 46 | 47 | 48 | com.google.guava 49 | guava 50 | 31.1-jre 51 | 52 | 53 | org.projectlombok 54 | lombok 55 | 1.18.24 56 | 57 | 58 | org.springframework.boot 59 | spring-boot-starter-web 60 | 2.2.6.RELEASE 61 | 62 | 63 | org.springframework.boot 64 | spring-boot-starter-test 65 | 2.2.6.RELEASE 66 | 67 | 68 | net.logstash.logback 69 | logstash-logback-encoder 70 | 4.9 71 | 72 | 73 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/aware/CalculatorRouter.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.aware; 18 | 19 | import com.gch.discount.core.discount.Calculator; 20 | import org.springframework.beans.BeansException; 21 | import org.springframework.context.ApplicationContext; 22 | import org.springframework.context.ApplicationContextAware; 23 | import org.springframework.stereotype.Component; 24 | 25 | import java.util.Map; 26 | 27 | /** 28 | * 根据注解路由到目标Calculator 29 | * @author: GaoSSR 30 | * @date: 2023/8 31 | */ 32 | @Component 33 | @SuppressWarnings("all") 34 | public class CalculatorRouter implements ApplicationContextAware { 35 | 36 | private Map map; 37 | 38 | @Override 39 | public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { 40 | map = applicationContext.getBeansOfType(Calculator.class); 41 | } 42 | 43 | 44 | public Map getMap() { 45 | return map; 46 | } 47 | 48 | public Calculator getService(String key) { 49 | return map.get(key); 50 | } 51 | 52 | } 53 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/discount/Calculator.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.discount; 18 | 19 | import com.gch.discount.core.model.common.DiscountContext; 20 | import com.gch.discount.core.model.common.DiscountWrapper; 21 | import com.gch.discount.core.model.goods.GoodsItem; 22 | 23 | import java.util.Map; 24 | 25 | /** 26 | * 优惠计算器接口 27 | * @author: GaoSSR 28 | * @date: 2023/8 29 | */ 30 | public interface Calculator { 31 | 32 | /** 33 | * 优惠计算引擎的内部方法 34 | * @param context 上下文 35 | * @param discountWrapper 当前优惠信息 36 | * @param records 参与优惠的商品记录，用于过滤 37 | * @param idx 活动的index 38 | * @param i 当前计算的索引下标，它和idx的区别在于比如有数组[9,4,6,5],则i为数组下标 i=1 时对应的idx是4 39 | */ 40 | long calcWarp(DiscountContext context, DiscountWrapper discountWrapper, Map records, byte idx, int i); 41 | } 42 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/discount/impl/AbstractCalculator.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.discount.impl; 18 | 19 | import com.gch.discount.core.discount.Calculator; 20 | import com.gch.discount.core.model.common.*; 21 | import com.gch.discount.core.model.goods.GoodsItem; 22 | 23 | import java.util.Map; 24 | 25 | /** 26 | * 抽象计算器类，每种类型优惠做一个实现类，负责创建 stage，维护CalcStage[]数组等内部工作，这对使用者是透明的 27 | * @author: GaoSSR 28 | * @date: 2023/8 29 | */ 30 | public abstract class AbstractCalculator implements Calculator { 31 | 32 | public long calcWarp(DiscountContext context, DiscountWrapper discountWrapper, Map records, byte idx, int i) { 33 | CalcStage stage = new CalcStage(); 34 | CalcResult cr = context.getCalcResult(); 35 | long price = cr.getCurPrice(); 36 | stage.setBeforeCalcPrice(price); 37 | price = calc(context, discountWrapper, records, price, stage); 38 | if (price < 0) { 39 | return price; 40 | } 41 | stage.setAfterCalcPrice(price); 42 | stage.setIndex(idx); 43 | stage.setStageType(discountWrapper.getType()); 44 | cr.setCurPrice(price); 45 | if (stage.getBeforeCalcPrice() > stage.getAfterCalcPrice()) { 46 | cr.getCurStages()[i] = stage; 47 | } 48 | return price; 49 | } 50 | 51 | /** 52 | * 返回该优惠下的最终要支付的金额,若不符合则返回 prevStagePrice 53 | * @param context 上下文 54 | * @param discountWrapper 优惠信息 55 | * @param records 记录享受过优惠的单品，key是calculateId，这里只提供容器，添加和判断规则由使用者自行决定 56 | * @param prevStagePrice 上一步计算出的订单的价格 57 | * @param curStage 当前stage 58 | * @return 59 | */ 60 | public abstract long calc(DiscountContext context, DiscountWrapper discountWrapper, Map records, long prevStagePrice, CalcStage curStage); 61 | 62 | } 63 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/enums/GroupRelation.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.enums; 18 | 19 | /** 20 | * 组内关系枚举 21 | * 组内关系枚举 22 | * @author: GaoSSR 23 | * @date: 2023/8 24 | */ 25 | public enum GroupRelation { 26 | 27 | SHARE("share"), 28 | EXCLUDE("exclude"); 29 | 30 | private String type; 31 | 32 | GroupRelation(String type) { 33 | this.type = type; 34 | } 35 | 36 | public String getType() { 37 | return type; 38 | } 39 | 40 | public void setType(String type) { 41 | this.type = type; 42 | } 43 | } 44 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/CalcResult.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import com.fasterxml.jackson.annotation.JsonIgnore; 20 | import lombok.Data; 21 | 22 | import java.io.Serializable; 23 | 24 | /** 25 | * 优惠计算结果 26 | * @author: GaoSSR 27 | * @date: 2023/8 28 | */ 29 | @Data 30 | public class CalcResult implements Serializable { 31 | 32 | private CalcResult() { 33 | } 34 | 35 | /** 36 | * 最优实付金额 37 | */ 38 | private long finalPrice; 39 | 40 | /** 41 | * 最优优惠计算过程 42 | */ 43 | private CalcStage[] stages; 44 | 45 | /** 46 | * 当前序列计算的实付金额 47 | */ 48 | @JsonIgnore 49 | private transient long curFinalPrice; 50 | 51 | /** 52 | * 当前序列优惠计算过程 53 | */ 54 | @JsonIgnore 55 | private transient CalcStage[] curStages; 56 | 57 | /** 58 | * 实时计算价格 59 | */ 60 | @JsonIgnore 61 | private transient long curPrice; 62 | 63 | public static CalcResult create(int n) { 64 | CalcResult c = new CalcResult(); 65 | c.stages = new CalcStage[n]; 66 | c.curStages = new CalcStage[n]; 67 | return c; 68 | } 69 | 70 | } 71 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/CalcStage.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import lombok.*; 20 | 21 | import java.io.Serializable; 22 | import java.util.Map; 23 | 24 | /** 25 | * 单个具体优惠计算明细，可以当成日志来用，用于计算过程的追溯 26 | * @author: GaoSSR 27 | * @date: 2023/8 28 | */ 29 | @Data 30 | public class CalcStage implements Serializable { 31 | 32 | /** 33 | * 优惠前价格 34 | */ 35 | private long beforeCalcPrice; 36 | 37 | /** 38 | * 优惠后价格 39 | */ 40 | private long afterCalcPrice; 41 | 42 | /** 43 | * 优惠类型 44 | */ 45 | private String stageType; 46 | 47 | /** 48 | * 优惠索引 49 | */ 50 | private byte index; 51 | 52 | /** 53 | * 扩展属性 54 | */ 55 | private Map extra; 56 | 57 | } 58 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/CalcState.