ElasticSearch執行多個字段Sum操作，但不進行分組Group操作

本文僅適合java、es都是小白的同志一起學習，大拿的就請直接路過吧。

之前一直使用NET開發項目，採用ElasticSearch+MongoDB模式進行數據存儲，索引。20年單位要求在Java平臺上開發，原有的系統，需要用java定製，開始摸着石頭過河，來寫Java操作Es、MongoDB。

運行環境單位部署的ES爲5.6.16

客戶端對應：

elasticsearch    5.6.16

elasticsearch-rest-high-level-client  5.6.16

elasticsearch-rest-client  5.6.16

記錄第一篇ES統計多個Sum函數，不進行分組(group by)。（對於小白來說，試驗了好久才整出來，主要還是Java語言應用不熟悉吧）

searchSourceBuilder.aggregation(hitagg).aggregation(revertagg); //注意這個多個aggregation

直接上例子：

 /**
     * 統計點擊量、回覆量和sum值
     * @param ec es連接對象
     * @param mtj 統計條件
     * @return
     * @throws IOException
     */
    public static Map<String,Long> FacetHitAndRevertToSum(EsConnect ec, MainInfoJStj mtj) throws Exception {

        //定義返回對象
        Map<String,Long> reslut = new HashMap<String,Long>();

        //定義連接對象
        RestHighLevelClient client = RestHighLevelClientBuild.getHighLevelClient(ec.EsIpAddress,ec.EsPort);

        //換行檢索條件
        BoolQueryBuilder query = SearchMainInfo.combinationSearchMaininfo(mtj);

        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices(ec.EsIndex); //指定索引
        searchRequest.types(ec.EsType); //指定type
        searchRequest.searchType(SearchType.DEFAULT);

        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.size(1);
        searchSourceBuilder.query(query);
        searchSourceBuilder.from(0);

        //類似：select sum(hit),sum(revert) from table

        //定義求和hit
        SumAggregationBuilder hitagg = AggregationBuilders.sum("by_hit").field("hit");

        //定義求和revert
        SumAggregationBuilder revertagg = AggregationBuilders.sum("by_revert").field("revert");

        //注意多個aggregation
        searchSourceBuilder.aggregation(hitagg).aggregation(revertagg);

        searchRequest.source(searchSourceBuilder);

        SearchResponse searchResponse = client.search(searchRequest);

        Sum by_hit = searchResponse.getAggregations().get("by_hit");
        Sum by_revert = searchResponse.getAggregations().get("by_revert");
        //點擊量和
        double hitsum = by_hit.getValue();
        //回覆量和
        double revertsum = by_revert.getValue();

        reslut.put("hit",(long)hitsum);
        reslut.put("revert",(long)revertsum);

        return reslut;

    }