Redis 抽獎大轉盤的實戰示例
1. 項目介紹
這是一個基於Spring boot + Mybatis Plus + Redis 的簡單案例。
主要是將活動內容、獎品信息、記錄信息等緩存到Redis中,然後所有的抽獎過程全部從Redis中做數據的操作。
大致內容很簡單,具體操作下面慢慢分析。
2. 項目演示
話不多說,首先上圖看看項目效果,如果覺得還行的話咱們就來看看他具體是怎麼實現的。
3. 表結構
該項目包含以下四張表,分別是活動表、獎項表、獎品表以及中獎記錄表。具體的SQL會在文末給出。
4. 項目搭建
咱們首先先搭建一個標準的Spring boot 項目,直接IDEA創建,然後選擇一些相關的依賴即可。
4.1 依賴
該項目主要用到瞭:Redis,thymeleaf,mybatis-plus等依賴。
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.4.3</version> </dependency> <dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-generator</artifactId> <version>3.4.1</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.72</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.22</version> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-lang3</artifactId> <version>3.9</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.12</version> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>org.mapstruct</groupId> <artifactId>mapstruct</artifactId> <version>1.4.2.Final</version> </dependency> <dependency> <groupId>org.mapstruct</groupId> <artifactId>mapstruct-jdk8</artifactId> <version>1.4.2.Final</version> </dependency> <dependency> <groupId>org.mapstruct</groupId> <artifactId>mapstruct-processor</artifactId> <version>1.4.2.Final</version> </dependency> <dependency> <groupId>joda-time</groupId> <artifactId>joda-time</artifactId> <version>2.10.6</version> </dependency> </dependencies>
4.2 YML配置
依賴引入之後,我們需要進行相應的配置:數據庫連接信息、Redis、mybatis-plus、線程池等。
server: port: 8080 servlet: context-path: / spring: datasource: druid: url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false username: root password: 123456 driver-class-name: com.mysql.cj.jdbc.Driver initial-size: 30 max-active: 100 min-idle: 10 max-wait: 60000 time-between-eviction-runs-millis: 60000 min-evictable-idle-time-millis: 300000 validation-query: SELECT 1 FROM DUAL test-while-idle: true test-on-borrow: false test-on-return: false filters: stat,wall redis: port: 6379 host: 127.0.0.1 lettuce: pool: max-active: -1 max-idle: 2000 max-wait: -1 min-idle: 1 time-between-eviction-runs: 5000 mvc: view: prefix: classpath:/templates/ suffix: .html # mybatis-plus mybatis-plus: configuration: map-underscore-to-camel-case: true auto-mapping-behavior: full mapper-locations: classpath*:mapper/**/*Mapper.xml # 線程池 async: executor: thread: core-pool-size: 6 max-pool-size: 12 queue-capacity: 100000 name-prefix: lottery-service-
4.3 代碼生成
這邊我們可以直接使用mybatis-plus的代碼生成器幫助我們生成一些基礎的業務代碼,避免這些重復的體力活。
這邊貼出相關代碼,直接修改數據庫連接信息、相關包名模塊名即可。
public class MybatisPlusGeneratorConfig { public static void main(String[] args) { // 代碼生成器 AutoGenerator mpg = new AutoGenerator(); // 全局配置 GlobalConfig gc = new GlobalConfig(); String projectPath = System.getProperty("user.dir"); gc.setOutputDir(projectPath + "/src/main/java"); gc.setAuthor("chen"); gc.setOpen(false); //實體屬性 Swagger2 註解 gc.setSwagger2(false); mpg.setGlobalConfig(gc); // 數據源配置 DataSourceConfig dsc = new DataSourceConfig(); dsc.setUrl("jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true"); dsc.setDriverName("com.mysql.cj.jdbc.Driver"); dsc.setUsername("root"); dsc.setPassword("123456"); mpg.setDataSource(dsc); // 包配置 PackageConfig pc = new PackageConfig(); // pc.setModuleName(scanner("模塊名")); pc.setParent("com.example.lottery"); pc.setEntity("dal.model"); pc.setMapper("dal.mapper"); pc.setService("service"); pc.setServiceImpl("service.impl"); mpg.setPackageInfo(pc); // 