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import com.gch.discount.core.model.goods.GoodsItem; 20 | import lombok.Data; 21 | 22 | import java.io.Serializable; 23 | import java.util.Map; 24 | 25 | /** 26 | * 保存点，用于缓存，入计算到第3个节点时可以将所有状态写入CalcState 27 | * @author: GaoSSR 28 | * @date: 2023/8 29 | */ 30 | @Data 31 | public class CalcState implements Serializable { 32 | 33 | /** 34 | * 截止到保存点计算的最终优惠价格 35 | */ 36 | private long curPrice; 37 | 38 | /** 39 | * 截止到保存点计算的CalcStage 40 | */ 41 | private CalcStage[] curStages; 42 | 43 | /** 44 | * 截止到保存点的商品列表 45 | */ 46 | private Map goodsItems; 47 | 48 | /** 49 | * 截止到保存点的已计算商品列表 50 | */ 51 | private Map records; 52 | 53 | /** 54 | * 截止到保存点的扩展信息 55 | */ 56 | private Map extra; 57 | } 58 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/DiscountConfig.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import lombok.Data; 20 | 21 | import java.io.Serializable; 22 | import java.util.List; 23 | import java.util.Map; 24 | 25 | /** 26 | * 优惠配置信息 27 | * @author: GaoSSR 28 | * @date: 2023/7 29 | */ 30 | @Data 31 | public class DiscountConfig implements Serializable { 32 | 33 | /** 34 | * 当前优惠的优先级（如10 - 单商品组， 20 - 整单组） 35 | */ 36 | private int calculateGroup; 37 | 38 | /** 39 | * 商品限制 (0 - 所有商品可参与，1 - 指定某些商品参与， 2- 指定某些商品不参与) 40 | */ 41 | private int goodsType; 42 | 43 | /** 44 | * 下一个属性 itemIds 存放的内容是啥，（0 - 商品ID， 1 - SKUID， 2 - 类目Id） 45 | */ 46 | private int itemIdType; 47 | 48 | /** 49 | * 同上 50 | */ 51 | private List itemIds; 52 | 53 | /** 54 | * 活动信息扩展信息 55 | */ 56 | private Map extra; 57 | 58 | } 59 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/DiscountContext.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import com.gch.discount.core.model.goods.GoodsItem; 20 | import com.gch.discount.core.precompute.PreCompute; 21 | import com.gch.discount.core.precompute.PreComputeHolder; 22 | import com.google.common.collect.Lists; 23 | import com.google.common.collect.Maps; 24 | import lombok.Data; 25 | import org.apache.commons.collections4.CollectionUtils; 26 | 27 | import java.io.Serializable; 28 | import java.util.List; 29 | import java.util.Map; 30 | import java.util.stream.Collectors; 31 | 32 | /** 33 | * 优惠上下文，包含一些初始化工作、预计算等等 34 | * @author: GaoSSR 35 | * @date: 2023/8 36 | */ 37 | @Data 38 | public class DiscountContext implements Serializable { 39 | 40 | private DiscountContext() { 41 | } 42 | 43 | /** 44 | * 原始价格 45 | */ 46 | private long originalPrice; 47 | 48 | /** 49 | * 优惠的计算结果 50 | */ 51 | private CalcResult calcResult; 52 | 53 | 54 | /** 55 | * 当前订单参与计算的商品 56 | */ 57 | private List goodsItems; 58 | 59 | /** 60 | * 当前订单可用优惠的配置 61 | */ 62 | private List discountWrappers; 63 | 64 | /** 65 | * 优惠维度进行商品分组，这样每个计算器只取自己相关的商品 66 | */ 67 | private Map> discountItemGroup; 68 | 69 | /** 70 | * 记录享受过优惠的单品，key是calculateId 71 | */ 72 | private Map records; 73 | 74 | /** 75 | * 存储预计算的结果 76 | */ 77 | private Map preCompute; 78 | 79 | /** 80 | * 扩展字段 81 | */ 82 | private Map extra; 83 | 84 | 85 | /** 86 | * 构造一个上下文 87 | * 88 | * @param originalPrice 订单原始价格 89 | * @param goodsItems 可用商品列表 90 | * @param discountWrappers 可用优惠列表 91 | * @return 92 | */ 93 | public static DiscountContext create(long originalPrice, List goodsItems, List discountWrappers) { 94 | DiscountContext c = new DiscountContext<>(); 95 | c.originalPrice = originalPrice; 96 | c.records = Maps.newHashMap(); 97 | c.discountItemGroup = Maps.newHashMap(); 98 | c.calcResult = CalcResult.create(discountWrappers.size()); 99 | c.calcResult.setFinalPrice(originalPrice); 100 | c.goodsItems = goodsItems; 101 | c.discountWrappers = discountWrappers; 102 | c.preCompute = Maps.newHashMap(); 103 | //预处理优惠 104 | for (DiscountWrapper discount : discountWrappers) { 105 | initDiscount(c, discount); 106 | } 107 | return c; 108 | } 109 | 110 | 111 | /** 112 | * 对某个优惠进行初始化工作，包括商品的筛选、预计算逻辑 113 | * 114 | * @param c 上下文 115 | * @param discount 当前优惠的信息 116 | */ 117 | private static void initDiscount(DiscountContext c, DiscountWrapper discount) { 118 | DiscountConfig conf = discount.getDiscountConfig(); 119 | List list = Lists.newArrayList(c.goodsItems); 120 | if (0 == conf.getGoodsType()) { 121 | //不限制 122 | list = list.stream().sorted().collect(Collectors.toList()); 123 | c.discountItemGroup.put(discount.getId(), list); 124 | } else if (1 == conf.getGoodsType()) { 125 | if (0 == conf.getItemIdType()) { 126 | list = list.stream().filter(x -> conf.getItemIds(). 127 | contains(x.getGoodsId())).sorted().collect(Collectors.toList()); 128 | c.discountItemGroup.put(discount.getId(), list); 129 | } else if (1 == conf.getItemIdType()) { 130 | list = list.stream().filter(x -> conf.getItemIds(). 131 | contains(x.getSkuId())).sorted().collect(Collectors.toList()); 132 | c.discountItemGroup.put(discount.getId(), list); 133 | } else { 134 | list = list.stream().filter(x -> CollectionUtils.intersection( 135 | conf.getItemIds(), x.getCategoryIds()).size() > 0).sorted().collect(Collectors.toList()); 136 | c.discountItemGroup.put(discount.getId(), list); 137 | } 138 | } else { 139 | //指定不参与 140 | if (0 == conf.getItemIdType()) { 141 | list = list.stream().filter(x -> !conf.getItemIds(). 142 | contains(x.getGoodsId())).sorted().collect(Collectors.toList()); 143 | c.discountItemGroup.put(discount.getId(), list); 144 | } else if (1 == conf.getItemIdType()) { 145 | list = list.stream().filter(x -> !conf.getItemIds(). 146 | contains(x.getSkuId())).sorted().collect(Collectors.toList()); 147 | c.discountItemGroup.put(discount.getId(), list); 148 | } else { 149 | list = list.stream().filter(x -> CollectionUtils.intersection( 150 | conf.getItemIds(), x.getCategoryIds()).size() == 0).sorted().collect(Collectors.toList()); 151 | c.discountItemGroup.put(discount.getId(), list); 152 | } 153 | } 154 | runPreCompute(c, discount, list); 155 | } 156 | 157 | /** 158 | * 预计算 159 | * 160 | * @param c 上下文 161 | * @param discount 当前的优惠信息 162 | * @param list 当前优惠匹配的商品列表 163 | */ 164 | @SuppressWarnings("unchecked") 165 | private static void runPreCompute(DiscountContext c, DiscountWrapper discount, List list) { 166 | list = Lists.newArrayList(list); 167 | for (PreCompute e : PreComputeHolder.COMPUTES) { 168 | if (e.matchTypes().contains(discount.getType())) { 169 | e.preComputeItems(list, discount, c.preCompute); 170 | } 171 | } 172 | } 173 | 174 | } 175 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/DiscountGroup.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import com.google.common.collect.Lists; 20 | import lombok.