Redis?抽獎(jiǎng)大轉(zhuǎn)盤的實(shí)戰(zhàn)示例

更新時(shí)間：2021年12月31日 09:09:44 作者：、楽.

本文主要介紹了Redis?抽獎(jiǎng)大轉(zhuǎn)盤的實(shí)戰(zhàn)示例，文中通過(guò)示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

1. 項(xiàng)目介紹

這是一個(gè)基于Spring boot + Mybatis Plus + Redis 的簡(jiǎn)單案例。

主要是將活動(dòng)內(nèi)容、獎(jiǎng)品信息、記錄信息等緩存到Redis中，然后所有的抽獎(jiǎng)過(guò)程全部從Redis中做數(shù)據(jù)的操作。

大致內(nèi)容很簡(jiǎn)單，具體操作下面慢慢分析。

2. 項(xiàng)目演示

話不多說(shuō)，首先上圖看看項(xiàng)目效果，如果覺(jué)得還行的話咱們就來(lái)看看他具體是怎么實(shí)現(xiàn)的。

3. 表結(jié)構(gòu)

該項(xiàng)目包含以下四張表，分別是活動(dòng)表、獎(jiǎng)項(xiàng)表、獎(jiǎng)品表以及中獎(jiǎng)記錄表。具體的SQL會(huì)在文末給出。

4. 項(xiàng)目搭建

咱們首先先搭建一個(gè)標(biāo)準(zhǔn)的Spring boot 項(xiàng)目，直接IDEA創(chuàng)建，然后選擇一些相關(guān)的依賴即可。

4.1 依賴

該項(xiàng)目主要用到了：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

依賴引入之后，我們需要進(jìn)行相應(yīng)的配置：數(shù)據(jù)庫(kù)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(chǔ)的業(yè)務(wù)代碼，避免這些重復(fù)的體力活。

這邊貼出相關(guān)代碼，直接修改數(shù)據(jù)庫(kù)連接信息、相關(guān)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(shí)體屬性 Swagger2 注解
        gc.setSwagger2(false);
        mpg.setGlobalConfig(gc);

        // 數(shù)據(jù)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");
        // 寫于父類中的公共字段
//        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(qǐng)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(qǐng)輸入正確的" + tip + "！");
    }
}

4.4 Redis 配置

我們?nèi)绻诖a中使用 RedisTemplate 的話，需要添加相關(guān)配置，將其注入到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(rèn)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(shè)置value的序列化規(guī)則和 key的序列化規(guī)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

由于代碼中會(huì)用到一些共有的常量，我們應(yīng)該將其抽離出來(lái)。

public class LotteryConstants {

    /**
     * 表示正在抽獎(jiǎng)的用戶標(biāo)記
     */
    public final static String DRAWING = "DRAWING";
    
    /**
     * 活動(dòng)標(biāo)記 LOTTERY:lotteryID
     */
    public final static String LOTTERY = "LOTTERY";
    
    /**
     * 獎(jiǎng)品數(shù)據(jù)  LOTTERY_PRIZE:lotteryID:PrizeId
     */
    public final static String LOTTERY_PRIZE = "LOTTERY_PRIZE";
    
    /**
     * 默認(rèn)獎(jiǎng)品數(shù)據(jù)  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(jiǎng)項(xiàng)緩存：LOTTERY_ITEM:LOTTERY_ID
     */
    public final static String LOTTERY_ITEM = "LOTTERY_ITEM";
    
    /**
     * 默認(rèn)獎(jiǎng)項(xiàng)： 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(jiǎng)活動(dòng)不存在"),

    LOTTER_FINISH("9002", "活動(dòng)已結(jié)束"),

    LOTTER_REPO_NOT_ENOUGHT("9003", "當(dāng)前獎(jiǎng)品庫(kù)存不足"),

    LOTTER_ITEM_NOT_INITIAL("9004", "獎(jiǎng)項(xiàng)數(shù)據(jù)未初始化"),

    LOTTER_DRAWING("9005", "上一次抽獎(jiǎng)還未結(jié)束"),

    REQUEST_PARAM_NOT_VALID("9998", "請(qǐng)求參數(shù)不正確"),

    SYSTEM_ERROR("9999", "系統(tǒng)繁忙,請(qǐng)稍后重試");

    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(duì)Redis中的key進(jìn)行統(tǒng)一的管理。

public class RedisKeyManager {

    /**
     * 正在抽獎(jiǎng)的key
     *
     * @param accountIp
     * @return
     */
    public static String getDrawingRedisKey(String accountIp) {
        return new StringBuilder(LotteryConstants.DRAWING).append(":").append(accountIp).toString();
    }