配置模板 TemplateConfig templateConfig = new TemplateConfig(); templateConfig.setXml(null); mpg.setTemplate(templateConfig); // 策略配置 StrategyConfig strategy = new StrategyConfig(); strategy.setNaming(NamingStrategy.underline_to_camel); strategy.setColumnNaming(NamingStrategy.underline_to_camel); strategy.setSuperEntityClass("com.baomidou.mybatisplus.extension.activerecord.Model"); strategy.setEntityLombokModel(true); strategy.setRestControllerStyle(true); strategy.setEntityLombokModel(true); // 公共父類 // strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController"); // 寫於父類中的公共字段 // strategy.setSuperEntityColumns("id"); strategy.setInclude(scanner("lottery,lottery_item,lottery_prize,lottery_record").split(",")); strategy.setControllerMappingHyphenStyle(true); strategy.setTablePrefix(pc.getModuleName() + "_"); mpg.setStrategy(strategy); mpg.setTemplateEngine(new FreemarkerTemplateEngine()); mpg.execute(); } public static String scanner(String tip) { Scanner scanner = new Scanner(System.in); StringBuilder help = new StringBuilder(); help.append("請輸入" + tip + ":"); System.out.println(help.toString()); if (scanner.hasNext()) { String ipt = scanner.next(); if (StringUtils.isNotEmpty(ipt)) { return ipt; } } throw new MybatisPlusException("請輸入正確的" + tip + "!"); } }
4.4 Redis 配置
我們如果在代碼中使用 RedisTemplate 的話,需要添加相關配置,將其註入到Spring容器中。
@Configuration public class RedisTemplateConfig { @Bean public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory) { RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>(); redisTemplate.setConnectionFactory(redisConnectionFactory); // 使用Jackson2JsonRedisSerialize 替換默認序列化 Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class); ObjectMapper objectMapper = new ObjectMapper(); objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); SimpleModule simpleModule = new SimpleModule(); simpleModule.addSerializer(DateTime.class, new JodaDateTimeJsonSerializer()); simpleModule.addDeserializer(DateTime.class, new JodaDateTimeJsonDeserializer()); objectMapper.registerModule(simpleModule); jackson2JsonRedisSerializer.setObjectMapper(objectMapper); // 設置value的序列化規則和 key的序列化規則 redisTemplate.setValueSerializer(jackson2JsonRedisSerializer); redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setHashKeySerializer(new StringRedisSerializer()); redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer); redisTemplate.afterPropertiesSet(); return redisTemplate; } } class JodaDateTimeJsonSerializer extends JsonSerializer<DateTime> { @Override public void serialize(DateTime dateTime, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException { jsonGenerator.writeString(dateTime.toString("yyyy-MM-dd HH:mm:ss")); } } class JodaDateTimeJsonDeserializer extends JsonDeserializer<DateTime> { @Override public DateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException { String dateString = jsonParser.readValueAs(String.class); DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss"); return dateTimeFormatter.parseDateTime(dateString); } }
4.5 常量管理
由於代碼中會用到一些共有的常量,我們應該將其抽離出來。
