抽奖完善

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

@@ -122,7 +122,7 @@ public class SweetIntegralActivityDrawServiceImpl extends ServiceImpl<SweetInteg
                 if (CollectionUtils.isEmpty(activityPrizeVoArrayList)) {
                     return ResponseDto.failure("活动太火爆了，奖品已经没有库存啦～");
                 }
-                IntegralActivityPrizeVo integralActivityPrizeVo = this.lotteryDraw(activityPrizeVoArrayList);
+                IntegralActivityPrizeVo integralActivityPrizeVo = this.lotteryDraw1(activityPrizeVoArrayList);
 
                 // 减库存 顺便判断库存是否够 -1的时候回滚回去
                 long activityPrizeNum = redisDataUtils.decrIntegralActivityPrizeNum(integralActivityId, integralActivityPrizeVo.getPrizeId(), 1);
@@ -323,9 +323,45 @@ public class SweetIntegralActivityDrawServiceImpl extends ServiceImpl<SweetInteg
     }
 
     /**
-     * 抽奖方法
+     * 抽奖方法 积分、券
      */
-    private static IntegralActivityPrizeVo lotteryDraw(List<IntegralActivityPrizeVo> prizeList) {
+    private static IntegralActivityPrizeVo lotteryDraw1(List<IntegralActivityPrizeVo> prizeList) {
+        if (prizeList == null || prizeList.isEmpty()) {
+            return null;
+        }
+
+        int size = prizeList.size();
+
+        // 计算总概率，这样可以保证不一定总概率是1
+        BigDecimal sumRate = BigDecimal.ZERO;
+        for (IntegralActivityPrizeVo prize : prizeList) {
+            sumRate = sumRate.add(prize.getWinningProbability());
+        }
+
+        // 计算每个物品在总概率的基础下的概率情况
+        List<BigDecimal> sortOrignalRates = new ArrayList<>(size);
+        BigDecimal tempSumRate = BigDecimal.ZERO;
+        for (IntegralActivityPrizeVo prize : prizeList) {
+            tempSumRate = tempSumRate.add(prize.getWinningProbability());
+            sortOrignalRates.add(tempSumRate.divide(sumRate, 4, BigDecimal.ROUND_HALF_UP));
+        }
+
+        // 根据区块值来获取抽取到的物品索引
+        double nextDouble = Math.random();
+        BigDecimal nextDoubleNew = BigDecimal.valueOf(nextDouble);
+        sortOrignalRates.add(nextDoubleNew);
+        Collections.sort(sortOrignalRates);
+
+        int index = sortOrignalRates.indexOf(nextDoubleNew);
+
+        IntegralActivityPrizeVo integralActivityPrizeVo = prizeList.get(index);
+        return integralActivityPrizeVo;
+    }
+
+    /**
+     * 抽奖方法 实物、会员
+     */
+    private static IntegralActivityPrizeVo lotteryDraw2(List<IntegralActivityPrizeVo> prizeList) {
         if (prizeList == null || prizeList.isEmpty()) {
             return null;
         }