*; 21 | import org.apache.commons.collections4.CollectionUtils; 22 | import org.apache.commons.collections4.MapUtils; 23 | import org.apache.commons.lang3.StringUtils; 24 | 25 | import java.io.Serializable; 26 | import java.util.Iterator; 27 | import java.util.List; 28 | import java.util.Map; 29 | 30 | /** 31 | * 共享互斥组 32 | * @author: GaoSSR 33 | * @date: 2023/8 34 | */ 35 | @Data 36 | public class DiscountGroup implements Serializable { 37 | 38 | private String relation; 39 | private List items; 40 | 41 | /** 42 | * 根据用户可用的优惠，对组内信息进行过滤 43 | * @param inMap 44 | * @return 45 | */ 46 | public List filterItems(Map> inMap) { 47 | //inMap 外层key为type，内层key为id，value为DiscountWrapper 48 | if (CollectionUtils.isEmpty(items) || MapUtils.isEmpty(inMap)) { 49 | return null; 50 | } 51 | //构建items副本 52 | List itemsCopy = Lists.newArrayList(items); 53 | Iterator it = itemsCopy.iterator(); 54 | while (it.hasNext()) { 55 | Item item = it.next(); 56 | if (!inMap.containsKey(item.getType())) { 57 | it.remove(); 58 | continue; 59 | } 60 | if (StringUtils.isNotBlank(item.getId())) { 61 | //理论上m不可能为空 62 | Map m = inMap.get(item.getType()); 63 | if (MapUtils.isNotEmpty(m)) { 64 | if (!m.containsKey(item.getId())) { 65 | it.remove(); 66 | } 67 | } 68 | } 69 | } 70 | return itemsCopy; 71 | } 72 | } 73 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/DiscountWrapper.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import lombok.Data; 20 | 21 | import java.io.Serializable; 22 | import java.util.Objects; 23 | 24 | /** 25 | * 优惠类 26 | * @author: GaoSSR 27 | * @date: 2023/7 28 | */ 29 | @Data 30 | public class DiscountWrapper implements Serializable, Comparable { 31 | 32 | /** 33 | * 优惠的具体类型，CalculatorRouter会根据这个type在Calculator的实现类中扫描 34 | */ 35 | private String type; 36 | 37 | /** 38 | * 优惠的ID 39 | */ 40 | private String id; 41 | 42 | /** 43 | * 优惠的名称 44 | */ 45 | private String name; 46 | 47 | /** 48 | * 是否是必须使用的优惠 49 | */ 50 | private boolean mustUse; 51 | 52 | /** 53 | * 优惠的配置信息 54 | */ 55 | private DiscountConfig discountConfig; 56 | 57 | 58 | public static DiscountWrapper of(String type, String id, String name, boolean mustUse, DiscountConfig discountConfig) { 59 | DiscountWrapper wrapper = new DiscountWrapper(); 60 | wrapper.setType(type); 61 | wrapper.setId(id); 62 | wrapper.setName(name); 63 | wrapper.setMustUse(mustUse); 64 | wrapper.setDiscountConfig(discountConfig); 65 | return wrapper; 66 | } 67 | 68 | @Override 69 | public boolean equals(Object o) { 70 | if (this == o) return true; 71 | if (o == null || getClass() != o.getClass()) return false; 72 | DiscountWrapper wrapper = (DiscountWrapper) o; 73 | return type.equals(wrapper.type) && id.equals(wrapper.id); 74 | } 75 | 76 | @Override 77 | public int hashCode() { 78 | return Objects.hash(type, id); 79 | } 80 | 81 | @Override 82 | public int compareTo(DiscountWrapper o) { 83 | return (this.type + this.id).compareTo(o.getType() + o.getId()); 84 | } 85 | 86 | } 87 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/common/Item.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.common; 18 | 19 | import lombok.*; 20 | 21 | import java.io.Serializable; 22 | 23 | /** 24 | * 共享互斥关系中的元素 25 | * @author: GaoSSR 26 | * @date: 2023/8 27 | */ 28 | @AllArgsConstructor 29 | @NoArgsConstructor 30 | @Getter 31 | @Setter 32 | @ToString 33 | @EqualsAndHashCode 34 | public class Item implements Serializable { 35 | /** 36 | * 优惠类型，和DiscountWrapper中的type保持一致 37 | */ 38 | private String type; 39 | 40 | /** 41 | * 优惠的ID，和DiscountWrapper中的id保持一致 42 | */ 43 | private String id; 44 | } 45 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/goods/GoodsInfo.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.goods; 18 | 19 | import com.google.common.collect.Maps; 20 | import lombok.Data; 21 | 22 | import java.io.Serializable; 23 | import java.util.List; 24 | import java.util.Map; 25 | 26 | /** 27 | * 商品信息 28 | * @author: GaoSSR 29 | * @date: 2023/7 30 | */ 31 | @Data 32 | public class GoodsInfo implements Serializable, Cloneable { 33 | 34 | /** 35 | * 商品ID 36 | */ 37 | private Long goodsId; 38 | 39 | /** 40 | * 商品的SKUID 41 | */ 42 | private Long skuId; 43 | 44 | /** 45 | * 商品分类ID,一个商品可能出现在多个品类中 46 | */ 47 | private List categoryIds; 48 | 49 | /** 50 | * 购买数量 51 | */ 52 | private int num; 53 | 54 | /** 55 | * 商品价格，用于计算（单位：分） 56 | */ 57 | private long salePrice; 58 | 59 | /** 60 | * 商品名 61 | */ 62 | private String name; 63 | 64 | /** 65 | * 商品扩展属性 66 | */ 67 | private Map goodsExtra = Maps.newHashMap(); 68 | 69 | 70 | public static GoodsInfo of(Long goodsId, Long skuId, List categoryIds, int num, long salePrice, String name, Map goodsExtra) { 71 | GoodsInfo goodsInfo = new GoodsInfo(); 72 | goodsInfo.setGoodsId(goodsId); 73 | goodsInfo.setCategoryIds(categoryIds); 74 | goodsInfo.setNum(num); 75 | goodsInfo.setSkuId(skuId); 76 | goodsInfo.setSalePrice(salePrice); 77 | goodsInfo.setName(name); 78 | goodsInfo.setGoodsExtra(goodsExtra); 79 | return goodsInfo; 80 | } 81 | 82 | @Override 83 | public GoodsInfo clone() throws CloneNotSupportedException { 84 | return (GoodsInfo) super.clone(); 85 | } 86 | } 87 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/model/goods/GoodsItem.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.model.goods; 18 | 19 | import com.gch.discount.core.utils.IdGenerator; 20 | import com.google.common.collect.Lists; 21 | import com.google.common.collect.Maps; 22 | import lombok.*; 23 | 24 | import java.io.Serializable; 25 | import java.util.List; 26 | import java.util.Map; 27 | import java.util.Objects; 28 | import java.util.function.Consumer; 29 | 30 | /** 31 | * 拆分后的商品，比如一个商品GoodsInfo买了2件则会产出2个GoodsItem 32 | * @author: GaoSSR 33 | * @date: 2023/7 34 | */ 35 | @Data 36 | public class GoodsItem extends GoodsInfo implements Serializable, Comparable, Cloneable { 37 | 38 | /** 39 | * 根据基本信息构造具体的计算商品，复制属性，以及单商品唯一id 40 | * @param calculateId 41 | * @param goodsInfo 42 | */ 43 | public GoodsItem(long calculateId, GoodsInfo goodsInfo) { 44 | this.calculateId = calculateId; 45 | this.setGoodsId(goodsInfo.getGoodsId()); 46 | this.setCategoryIds(goodsInfo.getCategoryIds()); 47 | this.setName(goodsInfo.getName()); 48 | this.setSkuId(goodsInfo.getSkuId()); 49 | this.setSalePrice(goodsInfo.getSalePrice()); 50 | } 51 | 52 | /** 53 | * 引擎计算时使用的id，每个单独商品一个 54 | */ 55 | private Long calculateId; 56 | 57 | /** 58 | * 商品扩展属性 59 | */ 60 | private Map extra = Maps.newHashMap(); 61 | 62 | /** 63 | * 根据商品信息（数量），生成计算时候需要的具体商品（单个） 64 | * 65 | * @param goodsInfo 商品信息 66 | * @param idGenerator id生成器 67 | * @param consumer 在创建商品的同时对extra中的内容进行初始化 68 | */ 69 | @SuppressWarnings("unchecked") 70 | public static List generateItems(GoodsInfo goodsInfo, IdGenerator