public class LotteryConstants { /** * 表示正在抽獎的用戶標記 */ public final static String DRAWING = "DRAWING"; /** * 活動標記 LOTTERY:lotteryID */ public final static String LOTTERY = "LOTTERY"; /** * 獎品數據 LOTTERY_PRIZE:lotteryID:PrizeId */ public final static String LOTTERY_PRIZE = "LOTTERY_PRIZE"; /** * 默認獎品數據 DEFAULT_LOTTERY_PRIZE:lotteryID */ public final static String DEFAULT_LOTTERY_PRIZE = "DEFAULT_LOTTERY_PRIZE"; public enum PrizeTypeEnum { THANK(-1), NORMAL(1), UNIQUE(2); private int value; private PrizeTypeEnum(int value) { this.value = value; } public int getValue() { return this.value; } } /** * 獎項緩存:LOTTERY_ITEM:LOTTERY_ID */ public final static String LOTTERY_ITEM = "LOTTERY_ITEM"; /** * 默認獎項: DEFAULT_LOTTERY_ITEM:LOTTERY_ID */ public final static String DEFAULT_LOTTERY_ITEM = "DEFAULT_LOTTERY_ITEM"; }
public enum ReturnCodeEnum { SUCCESS("0000", "成功"), LOTTER_NOT_EXIST("9001", "指定抽獎活動不存在"), LOTTER_FINISH("9002", "活動已結束"), LOTTER_REPO_NOT_ENOUGHT("9003", "當前獎品庫存不足"), LOTTER_ITEM_NOT_INITIAL("9004", "獎項數據未初始化"), LOTTER_DRAWING("9005", "上一次抽獎還未結束"), REQUEST_PARAM_NOT_VALID("9998", "請求參數不正確"), SYSTEM_ERROR("9999", "系統繁忙,請稍後重試"); private String code; private String msg; private ReturnCodeEnum(String code, String msg) { this.code = code; this.msg = msg; } public String getCode() { return code; } public String getMsg() { return msg; } public String getCodeString() { return getCode() + ""; } }
對Redis中的key進行統一的管理。
public class RedisKeyManager { /** * 正在抽獎的key * * @param accountIp * @return */ public static String getDrawingRedisKey(String accountIp) { return new StringBuilder(LotteryConstants.DRAWING).append(":").append(accountIp).toString(); } /** * 獲取抽獎活動的key * * @param id * @return */ public static String getLotteryRedisKey(Integer id) { return new StringBuilder(LotteryConstants.LOTTERY).append(":").append(id).toString(); } /** * 獲取指定活動下的所有獎品數據 * * @param lotteryId * @return */ public static String getLotteryPrizeRedisKey(Integer lotteryId) { return new StringBuilder(LotteryConstants.LOTTERY_PRIZE).append(":").append(lotteryId).toString(); } public static String getLotteryPrizeRedisKey(Integer lotteryId, Integer prizeId) { return new StringBuilder(LotteryConstants.LOTTERY_PRIZE).append(":").append(lotteryId).append(":").append(prizeId).toString(); } public static String getDefaultLotteryPrizeRedisKey(Integer lotteryId) { return new StringBuilder(LotteryConstants.DEFAULT_LOTTERY_PRIZE).append(":").append(lotteryId).toString(); } public static String getLotteryItemRedisKey(Integer lotteryId) { return new StringBuilder(LotteryConstants.LOTTERY_ITEM).append(":").append(lotteryId).toString(); } public static String getDefaultLotteryItemRedisKey(Integer lotteryId) { return new StringBuilder(LotteryConstants.DEFAULT_LOTTERY_ITEM).append(":").append(lotteryId).toString(); } }
4.6 業務代碼
4.6.1 抽獎接口
我們首先編寫抽獎接口,根據前臺傳的參數查詢到具體的活動,然後進行相應的操作。(當然,前端直接是寫死的/lottery/1)
@GetMapping("/{id}") public ResultResp<LotteryItemVo> doDraw(@PathVariable("id") Integer id, HttpServletRequest request) { String accountIp = CusAccessObjectUtil.getIpAddress(request); log.info("begin LotteryController.doDraw,access user {}, lotteryId,{}:", accountIp, id); ResultResp<LotteryItemVo> resultResp = new ResultResp<>(); try { //判斷當前用戶上一次抽獎是否結束 checkDrawParams(id, accountIp); //抽獎 DoDrawDto dto = new DoDrawDto(); dto.setAccountIp(accountIp); dto.setLotteryId(id); lotteryService.doDraw(dto); //返回結果設置 resultResp.setCode(ReturnCodeEnum.SUCCESS.getCode()); resultResp.setMsg(ReturnCodeEnum.SUCCESS.getMsg()); //對象轉換 