领券功能引入分布式锁

引入redisson依赖

pom.xml

@@ -75,7 +75,6 @@
             </dependency>
 
 
-
             <!--mybatis plus和springboot整合-->
             <dependency>
                 <groupId>com.baomidou</groupId>
@@ -93,7 +92,6 @@
             </dependency>
 
 
-
             <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
             <dependency>
                 <groupId>org.apache.commons</groupId>
@@ -110,7 +108,6 @@
             </dependency>
 
 
-
             <!--接口文档依赖-->
             <dependency>
                 <groupId>io.springfox</groupId>
@@ -138,6 +135,13 @@
                 <artifactId>jjwt</artifactId>
                 <version>0.7.0</version>
             </dependency>
+            <!-- 分布式锁 -->
+            <dependency>
+                <groupId>org.redisson</groupId>
+                <artifactId>redisson</artifactId>
+                <version>3.10.1</version>
+            </dependency>
+
 
         </dependencies>
     </dependencyManagement>

xdclass-common/pom.xml

@@ -102,6 +102,12 @@
             <version>0.7.0</version>
         </dependency>
 
+        <!-- redisson -->
+        <dependency>
+            <groupId>org.redisson</groupId>
+            <artifactId>redisson</artifactId>
+        </dependency>
+
     </dependencies>
 
     <properties>

xdclass-common/src/main/java/net/jieyuu/config/AppConfig.java

@@ -0,0 +1,49 @@
+package net.jieyuu.config;
+
+
+import lombok.Data;
+import org.redisson.Redisson;
+import org.redisson.api.RedissonClient;
+import org.redisson.config.Config;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@Data
+public class AppConfig {
+
+    @Value("${spring.redis.host}")
+    private String redisHost;
+
+    @Value("${spring.redis.port}")
+    private String redisPort;
+
+    @Value("${spring.redis.password}")
+    private String redisPwd;
+
+    /**
+     * 配置分布式锁redisson
+     *
+     * @return
+     */
+    @Bean
+    public RedissonClient redissonClient() {
+        Config config = new Config();
+
+        //单机模式
+        config.useSingleServer()
+                .setPassword(redisPwd)
+                .setAddress("redis://" + redisHost + ":" + redisPort);
+
+        //集群模式
+        //config.useClusterServers()
+        //.setScanInterval(2000)
+        //.addNodeAddress("redis://10.0.29.30:6379", "redis://10.0.29.95:6379")
+        //.addNodeAddress("redis://127.0.0.1:6379");
+
+        RedissonClient redisson = Redisson.create(config);
+        return redisson;
+    }
+
+}

xdclass-coupon-service/src/main/java/net/jieyuu/mapper/CouponMapper.java

@@ -2,6 +2,7 @@ package net.jieyuu.mapper;
 
 import net.jieyuu.model.CouponDO;
 import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import org.springframework.data.repository.query.Param;
 
 /**
  * <p>
@@ -15,8 +16,9 @@ public interface CouponMapper extends BaseMapper<CouponDO> {
 
     /**
      * 扣减库存
+     *
      * @param couponId
      * @return
      */
-    int reduceStock(long couponId);
+    int reduceStock(@Param("couponId") long couponId);
 }

xdclass-coupon-service/src/main/java/net/jieyuu/service/impl/CouponServiceImpl.java

@@ -22,11 +22,16 @@ import net.jieyuu.utils.JsonData;
 import net.jieyuu.vo.CouponVO;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.data.redis.core.script.DefaultRedisScript;
 import org.springframework.stereotype.Service;
 
+import java.time.Duration;
+import java.util.Arrays;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
 /**
@@ -47,6 +52,9 @@ public class CouponServiceImpl implements CouponService {
     @Autowired
     private CouponRecordMapper couponRecordMapper;
 
+    @Autowired
+    private StringRedisTemplate redisTemplate;
+
     @Override
     public Map<String, Object> pageCouponActivity(int page, int size) {
         Page<CouponDO> pageInfo = new Page<>(page, size);
@@ -80,6 +88,15 @@ public class CouponServiceImpl implements CouponService {
     public JsonData addCoupon(long couponId, CouponCategoryEnum category) {
         LoginUser loginUser = LoginInterceptor.threadLocal.get();
 
+        String uuid = CommonUtil.generateUUID();
+        String lockKey = "lock:coupon:" + couponId;
+        //避免锁被误删
+        Boolean lockFlag = redisTemplate.opsForValue().setIfAbsent(lockKey, uuid, Duration.ofMinutes(10));
+
+        if (lockFlag) {
+            log.info("加锁成功:{}", couponId);
+            try {
+                // 执行业务逻辑
                 CouponDO couponDO = couponMapper.selectOne(new QueryWrapper<CouponDO>()
                         .eq("id", couponId)
                         .eq("category", category.name()));
@@ -97,8 +114,7 @@ public class CouponServiceImpl implements CouponService {
                 couponRecordDO.setId(null);
 
                 //扣减库存 todo
-        int rows = 1;//couponMapper.reduceStock(couponId);
-
+                int rows = couponMapper.reduceStock(couponId);
                 if (rows == 1) {
                     //扣减库存成功才保存记录
                     couponRecordMapper.insert(couponRecordDO);
@@ -106,7 +122,21 @@ public class CouponServiceImpl implements CouponService {
                     log.warn("发放优惠券错误:{},用户:{}", couponDO, loginUser);
                     throw new BizException(BizCodeEnum.COUPON_NO_STOCK);
                 }
-
+            } finally {
+                // 释放锁
+                // 使用lua脚本保证 查询和删除的原子性
+                String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
+                Integer result = redisTemplate.execute(new DefaultRedisScript<>(script, Integer.class), Arrays.asList(lockKey), uuid);
+                log.info("解锁{}", result);
+            }
+        } else {//加锁失败
+            try {
+                TimeUnit.SECONDS.sleep(1);
+            } catch (InterruptedException e) {
+                log.error("自旋失败");
+            }
+            addCoupon(couponId, category);
+        }
         return JsonData.buildSuccess();
     }
 

xdclass-coupon-service/src/main/resources/mapper/CouponMapper.xml

@@ -24,4 +24,9 @@
         id, category, publish, coupon_img, coupon_title, price, user_limit, start_time, end_time, publish_count, stock, create_time, condition_price
     </sql>
 
+    <!--扣减库存-->
+    <update id="reduceStock">
+        update coupon set stock=stock-1 where id = #{couponId} and stock > 0
+    </update>
+
 </mapper>