idGenerator, Consumer consumer) { 71 | if (Objects.isNull(goodsInfo)) { 72 | return Lists.newArrayList(); 73 | } 74 | List goodsItems = Lists.newArrayList(); 75 | for (int i = 0; i < goodsInfo.getNum(); i++) { 76 | T item = (T) new GoodsItem(idGenerator.nextId(), goodsInfo); 77 | consumer.accept(item); 78 | goodsItems.add(item); 79 | } 80 | return goodsItems; 81 | } 82 | 83 | @Override 84 | public boolean equals(Object o) { 85 | if (this == o) { 86 | return true; 87 | } 88 | if (o == null || getClass() != o.getClass()) { 89 | return false; 90 | } 91 | GoodsItem goodsItem = (GoodsItem) o; 92 | return Objects.equals(calculateId, goodsItem.calculateId); 93 | } 94 | 95 | @Override 96 | public int hashCode() { 97 | return Objects.hash(calculateId); 98 | } 99 | 100 | @Override 101 | public int compareTo(GoodsItem o) { 102 | return this.getCalculateId().compareTo(o.getCalculateId()); 103 | } 104 | 105 | @Override 106 | public GoodsItem clone() throws CloneNotSupportedException { 107 | return (GoodsItem) super.clone(); 108 | } 109 | 110 | } 111 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/permutation/Permutation.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.permutation; 18 | 19 | import com.gch.discount.core.aware.CalculatorRouter; 20 | import com.gch.discount.core.discount.Calculator; 21 | import com.gch.discount.core.model.common.*; 22 | import com.gch.discount.core.model.goods.GoodsItem; 23 | import com.google.common.collect.Collections2; 24 | import com.google.common.collect.Maps; 25 | import com.google.common.collect.Sets; 26 | import org.apache.commons.collections4.CollectionUtils; 27 | 28 | import java.util.*; 29 | import java.util.stream.Collectors; 30 | import java.util.stream.IntStream; 31 | 32 | 33 | /** 34 | * 全排列计算引擎 35 | * @author: GaoSSR 36 | * @date: 2023/8 37 | */ 38 | 39 | @SuppressWarnings("all") 40 | public abstract class Permutation { 41 | 42 | /** 43 | * 根据注解路由到目标Calculator 44 | */ 45 | private CalculatorRouter calculatorRouter; 46 | 47 | /** 48 | * 上下文 49 | */ 50 | private DiscountContext context; 51 | 52 | /** 53 | * 必须使用的优惠，比如用户手动选择的优惠 54 | */ 55 | private final Set mustUseSet = Sets.newHashSet(); 56 | 57 | /** 58 | * 缓存，key是calcKey生成的数字，value是保存点 59 | */ 60 | private final Map> cache = Maps.newHashMap(); 61 | 62 | /** 63 | * 将calculatorRouter绑定到当前Permutation 64 | * @param calculatorRouter 路由器 65 | * @return 66 | */ 67 | public Permutation build(CalculatorRouter calculatorRouter) { 68 | this.calculatorRouter = calculatorRouter; 69 | return this; 70 | } 71 | 72 | /** 73 | * 1-SUPPORTEDSIZE 之间所有排列组合的记录 74 | */ 75 | private final static Map>> PERMUTATIONS = Maps.newHashMap(); 76 | 77 | /** 78 | * 最大支持的共享组长度 79 | */ 80 | public final static int SUPPORTEDSIZE = 7; 81 | 82 | static { 83 | //前置计算 1-SUPPORTEDSIZE 之间所有排列组合 84 | for (byte i = 1; i <= SUPPORTEDSIZE; i++) { 85 | PERMUTATIONS.put((int) i, Collections2.permutations(IntStream.range(0, i).boxed() 86 | .map(x -> (byte) x.intValue()).collect(Collectors.toList()))); 87 | } 88 | } 89 | 90 | /** 91 | * 计算用户选择的优惠组合是否有可行解 92 | * @param context 上下文 93 | * @return 94 | */ 95 | public boolean findSolution(DiscountContext context) { 96 | int size = context.getDiscountWrappers().size(); 97 | this.context = context; 98 | if (size == 0) { 99 | return false; 100 | } 101 | Collection> list = PERMUTATIONS.get(size); 102 | for (List a : list) { 103 | if (findSolution(context, a)) { 104 | return true; 105 | } 106 | } 107 | cache.clear(); 108 | mustUseSet.clear(); 109 | return false; 110 | } 111 | 112 | /** 113 | * 计算最优解 114 | * @param context 上下文 115 | * @return 116 | */ 117 | public void perm(DiscountContext context) { 118 | int size = context.getDiscountWrappers().size(); 119 | this.context = context; 120 | loadMustUseDiscount(); 121 | if (size == 0) { 122 | return; 123 | } 124 | Collection> list = PERMUTATIONS.get(size); 125 | for (List a : list) { 126 | boolean isBetter = executeCalc(this.context, a); 127 | if (isBetter) { 128 | //若出现比当前结果更优的结果则替换 129 | updateRecord(this.context.getCalcResult()); 130 | } 131 | } 132 | cache.clear(); 133 | mustUseSet.clear(); 134 | } 135 | 136 | private void loadMustUseDiscount() { 137 | for (int i = 0; i < context.getDiscountWrappers().size(); i++) { 138 | if (context.getDiscountWrappers().get(i).isMustUse()) { 139 | this.mustUseSet.add((byte) i); 140 | } 141 | } 142 | } 143 | 144 | /** 145 | * 根据byte数组生成唯一数字作为Map的key，避免字符串拼接等低效操作 146 | */ 147 | private static Integer calcKey(List a) { 148 | return a.size() >= 3 ? (a.get(0) << 6) + (a.get(1) << 3) + a.get(2) : 0; 149 | } 150 | 151 | /** 152 | * 若出现比当前结果更优的结果则替换 153 | * @param result 当前的计算结果 154 | */ 155 | private void updateRecord(CalcResult result) { 156 | result.setFinalPrice(result.getCurFinalPrice()); 157 | System.arraycopy(result.getCurStages(), 0, result.getStages(), 0, result.getStages().length); 158 | } 159 | 160 | /** 161 | * 找到可行解，这种情况list中所有优惠必须被使用 162 | * @param context 上下文 163 | * @param a 当前计算的排列 164 | */ 165 | private boolean findSolution(DiscountContext context, List a) { 166 | Integer k = calcKey(a); 167 | boolean canOptimize = enableOptimize(a) && cache.containsKey(k); 168 | initInner(canOptimize, k); 169 | for (int i = canOptimize ? 3 : 0; i < a.size(); i++) { 170 | DiscountWrapper wrapper = context.getDiscountWrappers().get(a.get(i)); 171 | Calculator calculator = (Calculator) calculatorRouter.getService(wrapper.getType()); 172 | //路由目标的计算器实现 173 | if (canOptimize && checkIfWakeUpJump(context.getDiscountWrappers().get(a.get(2)), wrapper)) { 174 | //还原保存点后，比较保存点的最后一个优惠节点和当前优惠的优先级，如不符合则跳出 175 | break; 176 | } 177 | if (Objects.nonNull(calculator)) { 178 | //执行计算器 179 | if (!calcInner(calculator, wrapper, a, i)) { 180 | return false; 181 | } 182 | CalcStage cs = context.getCalcResult().getCurStages()[i]; 183 | if (Objects.isNull(cs)) { 184 | //执行当前排列，若存在未使用的优惠则证明当前排列不可行 185 | return false; 186 | } 187 | //优惠长度为5、6、7 将开启优化，只缓存走到第3个节点的部分 188 | cacheSnapshot(a, i, k); 189 | } 190 | } 191 | return true; 192 | } 193 | 194 | private void cacheSnapshot(List a, int i, Integer k) { 195 | if (enableOptimize(a) && i == 2 && !cache.containsKey(k)) { 196 | cache.put(k, makeSnapshot(context.getGoodsItems())); 197 | } 198 | } 199 | 200 | private void initInner(boolean canOptimize, Integer k) { 201 | if (canOptimize) { 202 | //若可优化则还原之前的保存点 203 | backToSnapshot(k); 204 | } else { 205 | //若不可优化则老老实实初始化 206 | initCtx(); 207 | } 208 | } 209 | 210 | private boolean calcInner(Calculator calculator, DiscountWrapper wrapper, List a, int i) { 211 | long price = calculator.calcWarp(context, wrapper, context.getRecords(), a.get(i), i); 212 | if (price < 0) { 213 | return false; 214 | } 215 | if (i < a.size() - 1) { 216 | int order = wrapper.getDiscountConfig().getCalculateGroup(); 217 | int nextOrder = context.getDiscountWrappers().get(a.get(i + 1)).getDiscountConfig().getCalculateGroup(); 218 | if (order > nextOrder) { 219 | //优先级不符合则跳出 220 | return false; 221 | } 222 | } 223 | return true; 224 | } 225 | 226 | /** 227 | * 根据数组顺序执行计算器 228 | */ 229 | public boolean executeCalc(DiscountContext context, List a) { 230 | Integer k = calcKey(a); 231 | boolean canOptimize = enableOptimize(a) && cache.containsKey(k); 232 | initInner(canOptimize, k); 233 | for (int i = canOptimize ? 