resultResp.setResult(lotteryConverter.dto2LotteryItemVo(dto)); } catch (Exception e) { return ExceptionUtil.handlerException4biz(resultResp, e); } finally { //清除占位標記 redisTemplate.delete(RedisKeyManager.getDrawingRedisKey(accountIp)); } return resultResp; } private void checkDrawParams(Integer id, String accountIp) { if (null == id) { throw new RewardException(ReturnCodeEnum.REQUEST_PARAM_NOT_VALID.getCode(), ReturnCodeEnum.REQUEST_PARAM_NOT_VALID.getMsg()); } //采用setNx命令,判斷當前用戶上一次抽獎是否結束 Boolean result = redisTemplate.opsForValue().setIfAbsent(RedisKeyManager.getDrawingRedisKey(accountIp), "1", 60, TimeUnit.SECONDS); //如果為false,說明上一次抽獎還未結束 if (!result) { throw new RewardException(ReturnCodeEnum.LOTTER_DRAWING.getCode(), ReturnCodeEnum.LOTTER_DRAWING.getMsg()); } }
為瞭避免用戶重復點擊抽獎,所以我們通過Redis來避免這種問題,用戶每次抽獎的時候,通過setNx給用戶排隊並設置過期時間;如果用戶點擊多次抽獎,Redis設置值的時候發現該用戶上次抽獎還未結束則拋出異常。
最後用戶抽獎成功的話,記得清除該標記,從而用戶能夠繼續抽獎。
4.6.2 初始化數據
從抽獎入口進來,校驗成功以後則開始業務操作。
@Override public void doDraw(DoDrawDto drawDto) throws Exception { RewardContext context = new RewardContext(); LotteryItem lotteryItem = null; try { //JUC工具 需要等待線程結束之後才能運行 CountDownLatch countDownLatch = new CountDownLatch(1); //判斷活動有效性 Lottery lottery = checkLottery(drawDto); //發佈事件,用來加載指定活動的獎品信息 applicationContext.publishEvent(new InitPrizeToRedisEvent(this, lottery.getId(), countDownLatch)); //開始抽獎 lotteryItem = doPlay(lottery); //記錄獎品並扣減庫存 countDownLatch.await(); //等待獎品初始化完成 String key = RedisKeyManager.getLotteryPrizeRedisKey(lottery.getId(), lotteryItem.getPrizeId()); int prizeType = Integer.parseInt(redisTemplate.opsForHash().get(key, "prizeType").toString()); context.setLottery(lottery); context.setLotteryItem(lotteryItem); context.setAccountIp(drawDto.getAccountIp()); context.setKey(key); //調整庫存及記錄中獎信息 AbstractRewardProcessor.rewardProcessorMap.get(prizeType).doReward(context); } catch (UnRewardException u) { //表示因為某些問題未中獎,返回一個默認獎項 context.setKey(RedisKeyManager.getDefaultLotteryPrizeRedisKey(lotteryItem.getLotteryId())); lotteryItem = (LotteryItem) redisTemplate.opsForValue().get(RedisKeyManager.getDefaultLotteryItemRedisKey(lotteryItem.getLotteryId())); context.setLotteryItem(lotteryItem); AbstractRewardProcessor.rewardProcessorMap.get(LotteryConstants.PrizeTypeEnum.THANK.getValue()).doReward(context); } //拼接返回數據 drawDto.setLevel(lotteryItem.getLevel()); drawDto.setPrizeName(context.getPrizeName()); drawDto.setPrizeId(context.getPrizeId()); }
首先我們通過CountDownLatch來保證商品初始化的順序,關於CountDownLatch可以查看 JUC工具 該文章。
然後我們需要檢驗一下活動的有效性,確保活動未結束。
檢驗活動通過後則通過ApplicationEvent 事件實現獎品數據的加載,將其存入Redis中。或者通過ApplicationRunner在程序啟動時獲取相關數據。我們這使用的是事件機制。ApplicationRunner 的相關代碼在下文我也順便貼出。
事件機制
public class InitPrizeToRedisEvent extends ApplicationEvent { private Integer lotteryId; private CountDownLatch countDownLatch; public InitPrizeToRedisEvent(Object source, Integer lotteryId, CountDownLatch countDownLatch) { super(source); this.lotteryId = lotteryId; this.countDownLatch = countDownLatch; } public Integer getLotteryId() { return lotteryId; } public void setLotteryId(Integer lotteryId) { this.lotteryId = lotteryId; } public CountDownLatch getCountDownLatch() { return countDownLatch; } public void setCountDownLatch(CountDownLatch countDownLatch) { this.countDownLatch = countDownLatch; } }
有瞭事件機制,我們還需要一個監聽事件,用來初始化相關數據信息。具體業務邏輯大傢可以參考下代碼,有相關的註釋信息,主要就是將數據庫中的數據添加進redis中,需要註意的是,我們為瞭保證原子性,是通過HASH來存儲數據的,這樣之後庫存扣減的時候就可以通過opsForHash來保證其原子性。
