mongodb的聚合查询,里面包含枚举类型的查询时, 要转成String再做查询,否则会报:

org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class  ...

记录一下.

例如下例中的SearchLogType.USER.toString()

try {      Criteria rightIntervalCR = Criteria.where("time").lt(rightIntervalDate);      Criteria leftIntervalCR = Criteria.where("time").gte(leftIntervalDate);      Criteria onlineCR = Criteria.where("type").is(SearchLogType.USER.toString());//只查询线上问的日志      String[] groupUseFields = {"userid"};      AggregationOperation matchOperation = new MatchOperation(leftIntervalCR.andOperator(onlineCR, rightIntervalCR));      AggregationOperation groupOperation = new GroupOperation(Fields.fields(groupUseFields));      AggregationOperation[] aggregationOperations = new AggregationOperation[2];      aggregationOperations[0] = matchOperation;      aggregationOperations[1] = groupOperation;      Aggregation aggregation = Aggregation.newAggregation(aggregationOperations);      AggregationResults
    
      aggregationResults = mongoOperation.aggregate(aggregation, logCollectionName, String.class);      List
     
       useridList = aggregationResults.getMappedResults();      if (useridList != null) {        for (String userid : useridList) {          JsonObject useridJsonObject = GsonFactory.getGsonClient().fromJson((String) userid, JsonObject.class);          String useridStr = useridJsonObject.get("_id").getAsString();         }      }    } catch (Exception e) {      e.printStackTrace();    }