3 : 0; i < a.size(); i++) { 234 | DiscountWrapper wrapper = context.getDiscountWrappers().get(a.get(i)); 235 | Calculator calculator = (Calculator) calculatorRouter.getService(wrapper.getType()); 236 | //路由目标的计算器实现 237 | if (canOptimize && checkIfWakeUpJump(context.getDiscountWrappers().get(a.get(2)), wrapper)) { 238 | //还原保存点后，比较保存点的最后一个优惠节点和当前优惠的优先级，如不符合则跳出 239 | break; 240 | } 241 | if (Objects.nonNull(calculator)) { 242 | //执行计算器 243 | if (!calcInner(calculator, wrapper, a, i)) { 244 | return false; 245 | } 246 | //优惠长度为5、6、7 将开启优化，只缓存走到第3个节点的部分 247 | cacheSnapshot(a, i, k); 248 | } 249 | } 250 | long curPrice = context.getCalcResult().getCurPrice(); 251 | context.getCalcResult().setCurFinalPrice(curPrice); 252 | CalcStage[] stages = context.getCalcResult().getCurStages(); 253 | return curPrice < context.getCalcResult().getFinalPrice() && (CollectionUtils.isEmpty(this.mustUseSet) || isMustUse(stages, this.mustUseSet)) || 254 | //相同最优解处理逻辑 255 | curPrice == context.getCalcResult().getFinalPrice() && (CollectionUtils.isEmpty(this.mustUseSet) || isMustUse(stages, this.mustUseSet)) && sameOptimumCondition(stages); 256 | } 257 | 258 | /** 259 | * 还原保存点后，比较保存点的最后一个优惠节点和当前优惠的优先级，如不符合则跳出 260 | * @param cachedWrap 保存点的最后一个优惠节点 261 | * @param wrapper 当前优惠节点 262 | */ 263 | private boolean checkIfWakeUpJump(DiscountWrapper cachedWrap, DiscountWrapper wrapper) { 264 | return cachedWrap.getDiscountConfig().getCalculateGroup() > wrapper.getDiscountConfig().getCalculateGroup(); 265 | } 266 | 267 | 268 | /** 269 | * 全排列计算后判断位置是否匹配 270 | * @param stages 当前stage数组 271 | * @param pos 必须使用的优惠索引 272 | * @return 273 | */ 274 | private boolean isMustUse(CalcStage[] stages, Set pos) { 275 | int c = 0; 276 | for (CalcStage stage : stages) { 277 | if (Objects.isNull(stage)) { 278 | continue; 279 | } 280 | if (pos.contains(stage.getIndex())) { 281 | c++; 282 | } 283 | } 284 | return c == pos.size(); 285 | } 286 | 287 | 288 | /** 289 | * 初始化上下文，清理上一排列留下的脏数据 290 | */ 291 | private void initCtx() { 292 | context.getCalcResult().setCurPrice(context.getOriginalPrice()); 293 | CalcStage[] curArr = context.getCalcResult().getCurStages(); 294 | //每次排列计算前初始化curStages为null 295 | Arrays.fill(curArr, null); 296 | //每次排列计算前reset usedList 中的单品价格，并清空 297 | context.getGoodsItems().forEach(this::resetItems); 298 | //清空黑名单 299 | context.getRecords().clear(); 300 | //初始化Context 301 | resetContext(context); 302 | } 303 | 304 | /** 305 | * 构建保存点 306 | * @param goods 商品列表 307 | */ 308 | private CalcState makeSnapshot(List goods) { 309 | CalcState state = new CalcState<>(); 310 | state.setCurPrice(context.getCalcResult().getCurPrice()); 311 | state.setCurStages(copyStage(context.getCalcResult().getCurStages())); 312 | state.setRecords(copyRecord(context.getRecords())); 313 | makeSnapshot(state, context); 314 | return state; 315 | } 316 | 317 | 318 | /** 319 | * 返回保存点 320 | * @param k 缓存的key 321 | */ 322 | private void backToSnapshot(Integer k) { 323 | CalcState state = (CalcState) cache.get(k); 324 | context.getCalcResult().setCurPrice(state.getCurPrice()); 325 | context.getCalcResult().setCurStages(copyStage(state.getCurStages())); 326 | context.setRecords(copyRecord(state.getRecords())); 327 | backToSnapshot(state, context); 328 | } 329 | 330 | 331 | /** 332 | * 复制stages 333 | * @param curStages 当前stages 334 | */ 335 | private CalcStage[] copyStage(CalcStage[] curStages) { 336 | CalcStage[] cs = new CalcStage[curStages.length]; 337 | System.arraycopy(curStages, 0, cs, 0, curStages.length); 338 | return cs; 339 | } 340 | 341 | /** 342 | * clone商品当前状态，转成map便于查找 343 | * @param goods 商品列表 344 | * @return 345 | */ 346 | protected Map copyGoods(List goods) { 347 | Map map = Maps.newHashMap(); 348 | for (T good : goods) { 349 | try { 350 | map.put(good.getCalculateId(), (T) good.clone()); 351 | } catch (Exception ignore) { 352 | } 353 | } 354 | return map; 355 | } 356 | 357 | /** 358 | * 复制享受过优惠的商品记录，只用到calculateId，因此不对对象进行clone 359 | * @param records 享受过优惠的商品记录 360 | */ 361 | private Map copyRecord(Map records) { 362 | return Maps.newHashMap(records); 363 | } 364 | 365 | /** 366 | * 相同最优解的处理逻辑，交给业务来实现 367 | * 368 | * @param stages 最终的stage数组 369 | * @param curStages 当前的stage数组 370 | * @return 371 | */ 372 | protected abstract boolean sameOptimumCondition(CalcStage[] curStages); 373 | 374 | /** 375 | * context参数的重置逻辑，交给业务来实现 376 | * @param context 上下文 377 | */ 378 | protected abstract void resetContext(DiscountContext context); 379 | 380 | /** 381 | * 开启缓存的条件,如 a.size>4 382 | * @param a 优惠排列 383 | */ 384 | protected abstract boolean enableOptimize(List a); 385 | 386 | /** 387 | * 商品参数的重置逻辑，交给业务来实现 388 | * @param item 单品 389 | */ 390 | protected abstract void resetItems(T item); 391 | 392 | /** 393 | * 业务将状态记录到保存点 394 | * @param state 保存点对象 395 | */ 396 | protected abstract void makeSnapshot(CalcState state, DiscountContext context); 397 | 398 | /** 399 | * 业务返回保存点状态 400 | * @param state 保存点对象 401 | */ 402 | protected abstract void backToSnapshot(CalcState state, DiscountContext context); 403 | } 404 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/precompute/PreCompute.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.precompute; 18 | 19 | import com.gch.discount.core.model.common.DiscountWrapper; 20 | import com.gch.discount.core.model.goods.GoodsItem; 21 | 22 | import java.util.List; 23 | import java.util.Map; 24 | import java.util.Set; 25 | 26 | /** 27 | * 预计算，把一些耗时操作放在Context中操作 28 | * @author: GaoSSR 29 | * @date: 2023/8 30 | */ 31 | public interface PreCompute { 32 | 33 | /** 34 | * 判断符合条件的活动类型，符合才会执行preComputeItems 35 | */ 36 | Set matchTypes(); 37 | 38 | /** 39 | * 对商品做一些复杂集合操作 40 | * @param items 当前参与优惠的商品 41 | * @param discount 当前优惠 42 | * @param preCompute 存储计算的结果 43 | */ 44 | void preComputeItems(List items, DiscountWrapper discount, Map preCompute); 45 | } 46 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/precompute/PreComputeHolder.