當初始化獎品信息之後,則通過countDown()方法表名執行完成,業務代碼中線程阻塞的地方可以繼續執行瞭。
@Slf4j @Component public class InitPrizeToRedisListener implements ApplicationListener<InitPrizeToRedisEvent> { @Autowired RedisTemplate redisTemplate; @Autowired LotteryPrizeMapper lotteryPrizeMapper; @Autowired LotteryItemMapper lotteryItemMapper; @Override public void onApplicationEvent(InitPrizeToRedisEvent initPrizeToRedisEvent) { log.info("begin InitPrizeToRedisListener," + initPrizeToRedisEvent); Boolean result = redisTemplate.opsForValue().setIfAbsent(RedisKeyManager.getLotteryPrizeRedisKey(initPrizeToRedisEvent.getLotteryId()), "1"); //已經初始化到緩存中瞭,不需要再次緩存 if (!result) { log.info("already initial"); initPrizeToRedisEvent.getCountDownLatch().countDown(); return; } QueryWrapper<LotteryItem> lotteryItemQueryWrapper = new QueryWrapper<>(); lotteryItemQueryWrapper.eq("lottery_id", initPrizeToRedisEvent.getLotteryId()); List<LotteryItem> lotteryItems = lotteryItemMapper.selectList(lotteryItemQueryWrapper); //如果指定的獎品沒有瞭,會生成一個默認的獎項 LotteryItem defaultLotteryItem = lotteryItems.parallelStream().filter(o -> o.getDefaultItem().intValue() == 1).findFirst().orElse(null); Map<String, Object> lotteryItemMap = new HashMap<>(16); lotteryItemMap.put(RedisKeyManager.getLotteryItemRedisKey(initPrizeToRedisEvent.getLotteryId()), lotteryItems); lotteryItemMap.put(RedisKeyManager.getDefaultLotteryItemRedisKey(initPrizeToRedisEvent.getLotteryId()), defaultLotteryItem); redisTemplate.opsForValue().multiSet(lotteryItemMap); QueryWrapper queryWrapper = new QueryWrapper(); queryWrapper.eq("lottery_id", initPrizeToRedisEvent.getLotteryId()); List<LotteryPrize> lotteryPrizes = lotteryPrizeMapper.selectList(queryWrapper); //保存一個默認獎項 AtomicReference<LotteryPrize> defaultPrize = new AtomicReference<>(); lotteryPrizes.stream().forEach(lotteryPrize -> { if (lotteryPrize.getId().equals(defaultLotteryItem.getPrizeId())) { defaultPrize.set(lotteryPrize); } String key = RedisKeyManager.getLotteryPrizeRedisKey(initPrizeToRedisEvent.getLotteryId(), lotteryPrize.getId()); setLotteryPrizeToRedis(key, lotteryPrize); }); String key = RedisKeyManager.getDefaultLotteryPrizeRedisKey(initPrizeToRedisEvent.getLotteryId()); setLotteryPrizeToRedis(key, defaultPrize.get()); initPrizeToRedisEvent.getCountDownLatch().countDown(); //表示初始化完成 log.info("finish InitPrizeToRedisListener," + initPrizeToRedisEvent); } private void setLotteryPrizeToRedis(String key, LotteryPrize lotteryPrize) { redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(Object.class)); redisTemplate.opsForHash().put(key, "id", lotteryPrize.getId()); redisTemplate.opsForHash().put(key, "lotteryId", lotteryPrize.getLotteryId()); redisTemplate.opsForHash().put(key, "prizeName", lotteryPrize.getPrizeName()); redisTemplate.opsForHash().put(key, "prizeType", lotteryPrize.getPrizeType()); redisTemplate.opsForHash().put(key, "totalStock", lotteryPrize.getTotalStock()); redisTemplate.opsForHash().put(key, "validStock", lotteryPrize.getValidStock()); } }
上面部分是通過事件的方法來初始化數據,下面我們說下ApplicationRunner的方式:
這種方式很簡單,在項目啟動的時候將數據加載進去即可。
我們隻需要實現ApplicationRunner接口即可,然後在run方法中從數據庫讀取數據加載到Redis中。
