ElasticSearch查询之聚合查询

一、ES的demo数据如下：

二、简单聚合，获得平均分

GET /student/student/_search
{
  "aggs": {
    "avg_score": {
      "avg": {
        "field": "score"
      }
    }
  }
}

查询结果：

java实现：

/**
 * 聚合查询avg
 *
 *GET /student/student/_search
 * {
 *   "aggs": {
 *     "avg_score": {
 *       "avg": {
 *         "field": "score"
 *       }
 *     }
 *   }
 * }
 *
 */
@ResponseBody
@RequestMapping("/searchAvg")
public Double searchAvg(){
    AvgAggregationBuilder scoreQuery = AggregationBuilders.avg("avg_score");
    scoreQuery.field("score");
    System.out.println(s