ElasticSearch Java API to query and return single column instead of the whole json document

Question

While searching using java api in elaticsearch, I would like to retrieve only one column. Currently when I query using the Java API it returns the whole record like this: [{_id=123-456-7890, name=Wonder Woman, gender=FEMALE}, {_id=777-990-7890, name=Cat Woman, gender=FEMALE}]

The record above correctly matches the search condition shown in th . As shown in the code below:

        List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();


        SearchRequestBuilder srb = client.prepareSearch("heros")
                .setSearchType(SearchType.DFS_QUERY_THEN_FETCH);
        MatchQueryBuilder mqb;

        mqb = QueryBuilders.matchQuery("name", "Woman");
        srb.setQuery(mqb);
        SearchResponse response = srb.execute().actionGet();
        long totalHitCount = response.getHits().getTotalHits();

        System.out.println(response.getHits().getTotalHits());

        for (SearchHit hit : response.getHits()) {          
            result.add(hit.getSource());
        }

        System.out.println(result);

I want only one column to be returned. If I search for name I just want the full names back in a list: "Wonder Woman", "Cat Woman" only not the whole json record for each of them. If you think I need to iterate over the result list of maps in java please propose an example of how to do that in this case.

Answer 1

You can specify the fields to be returned from a search, per documentation. This can be set via SearchRequestBuilder.addFields(String... fields), ie:

    SearchRequestBuilder srb = client.prepareSearch("heros")
            .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
            .addFields("name");