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.precompute; 18 | 19 | import com.google.common.collect.Sets; 20 | import org.apache.commons.lang3.StringUtils; 21 | import org.reflections.Reflections; 22 | import org.springframework.core.io.FileSystemResource; 23 | import org.springframework.core.io.support.PropertiesLoaderUtils; 24 | 25 | import java.util.Objects; 26 | import java.util.Properties; 27 | import java.util.Set; 28 | 29 | /** 30 | * PreCompute实现类的加载器，会扫描calculator-core文件中的precompute.path属性 31 | * @author: GaoSSR 32 | * @date: 2023/8 33 | */ 34 | @SuppressWarnings("all") 35 | public class PreComputeHolder { 36 | public static Set COMPUTES = Sets.newHashSet(); 37 | private final static String PATH = "precompute.path"; 38 | 39 | static { 40 | Properties properties = new Properties(); 41 | try { 42 | properties = PropertiesLoaderUtils.loadProperties(new FileSystemResource(Objects.requireNonNull(PreComputeHolder.class.getClassLoader().getResource("calculator-core.properties")).getPath())); 43 | } catch (Exception ignore) { 44 | } 45 | String path = properties.getProperty(PATH); 46 | if (StringUtils.isNotBlank(path)) { 47 | Reflections reflections = new Reflections(path); 48 | Set> subTypes = reflections.getSubTypesOf(PreCompute.class); 49 | for (Class clazz : subTypes) { 50 | try { 51 | COMPUTES.add(clazz.newInstance()); 52 | } catch (Exception ignore) { 53 | } 54 | } 55 | } 56 | } 57 | } 58 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/utils/DiscountGroupUtil.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.utils; 18 | 19 | import com.gch.discount.core.model.common.DiscountGroup; 20 | import com.gch.discount.core.model.common.DiscountWrapper; 21 | import com.gch.discount.core.model.common.Item; 22 | import com.gch.discount.core.permutation.Permutation; 23 | import com.google.common.collect.Lists; 24 | import com.google.common.collect.Maps; 25 | import com.google.common.collect.Sets; 26 | import com.google.common.util.concurrent.AtomicLongMap; 27 | import org.apache.commons.collections4.CollectionUtils; 28 | import org.apache.commons.collections4.MapUtils; 29 | import org.apache.commons.lang3.tuple.Pair; 30 | import java.util.*; 31 | import java.util.stream.Collectors; 32 | 33 | /** 34 | * ID生成器，用于生成每次计算的商品id 35 | * 非线程安全，不可以在多线程共享。 每次计算创建一个，用于生成具体每一个商品的唯一ID 36 | * @author: GaoSSR 37 | * @date: 2023/7 38 | */ 39 | public class DiscountGroupUtil { 40 | 41 | private static final String EXCLUDE="exclude"; 42 | 43 | /** 44 | * 返回所有共享组 45 | * Pair的left是长度不超过 Permutation.SUPPORTEDSIZE 的内容，right是第 Permutation.SUPPORTEDSIZE+1 46 | * 种优惠即其他优惠（若有），即不参与全排列的优惠 47 | * @param groups 48 | * @param inMap 49 | * @return 50 | */ 51 | public static List,Set>> transform(List> groups, Map> inMap) { 52 | List,Set>> resultList = Lists.newArrayList(); 53 | List> list = mergeGroups(groups,inMap); 54 | if(CollectionUtils.isEmpty(list)){ 55 | return Lists.newArrayList(); 56 | } 57 | for(List items:list){ 58 | Set discountWrappers = items.stream().map(x->{ 59 | if(inMap.containsKey(x.getType())){ 60 | Map m=inMap.get(x.getType()); 61 | if(m.containsKey(x.getId())){ 62 | return m.get(x.getId()); 63 | } 64 | } 65 | return null; 66 | }).filter(Objects::nonNull).collect(Collectors.toSet()); 67 | if(CollectionUtils.isNotEmpty(discountWrappers) && discountWrappers.size()>=2){ 68 | if(discountWrappers.size()> Permutation.SUPPORTEDSIZE) { 69 | resultList.add(balanceLR(discountWrappers)); 70 | }else{ 71 | resultList.add(Pair.of(discountWrappers, Sets.newHashSet())); 72 | } 73 | } 74 | } 75 | //优先计算短的共享组 76 | return resultList.stream().sorted(Comparator.comparing(x->x.getLeft().size(),Collections.reverseOrder())).collect(Collectors.toList()); 77 | } 78 | 79 | /** 80 | * 保证mustuse的优惠进入left集合 81 | * @param discountWrappers 当前可用优惠 82 | */ 83 | private static Pair,Set> balanceLR(Set discountWrappers){ 84 | Set left=Sets.newHashSet(); 85 | Set right=Sets.newHashSet(); 86 | for(DiscountWrapper wrapper:discountWrappers){ 87 | if(wrapper.isMustUse()){ 88 | left.add(wrapper); 89 | }else{ 90 | right.add(wrapper); 91 | } 92 | } 93 | if(left.size() it = right.iterator(); 96 | while (c>0&&it.hasNext()){ 97 | DiscountWrapper w = it.next(); 98 | left.add(w); 99 | it.remove(); 100 | c--; 101 | } 102 | }else if(left.size()>Permutation.SUPPORTEDSIZE){ 103 | int c = left.size()-Permutation.SUPPORTEDSIZE; 104 | Iterator it = left.iterator(); 105 | while (c>0&&it.hasNext()){ 106 | DiscountWrapper w = it.next(); 107 | right.add(w); 108 | it.remove(); 109 | c--; 110 | } 111 | } 112 | return Pair.of(left,right); 113 | } 114 | 115 | /** 116 | * 合并规则转化为共享组 117 | * @param groups 所有规则大组 118 | * @param inMap 实际可用优惠 119 | */ 120 | private static List> mergeGroups(List> groups,Map> inMap){ 121 | if(CollectionUtils.isEmpty(groups) || MapUtils.isEmpty(inMap)){ 122 | return null; 123 | } 124 | //resultList 接收最终的结果 125 | List> resultList = Lists.newArrayList(); 126 | //ctx 全局计数器，对于独立共享组多次被使用进行删除（唯一需要去重的场景） 127 | AtomicLongMap ctx = AtomicLongMap.create(); 128 | //索引，存放可能需要删除的key 129 | Map idxMap = Maps.newHashMap(); 130 | for(List list:groups){ 131 | mergeGroup(list,inMap,ctx,idxMap,resultList); 132 | } 133 | Map map = ctx.asMap(); 134 | List orderedList = Lists.newArrayList(); 135 | for(Map.Entry e:map.entrySet()){ 136 | Integer idx = idxMap.get(e.getKey()); 137 | if(Objects.nonNull(idx)&&e.getValue()>1){ 138 | orderedList.add(idxMap.get(e.getKey())); 139 | } 140 | } 141 | orderedList.sort(Collections.reverseOrder()); 142 | //从后往前删除，否则索引会出问题 143 | for(Integer i:orderedList){ 144 | resultList.remove(i.intValue()); 145 | } 146 | return resultList.stream().filter(CollectionUtils::isNotEmpty).collect(Collectors.toList()); 147 | } 148 | 149 | private static void mergeGroup(List groups,Map> inMap, 150 | AtomicLongMap ctx,Map idxMap, 151 | List> resultList){ 152 | if(CollectionUtils.isEmpty(groups)){ 153 | return ; 154 | } 155 | List xList = groups.get(0).filterItems(inMap); 156 | if(CollectionUtils.isEmpty(xList)){ 157 | return ; 158 | } 159 | if(groups.size()==1){ 160 | //必然是共享组 161 | //存入全局上下文，去重时使用，这里累计次数，若次数大于1，需要在最外层移除此共享组 162 | String key = uniqueKey(xList); 163 | ctx.incrementAndGet(key); 164 | //记录索引,以便删除 165 | idxMap.put(key,resultList.size()); 166 | resultList.add(xList); 167 | }else{ 168 | //yList必然是互斥的 169 | List yList = groups.get(1).filterItems(inMap); 170 | if(Objects.equals(EXCLUDE,groups.get(0).getRelation())){ 171 | //产品设计规避了重复的情况，无需去重 172 | for(Item item:xList){ 173 | for(Item item1:yList){ 174 | resultList.add(Lists.newArrayList(item,item1)); 175 | } 176 | } 177 | }else{ 178 | //存入全局上下文，去重时使用，这里累计次数，若次数大于1，需要在最外层移除此共享组 179 | String k = uniqueKey(xList); 180 | for(Item item:yList){ 181 | ctx.incrementAndGet(k); 182 | List xCopy = Lists.newArrayList(xList); 183 | xCopy.add(item); 184 | resultList.add(xCopy); 185 | } 186 | } 187 | } 188 | } 189 | 190 | private static String uniqueKey(List list){ 191 | return list.stream().map(i->i.getType()+i.getId()).sorted().collect(Collectors.joining()); 192 | } 193 | 194 | } 195 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/utils/IdGenerator.