Query builder not finding matches in Elastic Search JAVA high level reset client

Question

I wrote JAVA code that queries an Elastic Search index (served by Elastic Cloud - although I don't think that's relevant to this question).

With no query terms, the function returns all documents in the index as expected.

When I add a search query with Elastic's QueryBuilder syntax (this is part of Elastic's High Level REST Client for JAVA), no matches are found.

        RestHighLevelClient client = createHighLevelRestClient();
    int numberOfSearchHitsToReturn = 100; // defaults to 10

    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.size(numberOfSearchHitsToReturn);
    sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS)); 
    String[] includeFields = colNames.toArray(new String[colNames.size()]);
    String[] excludeFields = new String[] {}; // just need an exclude field in order to call
                                                // fetchSource
    sourceBuilder.fetchSource(includeFields, excludeFields);
    sourceBuilder.from(offset);
    sourceBuilder.size(limitParam);

    sourceBuilder.query(QueryBuilders.termQuery("firstname", query));

    SearchRequest searchRequest = new SearchRequest("contacts_" + list_id).source(sourceBuilder);
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    SearchHit[] hits = searchResponse.getHits().getHits();

hits is empty even when query = "RICARDO" and I do in fact have a document in this index with the value "ricardo" in the firstname field. Casing does not matter... setting query to "ricardo" also does not bring back any matches.

Why is this?

It is an issue with my implementation of the high level REST client library because the query works as expected in POSTMAN...

GET https://elastic:hWWVNZEk<hidden>7a6620ba18623.us-east-1.aws.found.io:9243/contacts_6/_search
{
    "query": 
    {
        "term":
        {
            "firstname":
            {
                "value": "ricardo"
            }
        }
    }
}

Does indeed return...

{
    "took": 1,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 3.5263605,
        "hits": [
            {
                "_index": "contacts_6_twtoatx8yv",
                "_type": "_doc",
                "_id": "2098",
                "_score": 3.5263605,
                "_source": {
                    "list_id": "6",
                    "contact_id": "2098",
                    "firstname": "RICARDO",
                    "middlename": "",
                    "lastname": "SMITH"
                }
            }
        ]
    }
}

Answer 1

I just tried your example and it works, although I removed a few lines of code, few fields, which I thought is unnecessary for example and should help you to debug the issue with your code.

First let me show you index mapping, sample docs and search query in JSON format and then I would show how to write the same search query using ES REST High-level client.

Index mapping

{
    "mappings": {
        "properties": {
            "firstname": {
                "type": "text"
            },
            "lastname": {
                "type": "text"
            }
        }
    }
}

Index sample doc

{
   "firstname" : "RICARDO",
   "lastname" : "SMITH"
}

JSON search query

{
    "query": {
        "term": {
            "firstname": {
                "value": "ricardo"
            }
        }
    }
}

REST high-level client code for the above query

        int numberOfSearchHitsToReturn = 100; // defaults to 10
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.size(numberOfSearchHitsToReturn);
        sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
        sourceBuilder.from(0);
        sourceBuilder.size(10);

        sourceBuilder.query(QueryBuilders.termQuery("firstname", "ricardo"));

        SearchRequest searchRequest = new SearchRequest("so_60628247").source(sourceBuilder);
        SearchResponse searchResponse = elasticsearchClient.search(searchRequest, RequestOptions.DEFAULT);

        // parse hit

        SearchHit[] searchHits = searchResponse.getHits().getHits();

Debugger show it returns the results

Very Important Note: For debugging purposes you can print the searchRequest.source.toString() which would show you the search JSON built from your java code and in my case it is below:

 {
  "from": 0,
  "size": 10,
  "timeout": "60s",
  "query": {
    "term": {
      "firstname": {
        "value": "ricardo",
        "boost": 1.0
      }
    }
  }
}