@Slf4j @Component public class LoadDataApplicationRunner implements ApplicationRunner { @Autowired RedisTemplate redisTemplate; @Autowired LotteryMapper lotteryMapper; @Override public void run(ApplicationArguments args) throws Exception { log.info("=========begin load lottery data to Redis==========="); //加載當前抽獎活動信息 Lottery lottery = lotteryMapper.selectById(1); log.info("=========finish load lottery data to Redis==========="); } }
4.6.3 抽獎
我們在使用事件進行數據初始化的時候,可以同時進行抽獎操作,但是註意的是這個時候需要使用countDownLatch.await();來阻塞當前線程,等待數據初始化完成。
在抽獎的過程中,我們首先嘗試從Redis中獲取相關數據,如果Redis中沒有則從數據庫中加載數據,如果數據庫中也沒查詢到相關數據,則表明相關的數據沒有配置完成。
獲取數據之後,我們就該開始抽獎瞭。抽獎的核心在於隨機性以及概率性,咱們總不能隨便抽抽都能抽到一等獎吧?所以我們需要在表中設置每個獎項的概率性。如下所示:
在我們抽獎的時候需要根據概率劃分處相關區間。我們可以通過Debug的方式來查看一下具體怎麼劃分的:
獎項的概率越大,區間越大;大傢看到的順序是不同的,由於我們在上面通過Collections.shuffle(lotteryItems);將集合打亂瞭,所以這裡看到的不是順序展示的。
在生成對應區間後,我們通過生成隨機數,看隨機數落在那個區間中,然後將對應的獎項返回。這就實現瞭我們的抽獎過程。
private LotteryItem doPlay(Lottery lottery) { LotteryItem lotteryItem = null; QueryWrapper<LotteryItem> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("lottery_id", lottery.getId()); Object lotteryItemsObj = redisTemplate.opsForValue().get(RedisKeyManager.getLotteryItemRedisKey(lottery.getId())); List<LotteryItem> lotteryItems; //說明還未加載到緩存中,同步從數據庫加載,並且異步將數據緩存 if (lotteryItemsObj == null) { lotteryItems = lotteryItemMapper.selectList(queryWrapper); } else { lotteryItems = (List<LotteryItem>) lotteryItemsObj; } //獎項數據未配置 if (lotteryItems.isEmpty()) { throw new BizException(ReturnCodeEnum.LOTTER_ITEM_NOT_INITIAL.getCode(), ReturnCodeEnum.LOTTER_ITEM_NOT_INITIAL.getMsg()); } int lastScope = 0; Collections.shuffle(lotteryItems); Map<Integer, int[]> awardItemScope = new HashMap<>(); //item.getPercent=0.05 = 5% for (LotteryItem item : lotteryItems) { int currentScope = lastScope + new BigDecimal(item.getPercent().floatValue()).multiply(new BigDecimal(mulriple)).intValue(); awardItemScope.put(item.getId(), new int[]{lastScope + 1, currentScope}); lastScope = currentScope; } int luckyNumber = new Random().nextInt(mulriple); int luckyPrizeId = 0; if (!awardItemScope.isEmpty()) { Set<Map.Entry<Integer, int[]>> set = awardItemScope.entrySet(); for (Map.Entry<Integer, int[]> entry : set) { if (luckyNumber >= entry.getValue()[0] && luckyNumber <= entry.getValue()[1]) { luckyPrizeId = entry.getKey(); break; } } } for (LotteryItem item : lotteryItems) { if (item.getId().intValue() == luckyPrizeId) { lotteryItem = item; break; } } return lotteryItem; }
4.6.4 調整庫存及記錄
在調整庫存的時候,我們需要考慮到每個獎品類型的不同,根據不同類型的獎品采取不同的措施。比如如果是一些價值高昂的獎品,我們需要通過分佈式鎖來確保安全性;或者比如有些商品我們需要發送相應的短信;所以我們需要采取一種具有擴展性的實現機制。
具體的實現機制可以看下方的類圖,我首先定義一個獎品方法的接口(RewardProcessor),然後定義一個抽象類(AbstractRewardProcessor),抽象類中定義瞭模板方法,然後我們就可以根據不同的類型創建不同的處理器即可,這大大加強瞭我們的擴展性。
比如我們這邊就創建瞭庫存充足處理器及庫存不足處理器。
接口:
public interface RewardProcessor<T> { void doReward(RewardContext context); }
抽象類:
@Slf4j public abstract class AbstractRewardProcessor implements RewardProcessor<RewardContext>, ApplicationContextAware { public static Map<Integer, RewardProcessor> rewardProcessorMap = new ConcurrentHashMap<Integer, RewardProcessor>(); @Autowired protected RedisTemplate redisTemplate; private void beforeProcessor(RewardContext context) { } @Override public void doReward(RewardContext context) { beforeProcessor(context); processor(context); afterProcessor(context); } protected abstract void afterProcessor(RewardContext context); /** * 發放對應的獎品 * * @param context */ protected abstract void processor(RewardContext context); /** * 返回當前獎品類型 * * @return */ protected abstract int getAwardType(); @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { rewardProcessorMap.put(LotteryConstants.PrizeTypeEnum.THANK.getValue(), (RewardProcessor) applicationContext.getBean(NoneStockRewardProcessor.class)); rewardProcessorMap.put(LotteryConstants.PrizeTypeEnum.NORMAL.getValue(), (RewardProcessor) applicationContext.getBean(HasStockRewardProcessor.class)); } }
