elsaticSerachTemplate的api_searchhits.getaggregations()

QueryBuilders提供了大量的静态方法，用于生成各种不同类型的查询对象，例如：词条、模糊、通配符等QueryBuilder对象。

NativeSearchQueryBuilder：Spring提供的一个查询条件构建器，帮助构建json格式的请求体

  public List<Article> getByContentNative(String content) {
        MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("content", content);
        NativeSearchQueryBuilder queryBuilder = new NativeSearchQueryBuilder();
        queryBuilder.withQuery(matchQueryBuilder);
        SearchHits<Article> searchHits = elasticsearchRestTemplate.search(queryBuilder.build(), Article.class);
        return searchHits.get().map(SearchHit::getContent).collect(Collectors.toList());
    }

聚合取数据

addAggretion方法

  /**
     * 根据type聚合
     */
    public void getCountByTypes() {
        NativeSearchQueryBuilder nativeSearchQueryBuilder = new NativeSearchQueryBuilder();
        // 设置要查询的字段
        nativeSearchQueryBuilder.withSourceFilter(new FetchSourceFilter(new String[]{""}, null));
        // 设置一下查询的条数
        nativeSearchQueryBuilder.withPageable(PageRequest.of(0, 1));
        // 设置聚合字段，指定聚合后的字段名，以及根据哪个字段聚合
        nativeSearchQueryBuilder.addAggregation(AggregationBuilders.terms("typeCount").field("types"));
        // 搜索
        SearchHits<Article> searchHits = elasticsearchRestTemplate.search(nativeSearchQueryBuilder.build(), Article.class);
        // 取出来聚合的数据
        Aggregations aggregations = searchHits.getAggregations();
        // 取出我们聚合的字段
        Terms terms = aggregations.get("typeCount");
        List<? extends Terms.Bucket> buckets = terms.getBuckets();
        for (Terms.Bucket bucket : buckets) {
            System.out.println(bucket.getKey());
            System.out.println(bucket.getDocCount());
        }
 
    }