Elasticsearch聚合出商品的一级分类与二级分类组装成树型结构返回

项目中要对es中的商品聚合出 前端一级分类与二级分类，并且对一二级分类按设置的排序值进行排序后返回树型结构；

项目中一个商品可以对应多个前台分类 ， 所以es索引中前台分类用Nested类型存储，_mapping结构如下：

 

 

 存储数据时对 一二三级分类数据的相关字段拼接成 id|name|parentId|sort|level|icon  这样的字符串；

 

 java代码如下：

代码中：EsProductFields.frontFirstCategoryInfo="frontCategoryList.frontFirstCategoryInfo.keyword"

              EsProductFields.frontSecondCategoryInfo="frontCategoryList.frontSecondCategoryInfo.keyword"

 

       @Autowired
       private ElasticsearchRestTemplate es;

 

public List<ESCategoryDTO> selectCategoryList(SearchParameter param) {
    if (param.getBuyerDistrictId() == null && Objects.nonNull(param.getBuyerId())) {
        if (ObjectUtil.equal(param.getRequestSource(), SearchRequestSourceEnum.JDE_CHANNEL_PURCHASE.getCode())) {
            param.setBuyerDistrictId(null);
        } else {
            Long buyerDistrictId = remoteSellerClient.getBuyerAreaId(param.getBuyerId()).getData();
            param.setBuyerDistrictId(buyerDistrictId);
        }
    }
    NativeSearchQueryBuilder queryBuilder = getSearchQuery(param);
    //聚合一级分类
    TermsAggregationBuilder firstTermsAgg = AggregationBuilders.terms("firstAgg").field(EsProductFields.frontFirstCategoryInfo);
    firstTermsAgg.size(200);
    FilterAggregationBuilder filterAgg1 = new FilterAggregationBuilder("filterAgg", getFilter(param));
    filterAgg1.subAggregation(firstTermsAgg);
    //聚合二级分类
    TermsAggregationBuilder secondTermsAgg = AggregationBuilders.terms("secondAgg").field(EsProductFields.frontSecondCategoryInfo);
    secondTermsAgg.size(10000);
    filterAgg1.subAggregation(secondTermsAgg);
    queryBuilder.addAggregation(filterAgg1);
    List<String> list = new ArrayList<>();
    SearchHits<EsProductDTO> search = es.search(queryBuilder.build(), EsProductDTO.class);
    if (search.hasSearchHits()) {
        for (Aggregation item : search.getAggregations()) {
            JSONObject jsonObject = JSONUtil.parseObj(item);
            JSONArray subAggregations = jsonObject.getJSONArray("aggregations");
            for (Object subAggregation : subAggregations) {
                JSONObject subAggJsonObject = JSONUtil.parseObj(subAggregation);
                JSONArray buckets = subAggJsonObject.getJSONArray("buckets");
                for (Object bucket : buckets) {
                    JSONObject model = JSONUtil.parseObj(bucket);
                    list.add(model.get("key").toString());
                }
            }
        }
    }
    List<ESCategoryDTO> categoryList = new ArrayList<>();
    if (CollUtil.isNotEmpty(list)) {
        for (String item : list) {
            //id|name|parentId|sort|level|icon   分类信息按竖线分割
            String[] categoryArr = item.split("\\|");
            ESCategoryDTO model = new ESCategoryDTO();
            model.setId(categoryArr[0]);
            model.setName(categoryArr[1]);
            model.setParentId(Long.parseLong(categoryArr[2]));
            model.setSort(Integer.parseInt(categoryArr[3]));
            model.setLevel(Integer.parseInt(categoryArr[4]));
            model.setIcon(categoryArr[5].equals("null") ? "" : categoryArr[5]);
            model.setCategoryType(CategoryTypeEnum.CATEGORY.getCode());
            categoryList.add(model);
        }
    }
    if (CollUtil.isNotEmpty(categoryList)) {
        //组装成树型结构
        List<ESCategoryDTO> firstCategoryList = categoryList.stream().filter(c -> c.getLevel().equals(CategoryLevel.FIRST)).collect(Collectors.toList());
        //一级分类按sort排序
        firstCategoryList.sort(Comparator.comparing(ESCategoryDTO::getSort).reversed());
        for (ESCategoryDTO item : firstCategoryList) {
            List<ESCategoryDTO> secondCategoryList = categoryList.stream().filter(c -> c.getParentId().equals(Long.parseLong(item.getId()))).collect(Collectors.toList());
            //二级分类按sort排序
            secondCategoryList.sort(Comparator.comparing(ESCategoryDTO::getSort).reversed());
            item.setChildCategoryList(secondCategoryList);
        }
        return firstCategoryList;
    }
    return new ArrayList<>();
}