我們可以從抽象類中的doReward方法處開始查看,比如我們這邊先查看庫存充足處理器中的代碼:
庫存處理器執行的時候首相將Redis中對應的獎項庫存減1,這時候是不需要加鎖的,因為這個操作是原子性的。
當扣減後,我們根據返回的值判斷商品庫存是否充足,這個時候庫存不足則提示未中獎或者返回一個默認商品。
最後我們還需要記得更新下數據庫中的相關數據。
@Override protected void processor(RewardContext context) { //扣減庫存(redis的更新) Long result = redisTemplate.opsForHash().increment(context.getKey(), "validStock", -1); //當前獎品庫存不足,提示未中獎,或者返回一個兜底的獎品 if (result.intValue() < 0) { throw new UnRewardException(ReturnCodeEnum.LOTTER_REPO_NOT_ENOUGHT.getCode(), ReturnCodeEnum.LOTTER_REPO_NOT_ENOUGHT.getMsg()); } List<Object> propertys = Arrays.asList("id", "prizeName"); List<Object> prizes = redisTemplate.opsForHash().multiGet(context.getKey(), propertys); context.setPrizeId(Integer.parseInt(prizes.get(0).toString())); context.setPrizeName(prizes.get(1).toString()); //更新庫存(數據庫的更新) lotteryPrizeMapper.updateValidStock(context.getPrizeId()); }
方法執行完成之後,我們需要執行afterProcessor方法:
這個地方我們是通過異步任務異步存入抽獎記錄信息。
@Override protected void afterProcessor(RewardContext context) { asyncLotteryRecordTask.saveLotteryRecord(context.getAccountIp(), context.getLotteryItem(), context.getPrizeName()); }
在這邊我們可以發現是通過Async註解,指定一個線程池,開啟一個異步執行的方法。
@Slf4j @Component public class AsyncLotteryRecordTask { @Autowired LotteryRecordMapper lotteryRecordMapper; @Async("lotteryServiceExecutor") public void saveLotteryRecord(String accountIp, LotteryItem lotteryItem, String prizeName) { log.info(Thread.currentThread().getName() + "---saveLotteryRecord"); //存儲中獎信息 LotteryRecord record = new LotteryRecord(); record.setAccountIp(accountIp); record.setItemId(lotteryItem.getId()); record.setPrizeName(prizeName); record.setCreateTime(LocalDateTime.now()); lotteryRecordMapper.insert(record); } }
創建一個線程池:相關的配置信息是我們定義在YML文件中的數據。
@Configuration @EnableAsync @EnableConfigurationProperties(ThreadPoolExecutorProperties.class) public class ThreadPoolExecutorConfig { @Bean(name = "lotteryServiceExecutor") public Executor lotteryServiceExecutor(ThreadPoolExecutorProperties poolExecutorProperties) { ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); executor.setCorePoolSize(poolExecutorProperties.getCorePoolSize()); executor.setMaxPoolSize(poolExecutorProperties.getMaxPoolSize()); executor.setQueueCapacity(poolExecutorProperties.getQueueCapacity()); executor.setThreadNamePrefix(poolExecutorProperties.getNamePrefix()); executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy()); return executor; } }
@Data @ConfigurationProperties(prefix = "async.executor.thread") public class ThreadPoolExecutorProperties { private int corePoolSize; private int maxPoolSize; private int queueCapacity; private String namePrefix; }
4.7 總結
以上便是整個項目的搭建,關於前端界面無非就是向後端發起請求,根據返回的獎品信息,將指針落在對應的轉盤位置處,具體代碼可以前往項目地址查看。希望大傢可以動個小手點點贊,嘻嘻。
5. 項目地址
如果直接使用項目的話,記得修改數據庫中活動的結束時間。
Redis
具體的實戰項目在lottery工程中。
到此這篇關於Redis 抽獎大轉盤的實戰示例的文章就介紹到這瞭,更多相關Redis 抽獎大轉盤內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!
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