    /**
     * 獲取抽獎(jiǎng)活動(dòng)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(dòng)下的所有獎(jiǎng)品數(shù)據(jù)
     *
     * @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(yè)務(wù)代碼

4.6.1 抽獎(jiǎng)接口

我們首先編寫抽獎(jiǎng)接口，根據(jù)前臺(tái)傳的參數(shù)查詢到具體的活動(dòng)，然后進(jìn)行相應(yīng)的操作。（當(dāng)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(dāng)前用戶上一次抽獎(jiǎng)是否結(jié)束
        checkDrawParams(id, accountIp);

        //抽獎(jiǎng)
        DoDrawDto dto = new DoDrawDto();
        dto.setAccountIp(accountIp);
        dto.setLotteryId(id);
        lotteryService.doDraw(dto);

        //返回結(jié)果設(shè)置
        resultResp.setCode(ReturnCodeEnum.SUCCESS.getCode());
        resultResp.setMsg(ReturnCodeEnum.SUCCESS.getMsg());
        //對(duì)象轉(zhuǎn)換
        resultResp.setResult(lotteryConverter.dto2LotteryItemVo(dto));
    } catch (Exception e) {
        return ExceptionUtil.handlerException4biz(resultResp, e);
    } finally {
        //清除占位標(biāo)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(dāng)前用戶上一次抽獎(jiǎng)是否結(jié)束
    Boolean result = redisTemplate.opsForValue().setIfAbsent(RedisKeyManager.getDrawingRedisKey(accountIp), "1", 60, TimeUnit.SECONDS);
    //如果為false，說(shuō)明上一次抽獎(jiǎng)還未結(jié)束
    if (!result) {
        throw new RewardException(ReturnCodeEnum.LOTTER_DRAWING.getCode(), ReturnCodeEnum.LOTTER_DRAWING.getMsg());
    }
}

為了避免用戶重復(fù)點(diǎn)擊抽獎(jiǎng)，所以我們通過(guò)Redis來(lái)避免這種問(wèn)題，用戶每次抽獎(jiǎng)的時(shí)候，通過(guò)setNx給用戶排隊(duì)并設(shè)置過(guò)期時(shí)間；如果用戶點(diǎn)擊多次抽獎(jiǎng)，Redis設(shè)置值的時(shí)候發(fā)現(xiàn)該用戶上次抽獎(jiǎng)還未結(jié)束則拋出異常。

最后用戶抽獎(jiǎng)成功的話，記得清除該標(biāo)記，從而用戶能夠繼續(xù)抽獎(jiǎng)。

4.6.2 初始化數(shù)據(jù)

從抽獎(jiǎng)入口進(jìn)來(lái)，校驗(yàn)成功以后則開(kāi)始業(yè)務(wù)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(jié)束之后才能運(yùn)行
        CountDownLatch countDownLatch = new CountDownLatch(1);
        //判斷活動(dòng)有效性
        Lottery lottery = checkLottery(drawDto);
        //發(fā)布事件，用來(lái)加載指定活動(dòng)的獎(jiǎng)品信息
        applicationContext.publishEvent(new InitPrizeToRedisEvent(this, lottery.getId(), countDownLatch));
        //開(kāi)始抽獎(jiǎng)
        lotteryItem = doPlay(lottery);
        //記錄獎(jiǎng)品并扣減庫(kù)存
        countDownLatch.await(); //等待獎(jiǎng)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(diào)整庫(kù)存及記錄中獎(jiǎng)信息
        AbstractRewardProcessor.rewardProcessorMap.get(prizeType).doReward(context);
    } catch (UnRewardException u) { //表示因?yàn)槟承﹩?wèn)題未中獎(jiǎng)，返回一個(gè)默認(rèn)獎(jiǎng)項(xiàng)
        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?cái)?shù)據(jù)
    drawDto.setLevel(lotteryItem.getLevel());
    drawDto.setPrizeName(context.getPrizeName());
    drawDto.setPrizeId(context.getPrizeId());
}

首先我們通過(guò)CountDownLatch來(lái)保證商品初始化的順序，關(guān)于CountDownLatch可以查看 JUC工具該文章。

然后我們需要檢驗(yàn)一下活動(dòng)的有效性，確保活動(dòng)未結(jié)束。

檢驗(yàn)活動(dòng)通過(guò)后則通過(guò)ApplicationEvent 事件實(shí)現(xiàn)獎(jiǎng)品數(shù)據(jù)的加載，將其存入Redis中。或者通過(guò)ApplicationRunner在程序啟動(dòng)時(shí)獲取相關(guān)數(shù)據(jù)。我們這使用的是事件機(jī)制。ApplicationRunner 的相關(guān)代碼在下文我也順便貼出。