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.utils; 18 | 19 | /** 20 | * ID生成器，用于生成每次计算的商品id 21 | * 非线程安全，不可在多线程共享。 每次计算创建一个，用于生成具体每一个商品的唯一ID 22 | * @author: GaoSSR 23 | * @date: 2023/7 24 | */ 25 | public class IdGenerator { 26 | 27 | /** 28 | * 新建一个对象，默认构造 29 | */ 30 | public static IdGenerator getInstance() { 31 | return new IdGenerator(); 32 | } 33 | 34 | /** 35 | * 当前ID，默认从1开始 36 | */ 37 | private long currentId = 1; 38 | 39 | /** 40 | * 按序列生成一个ID 41 | */ 42 | public long nextId() { 43 | return currentId++; 44 | } 45 | } 46 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/core/utils/LimitingUtil.java: -------------------------------------------------------------------------------- 1 | /* 2 | * Copyright 2023 GaoSSR 3 | * 4 | * Licensed under the Apache License, Version 2.0 (the "License"); 5 | * you may not use this file except in compliance with the License. 6 | * You may obtain a copy of the License at 7 | * 8 | * http://www.apache.org/licenses/LICENSE-2.0 9 | * 10 | * Unless required by applicable law or agreed to in writing, software 11 | * distributed under the License is distributed on an "AS IS" BASIS, 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | * See the License for the specific language governing permissions and 14 | * limitations under the License. 15 | */ 16 | 17 | package com.gch.discount.core.utils; 18 | 19 | /** 20 | * 统计计算次数的工具，在机器负载较大时，作为放弃后面计算的条件 21 | * @author: GaoSSR 22 | * @date: 2023/8 23 | */ 24 | public class LimitingUtil { 25 | 26 | /** 27 | * 统计计算次数 28 | * 根据性能压测结果，对于多个共享组来说是必要的 29 | * @param length 共享组的长度 30 | */ 31 | public static int count(int length){ 32 | switch (length){ 33 | case 1:return 1; 34 | //下面的计算公式是 x!*x 35 | case 2:return 4; 36 | case 3:return 18; 37 | //下面的计算公式是 x!*(x-3)+p(x,3) 38 | case 4:return 48; 39 | case 5:return 300; 40 | case 6:return 2280; 41 | case 7:return 20370; 42 | default:return 0; 43 | } 44 | } 45 | } 46 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/App.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo; 2 | 3 | import org.springframework.boot.SpringApplication; 4 | import org.springframework.boot.autoconfigure.SpringBootApplication; 5 | import org.springframework.context.annotation.ComponentScan; 6 | 7 | @SpringBootApplication 8 | @ComponentScan("com.gch.discount") 9 | public class App { 10 | public static void main(String[] args) { 11 | SpringApplication.run(App.class, args); 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/Flowable.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz; 2 | 3 | import com.gch.discount.core.model.common.CalcStage; 4 | import com.gch.discount.core.model.common.CalcState; 5 | import com.gch.discount.core.model.common.DiscountContext; 6 | import com.gch.discount.core.model.goods.GoodsItem; 7 | import com.gch.discount.core.permutation.Permutation; 8 | import com.gch.discount.demo.biz.constant.Constant; 9 | 10 | import java.util.List; 11 | 12 | public class Flowable extends Permutation { 13 | @Override 14 | protected boolean enableOptimize(List a) { 15 | return false; 16 | } 17 | 18 | @Override 19 | protected boolean sameOptimumCondition(CalcStage[] curStages) { 20 | return false; 21 | } 22 | 23 | @Override 24 | protected void resetContext(DiscountContext context) { 25 | 26 | } 27 | 28 | @Override 29 | protected void resetItems(GoodsItem item) { 30 | item.getExtra().put(Constant.UPDATEABLEPRICE, item.getSalePrice()); 31 | } 32 | 33 | @Override 34 | protected void makeSnapshot(CalcState state, DiscountContext context) { 35 | 36 | } 37 | 38 | @Override 39 | protected void backToSnapshot(CalcState state, DiscountContext context) { 40 | 41 | } 42 | } 43 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/TestController.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz; 2 | 3 | import com.gch.discount.core.enums.GroupRelation; 4 | import com.gch.discount.core.model.common.*; 5 | import com.gch.discount.core.model.goods.GoodsInfo; 6 | import com.gch.discount.core.model.goods.GoodsItem; 7 | import com.gch.discount.core.utils.DiscountGroupUtil; 8 | import com.gch.discount.core.utils.IdGenerator; 9 | import com.gch.discount.core.utils.LimitingUtil; 10 | import com.gch.discount.demo.biz.constant.Constant; 11 | import com.google.common.collect.ImmutableMap; 12 | import com.google.common.collect.Lists; 13 | import org.apache.commons.lang3.tuple.Pair; 14 | import org.springframework.stereotype.Controller; 15 | import org.springframework.web.bind.annotation.RequestMapping; 16 | import org.springframework.web.bind.annotation.ResponseBody; 17 | import com.gch.discount.core.aware.CalculatorRouter; 18 | 19 | import java.util.*; 20 | import java.util.stream.Collectors; 21 | 22 | @Controller 23 | public class TestController { 24 | private final CalculatorRouter calculatorRouter; 25 | 26 | public TestController(CalculatorRouter calculatorRouter) { 27 | this.calculatorRouter = calculatorRouter; 28 | } 29 | 30 | @RequestMapping("test") 31 | @ResponseBody 32 | public Object test() { 33 | //mock商品 34 | List items = mockItems(); 35 | //mock组关系并转化为共享组 36 | List, Set>> pairs = transform(mockGroups()); 37 | //全局最优计算过程 38 | List globalStages = Lists.newArrayList(); 39 | int count = 0; 40 | //订单总金额 41 | long totalPrice = items.stream().mapToLong(GoodsInfo::getSalePrice).sum(); 42 | long globalPrice = totalPrice; 43 | //构建计算流 44 | Flowable flowable = (Flowable) new Flowable().build(calculatorRouter); 45 | for (Pair, Set> set : pairs) { 46 | //统计算力 47 | count += LimitingUtil.count(set.getLeft().size()); 48 | if (count > 100000) { 49 | break; 50 | } 51 | List wrappers = Lists.newArrayList(set.getLeft()); 52 | DiscountContext ctx = DiscountContext.create(totalPrice, Lists.newArrayList(items), wrappers); 53 | flowable.perm(ctx); 54 | if (ctx.getCalcResult().getFinalPrice() < globalPrice) { 55 | globalStages = Arrays.asList(ctx.getCalcResult().getStages()); 56 | globalPrice = ctx.getCalcResult().getFinalPrice(); 57 | } 58 | } 59 | return Pair.of(globalPrice, globalStages); 60 | } 61 | 62 | private List> mockGroups() { 63 | List> groups = Lists.newArrayList(); 64 | DiscountGroup group = new DiscountGroup(); 65 | group.setRelation(GroupRelation.SHARE.getType()); 66 | group.setItems(Lists.newArrayList(new Item("zhekou", "1"), new Item("manjian", "2"), new Item("manzeng", "3"))); 67 | groups.add(Lists.newArrayList(group)); 68 | return groups; 69 | } 70 | 71 | private List mockItems() { 72 | IdGenerator idGenerator = IdGenerator.getInstance(); 73 | GoodsInfo goodsInfo = GoodsInfo.of(1001L, 2001L, null, 4, 20 * 100, "产品1", null); 74 | GoodsInfo goodsInfo2 = GoodsInfo.of(1001L, 2002L, null, 2, 10 * 100, "产品1", null); 75 | List items = GoodsItem.generateItems(goodsInfo, idGenerator, x -> x.getExtra().put(Constant.UPDATEABLEPRICE, x.getSalePrice())); 76 | items.addAll(GoodsItem.generateItems(goodsInfo2, idGenerator, x -> x.getExtra().put(Constant.UPDATEABLEPRICE, x.getSalePrice()))); 77 | return items; 78 | } 79 | 80 | private List, Set>> transform(List> groups) { 81 | List wrapperList = Lists.newArrayList( 82 | DiscountWrapper.of("zhekou", "1", "折扣", false, new DiscountConfig()), 83 | DiscountWrapper.of("manjian", "2", "满减", false, new DiscountConfig()) 84 | ); 85 | Map> inMap = wrapperList.stream().collect(Collectors.toMap(DiscountWrapper::getType, x -> ImmutableMap.of(x.getId(), x))); 86 | return DiscountGroupUtil.transform(groups, inMap); 87 | } 88 | } 89 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/calc/ManjianCalc.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz.calc; 2 | 3 | import com.gch.discount.core.discount.impl.AbstractCalculator; 4 | import com.gch.discount.core.model.common.CalcStage; 5 | import com.gch.discount.core.model.common.DiscountContext; 6 | import com.gch.discount.core.model.common.DiscountWrapper; 7 | import com.gch.discount.core.model.goods.GoodsItem; 8 | import com.gch.discount.demo.biz.constant.Constant; 9 | import com.google.common.collect.Lists; 10 | import org.springframework.stereotype.Component; 11 | 12 | import java.util.List; 13 | import java.util.Map; 14 | 15 | @Component("manjian") 16 | public class ManjianCalc extends AbstractCalculator { 17 | @Override 18 | public long calc(DiscountContext context, DiscountWrapper discountWrapper, Map records, long prevStagePrice, CalcStage curStage) { 19 | List items = Lists.newArrayList(context.getDiscountItemGroup().get(discountWrapper.getId())); 20 | if (prevStagePrice >= 100 * 100) { 21 | prevStagePrice = prevStagePrice - 20 * 100; 22 | } 23 | //均摊 24 | for (GoodsItem item : items) { 25 | item.getExtra().put(Constant.UPDATEABLEPRICE, (long) item.getExtra().get(Constant.UPDATEABLEPRICE) - (long) (20 * 100 / items.size())); 26 | } 27 | return prevStagePrice; 28 | } 29 | } 30 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/calc/ZhekouCalc.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz.calc; 2 | 3 | import com.gch.discount.core.discount.impl.AbstractCalculator; 4 | import com.gch.discount.core.model.common.CalcStage; 5 | import com.gch.discount.core.model.common.DiscountContext; 6 | import com.gch.discount.core.model.common.DiscountWrapper; 7 | import com.gch.discount.core.model.goods.GoodsItem; 8 | import com.gch.discount.demo.biz.constant.Constant; 9 | import com.google.common.collect.Lists; 10 | import org.apache.commons.collections4.CollectionUtils; 11 | import org.springframework.stereotype.Component; 12 | 13 | import java.util.Collection; 14 | import java.util.List; 15 | import java.util.Map; 16 | 17 | @Component("zhekou") 18 | @SuppressWarnings("unchecked") 19 | public class ZhekouCalc extends AbstractCalculator { 20 | @Override 21 | public long calc(DiscountContext context, DiscountWrapper discountWrapper, Map records, long prevStagePrice, CalcStage curStage) { 22 | List items = Lists.newArrayList(context.getDiscountItemGroup().get(discountWrapper.getId())); 23 | Map> map = (Map>) context.getPreCompute().get("GroupBySkuIdPreCompute"); 24 | long maxPrice = 0L; 25 | Collection group = CollectionUtils.EMPTY_COLLECTION; 26 | for (Collection c : map.values()) { 27 | long tmp = (long) c.iterator().next().getExtra().get(Constant.UPDATEABLEPRICE); 28 | if (tmp > maxPrice) { 29 | maxPrice = tmp; 30 | group = c; 31 | } 32 | } 33 | long discount = (long) (maxPrice * group.size() * 0.2); 34 | //均摊 35 | for (GoodsItem item : group) { 36 | item.getExtra().put(Constant.UPDATEABLEPRICE, (long) item.getExtra().get(Constant.UPDATEABLEPRICE) - discount / items.size()); 37 | } 38 | return prevStagePrice - discount; 39 | } 40 | } 41 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/constant/Constant.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz.constant; 2 | 3 | public class Constant { 4 | 5 | public static final String UPDATEABLEPRICE = "updateablePrice"; 6 | 7 | } 8 | -------------------------------------------------------------------------------- /src/main/java/com/gch/discount/demo/biz/precompute/PreGroupBy.java: -------------------------------------------------------------------------------- 1 | package com.gch.discount.demo.biz.precompute; 2 | 3 | import com.gch.discount.core.model.common.DiscountWrapper; 4 | import com.gch.discount.core.model.goods.GoodsInfo; 5 | import com.gch.discount.core.model.goods.GoodsItem; 6 | import com.gch.discount.core.precompute.PreCompute; 7 | import com.google.common.collect.Sets; 8 | 9 | import java.util.List; 10 | import java.util.Map; 11 | import java.util.Set; 12 | import java.util.stream.Collectors; 13 | 14 | public class PreGroupBy implements PreCompute { 15 | @Override 16 | public Set matchTypes() { 17 | return Sets.newHashSet("zhekou"); 18 | } 19 | 20 | @Override 21 | public void preComputeItems(List items, DiscountWrapper discount, Map preCompute) { 22 | preCompute.put("GroupBySkuIdPreCompute", items.stream().collect(Collectors.groupingBy 23 | (GoodsInfo::getSkuId, Collectors.collectingAndThen(Collectors.toList(), 24 | e -> e.stream().sorted().collect(Collectors.toList()))))); 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /src/main/resources/calculator-core.properties: -------------------------------------------------------------------------------- 1 | precompute.path=com.gch.discount.demo.biz --------------------------------------------------------------------------------