Elasticsearch(es)根据某个字段聚合分组，然后每组中取一个

Elasticsearch(es)根据某个字段聚合分组，然后每组中取一个

 

    @Autowired
    JestClient jestClient;

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  SearchResult searchResult = jestClient.execute(search);

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        // 聚合分组
        TermsAggregationBuilder groupby_attr = AggregationBuilders.terms("field_Agg").field("field");

        // 仅显示每一组中第一个document
        TopHitsAggregationBuilder suBuilder = AggregationBuilders.topHits("sub_agg").size(1);
        groupby_attr.subAggregation(suBuilder);

        searchSourceBuilder.aggregation(groupby_attr);

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            //按照专辑id对搜索结果进行分组，并且从每组中取出一个
            JsonArray listt = searchResult.getAggregations().getTopHitsAggregation("field_Agg").getJsonObject()
                    .getAsJsonArray("buckets");

            List vvList = new ArrayList();

            for (JsonElement jsonElement : listt) {

                JsonObject ss = jsonElement.getAsJsonObject().getAsJsonObject("sub_agg").getAsJsonObject("hits")
                        .getAsJsonArray("hits").get(0).getAsJsonObject().getAsJsonObject("_source");
                ESDO vv = new Gson().fromJson(ss, Bean.class);
                vvList.add(vv);
            }

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FR：徐海涛（hunk xu）
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