事件機(jī)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;
    }
}

有了事件機(jī)制，我們還需要一個(gè)監(jiān)聽(tīng)事件，用來(lái)初始化相關(guān)數(shù)據(jù)信息。具體業(yè)務(wù)邏輯大家可以參考下代碼，有相關(guān)的注釋信息，主要就是將數(shù)據(jù)庫(kù)中的數(shù)據(jù)添加進(jìn)redis中，需要注意的是，我們?yōu)榱吮ＷC原子性，是通過(guò)HASH來(lái)存儲(chǔ)數(shù)據(jù)的，這樣之后庫(kù)存扣減的時(shí)候就可以通過(guò)opsForHash來(lái)保證其原子性。

當(dāng)初始化獎(jiǎng)品信息之后，則通過(guò)countDown()方法表名執(zhí)行完成，業(yè)務(wù)代碼中線程阻塞的地方可以繼續(xù)執(zhí)行了。

@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(jīng)初始化到緩存中了，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(jiǎng)品沒(méi)有了，會(huì)生成一個(gè)默認(rèn)的獎(jiǎng)項(xiàng)
        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(gè)默認(rèn)獎(jiǎng)項(xiàng)
        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(guò)事件的方法來(lái)初始化數(shù)據(jù)，下面我們說(shuō)下ApplicationRunner的方式：

這種方式很簡(jiǎn)單，在項(xiàng)目啟動(dòng)的時(shí)候?qū)?shù)據(jù)加載進(jìn)去即可。

我們只需要實(shí)現(xiàn)ApplicationRunner接口即可，然后在run方法中從數(shù)據(jù)庫(kù)讀取數(shù)據(jù)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(dāng)前抽獎(jiǎng)活動(dòng)信息
        Lottery lottery = lotteryMapper.selectById(1);

        log.info("=========finish load lottery data to Redis===========");
    }
}

4.6.3 抽獎(jiǎng)

我們?cè)谑褂檬录M(jìn)行數(shù)據(jù)初始化的時(shí)候，可以同時(shí)進(jìn)行抽獎(jiǎng)操作，但是注意的是這個(gè)時(shí)候需要使用countDownLatch.await();來(lái)阻塞當(dāng)前線程，等待數(shù)據(jù)初始化完成。

在抽獎(jiǎng)的過(guò)程中，我們首先嘗試從Redis中獲取相關(guān)數(shù)據(jù)，如果Redis中沒(méi)有則從數(shù)據(jù)庫(kù)中加載數(shù)據(jù)，如果數(shù)據(jù)庫(kù)中也沒(méi)查詢到相關(guān)數(shù)據(jù)，則表明相關(guān)的數(shù)據(jù)沒(méi)有配置完成。

獲取數(shù)據(jù)之后，我們就該開(kāi)始抽獎(jiǎng)了。抽獎(jiǎng)的核心在于隨機(jī)性以及概率性，咱們總不能隨便抽抽都能抽到一等獎(jiǎng)吧？所以我們需要在表中設(shè)置每個(gè)獎(jiǎng)項(xiàng)的概率性。如下所示：

在我們抽獎(jiǎng)的時(shí)候需要根據(jù)概率劃分處相關(guān)區(qū)間。我們可以通過(guò)Debug的方式來(lái)查看一下具體怎么劃分的：

獎(jiǎng)項(xiàng)的概率越大，區(qū)間越大；大家看到的順序是不同的，由于我們?cè)谏厦嫱ㄟ^(guò)Collections.shuffle(lotteryItems);將集合打亂了，所以這里看到的不是順序展示的。

在生成對(duì)應(yīng)區(qū)間后，我們通過(guò)生成隨機(jī)數(shù)，看隨機(jī)數(shù)落在那個(gè)區(qū)間中，然后將對(duì)應(yīng)的獎(jiǎng)項(xiàng)返回。這就實(shí)現(xiàn)了我們的抽獎(jiǎng)過(guò)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(shuō)明還未加載到緩存中，同步從數(shù)據(jù)庫(kù)加載，并且異步將數(shù)據(jù)緩存
    if (lotteryItemsObj == null) {
        lotteryItems = lotteryItemMapper.selectList(queryWrapper);
    } else {
        lotteryItems = (List<LotteryItem>) lotteryItemsObj;
    }
    //獎(jiǎng)項(xiàng)數(shù)據(jù)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(diào)整庫(kù)存及記錄

