Elasticsearch：使用Java本机API重写查询

Question

I have this query in Elasticsearch that is working perfectly if I run it from the command line:

POST http://localhost:9200/YOUR_INDEX_NAME/_search/
{
  "size": 0,
  "aggs": {
    "autocomplete": {
      "terms": {
        "field": "autocomplete",
        "order": {
          "_count": "desc"
        },
        "include": {
          "pattern": "c.*"
        }
      }
    }
  },
  "query": {
    "prefix": {
      "autocomplete": {
        "value": "c"
      }
    }
  }
}

I have tried to rewrite it in java using the native client:

SearchResponse searchResponse2 = newClient.prepareSearch(INDEX_NAME)
            .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
            .setQuery("{\n" +
                "  \"size\": 0,\n" +
                "  \"aggs\": {\n" +
                "    \"autocomplete\": {\n" +
                "      \"terms\": {\n" +
                "        \"field\": \"autocomplete\",\n" +
                "        \"order\": {\n" +
                "          \"_count\": \"desc\"\n" +
                "        },\n" +
                "        \"include\": {\n" +
                "          \"pattern\": \"c.*\"\n" +
                "        }\n" +
                "      }\n" +
                "    }\n" +
                "  },\n" +
                "  \"query\": {\n" +
                "    \"prefix\": {\n" +
                "      \"autocomplete\": {\n" +
                "        \"value\": \"c\"\n" +
                "      }\n" +
                "    }\n" +
                "  }\n" +
                "}").get();
        for (SearchHit res : searchResponse2.getHits()){
            System.out.println(res.getSourceAsString());

        }

Seems, that I'm missing something in this translation process. Thanks in advance

Answer 1

The Java client setQuery() method doesn't take a String with the JSON query, you need to build the query using the QueryBuilders helper methods and build the aggregation your the AggregationBuilders helper methods.

In your case that would go like this:

// build the aggregation
TermsBuilder agg = AggregationBuilders.terms("autocomplete")
        .field("autocomplete")
        .include("c.*")
        .order(Terms.Order.count(false));

// build the query
SearchResponse searchResponse2 = newClient.prepareSearch(INDEX_NAME)
        .setSearchType(SearchType.DFS_QUERY_THEN_FETCH)
        .setSize(0)
        .setQuery(QueryBuilders.prefixQuery("autocomplete", "c"))
        .addAggregation(agg)
        .get();