Restclient multi conditional aggregation

In the corresponding service Write in layer ：

 HotelService The code in is as follows ：

@Override
    public Map<String, List<String>> filters()  {

        try {
            //1.  Get ready Request
            SearchRequest request = new SearchRequest("hotel");
            //2.  Get ready DSL
            //2.1  Set up size
            request.source().size(0);
            //2.2  polymerization 
            buildAggretgaion(request);

            //3.  Request 
            SearchResponse response = client.search(request,RequestOptions.DEFAULT);

            //4.  Analysis results 
            Map<String,List<String>> result = new HashMap<String, List<String>>();
            Aggregations aggregations = response.getAggregations();
            //4.1  According to brand （ Aggregate name ） Name gets the result of the brand 
            List<String> brandList = getAddByName(aggregations,"brandAgg");
            result.put(" brand ",brandList); // Put in map
            //4.2  According to the city （ Aggregate name ） Name gets the result of the brand 
            List<String> cityList = getAddByName(aggregations,"cityList");
            result.put(" City ",cityList); // Put in map
            //4.3  According to stars （ Aggregate name ） Name gets the result of the brand 
            List<String> starList = getAddByName(aggregations,"starList");
            result.put(" The star ",starList); // Put in map

            return result;

        } catch (IOException e) {
            throw new RuntimeException();
        }
    }

    //( Extracted from )  Get the results of the brand according to the name 
    private List<String> getAddByName(Aggregations aggregations, String aggName) {
        //4.1  Get the aggregation result according to the aggregation name 
        Terms brandTerms = aggregations.get(aggName);
        //4.2  obtain buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
        //4.3  Traverse 
        List<String> brandList = new ArrayList<String>();
        for(Terms.Bucket bucket : buckets){
            //4.4  obtain key
            String key = bucket.getKeyAsString();
            brandList.add(key);

            System.out.println(key);
        }
        return brandList;
    }

    // Extracted from   polymerization 
    private void buildAggretgaion(SearchRequest request) {
        request.source().aggregation(AggregationBuilders
                .terms("brandAgg")
                .field("brand")
                .size(10)
        );
        request.source().aggregation(AggregationBuilders
                .terms("cityAgg")
                .field("city")
                .size(10)
        );
        request.source().aggregation(AggregationBuilders
                .terms("starAgg")
                .field("starName.keyword")
                .size(10)
        );
    }