在調(diào)整庫(kù)存的時(shí)候，我們需要考慮到每個(gè)獎(jiǎng)品類型的不同，根據(jù)不同類型的獎(jiǎng)品采取不同的措施。比如如果是一些價(jià)值高昂的獎(jiǎng)品，我們需要通過(guò)分布式鎖來(lái)確保安全性；或者比如有些商品我們需要發(fā)送相應(yīng)的短信；所以我們需要采取一種具有擴(kuò)展性的實(shí)現(xiàn)機(jī)制。

具體的實(shí)現(xiàn)機(jī)制可以看下方的類圖，我首先定義一個(gè)獎(jiǎng)品方法的接口（RewardProcessor），然后定義一個(gè)抽象類（AbstractRewardProcessor），抽象類中定義了模板方法，然后我們就可以根據(jù)不同的類型創(chuàng)建不同的處理器即可，這大大加強(qiáng)了我們的擴(kuò)展性。

比如我們這邊就創(chuàng)建了庫(kù)存充足處理器及庫(kù)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(fā)放對(duì)應(yīng)的獎(jiǎng)品
     *
     * @param context
     */
    protected abstract void processor(RewardContext context);

    /**
     * 返回當(dāng)前獎(jiǎng)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(kāi)始查看，比如我們這邊先查看庫(kù)存充足處理器中的代碼：

庫(kù)存處理器執(zhí)行的時(shí)候首相將Redis中對(duì)應(yīng)的獎(jiǎng)項(xiàng)庫(kù)存減1，這時(shí)候是不需要加鎖的，因?yàn)檫@個(gè)操作是原子性的。

當(dāng)扣減后，我們根據(jù)返回的值判斷商品庫(kù)存是否充足，這個(gè)時(shí)候庫(kù)存不足則提示未中獎(jiǎng)或者返回一個(gè)默認(rèn)商品。

最后我們還需要記得更新下數(shù)據(jù)庫(kù)中的相關(guān)數(shù)據(jù)。

@Override
protected void processor(RewardContext context) {
    //扣減庫(kù)存（redis的更新）
    Long result = redisTemplate.opsForHash().increment(context.getKey(), "validStock", -1);
    //當(dāng)前獎(jiǎng)品庫(kù)存不足，提示未中獎(jiǎng)，或者返回一個(gè)兜底的獎(jiǎng)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(kù)存（數(shù)據(jù)庫(kù)的更新）
    lotteryPrizeMapper.updateValidStock(context.getPrizeId());
}

方法執(zhí)行完成之后，我們需要執(zhí)行afterProcessor方法：

這個(gè)地方我們是通過(guò)異步任務(wù)異步存入抽獎(jiǎng)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(fā)現(xiàn)是通過(guò)Async注解，指定一個(gè)線程池，開(kāi)啟一個(gè)異步執(zhí)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(chǔ)中獎(jiǎng)信息
        LotteryRecord record = new LotteryRecord();
        record.setAccountIp(accountIp);
        record.setItemId(lotteryItem.getId());
        record.setPrizeName(prizeName);
        record.setCreateTime(LocalDateTime.now());
        lotteryRecordMapper.insert(record);
    }
}

創(chuàng)建一個(gè)線程池：相關(guān)的配置信息是我們定義在YML文件中的數(shù)據(jù)。

@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(jié)

以上便是整個(gè)項(xiàng)目的搭建，關(guān)于前端界面無(wú)非就是向后端發(fā)起請(qǐng)求，根據(jù)返回的獎(jiǎng)品信息，將指針落在對(duì)應(yīng)的轉(zhuǎn)盤位置處，具體代碼可以前往項(xiàng)目地址查看。希望大家可以動(dòng)個(gè)小手點(diǎn)點(diǎn)贊，嘻嘻。

5. 項(xiàng)目地址

如果直接使用項(xiàng)目的話，記得修改數(shù)據(jù)庫(kù)中活動(dòng)的結(jié)束時(shí)間。

Redis

具體的實(shí)戰(zhàn)項(xiàng)目在lottery工程中。

到此這篇關(guān)于Redis 抽獎(jiǎng)大轉(zhuǎn)盤的實(shí)戰(zhàn)示例的文章就介紹到這了,更多相關(guān)Redis 抽獎(jiǎng)大轉(zhuǎn)盤內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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