随机数算法

liquidnet-bus-service/liquidnet-service-sweet/src/main/java/com/liquidnet/service/sweet/service/impl/SweetIntegralActivityDrawServiceImpl.java

@@ -444,7 +444,7 @@ public class SweetIntegralActivityDrawServiceImpl extends ServiceImpl<SweetInteg
     /**
      * 抽奖方法 计算中哪个奖池的奖品
      */
-    private boolean lotteryDraw(String integralActivityId, String uid) {
+    /*private boolean lotteryDraw(String integralActivityId, String uid) {
         // 随机数
         double random = Math.random() * 100;
         BigDecimal randomBig = BigDecimal.valueOf(random);
@@ -474,6 +474,40 @@ public class SweetIntegralActivityDrawServiceImpl extends ServiceImpl<SweetInteg
         } else {
             return false;
         }
+    }*/
+    /**
+     * 抽奖方法 计算中哪个奖池的奖品
+     */
+    private boolean lotteryDraw(String integralActivityId, String uid) {
+        int estimatedNum = redisDataUtils.getIntegralActivityEstimatedNum(integralActivityId);
+        if (estimatedNum <= 0) { // 此时百分百中实物
+            return true;
+        }
+        // 剩余总库存 添加编辑的时候冗余的总库存省去计算
+        int prizeNum = redisDataUtils.getIntegralActivityTotalPrizeNum(integralActivityId);
+        BigDecimal prizeNumBig = BigDecimal.valueOf(prizeNum);
+        // 概率
+        BigDecimal estimatedNumBig = BigDecimal.valueOf(estimatedNum);
+        // 会员概率*2
+        try {
+            ResponseDto<Boolean> isMemberDto = feignAdamBaseClient.isMember(uid);
+            Boolean isMember = isMemberDto.getData();
+            if (isMember) {
+                estimatedNumBig = estimatedNumBig.divide(BigDecimal.valueOf(2), 2, BigDecimal.ROUND_HALF_UP);
+            }
+        } catch (Exception e) {
+            log.error("获取用户是否是会员失败 [uid:{}, e:{}]", uid, e);
+        }
+        // 随机数
+        double random = Math.random();
+        BigDecimal randomBig = BigDecimal.valueOf(random);
+        BigDecimal randomBigNew = randomBig.multiply(estimatedNumBig);
+        // 对比大小
+        if (randomBigNew.compareTo(prizeNumBig) <= 0) {
+            return true; // 0 - 剩余预估人数的随机数 <= 实物剩余总库存 中实物
+        } else {
+            return false;
+        }
     }
 
     /*public static void main(String[] args) {