Elasticsearch Java API不返回命中字段

Question

I have a problem with the java api for elasticsearch.

When I do a search like this:

MatchQueryBuilder query = QueryBuilders.matchQuery("_type", "booking");

SearchResponse searchResponse = client.prepareSearch().setQuery(query).execute().actionGet();

for (SearchHit hit : searchResponse.getHits()){
    Map<String, SearchHitField> fields = hit.getFields();
    System.out.println(fields.size());
}

my response never has fields, can somebody help me ?

I'am using:

elasticsearch java api 1.4.0 elasticsearch 1.4.0

and my data looks like

{
  "_index": "bookings",
  "_type": "booking",
  "_id": "50245171",
  "_score": 1,
  "_source": {
    "field1": "value1",
    "field2": "value2",
    "field3": "value3",
    ...
  }
}

Answer 1

Have you tried adding .addFields() to your query?

SearchResponse searchResponse = client.prepareSearch().setQuery(query).addFields("field1", "field2",...).execute().actionGet();

I'm not sure about all details, but I believe elasticsearch tries to send you as few data as possible. Which makes sense, since it should be fast and light.

In any case, are you by any chance indexing Booking objects? Because if you need the whole object again, you could also just fetch the source and transform that back into its original Booking object. For example:

ObjectMapper mapper = new ObjectMapper();
Booking booking = mapper.readValue(hit.getSourceAsString(), Booking.class);

ObjectMapper is from com.fasterxml.jackson.databind.ObjectMapper (should be included with elasticsearch I believe).

Answer 2

the fields are not responding as fields....

with hit.getSource() i got my information

Answer 3

The fields section of a hit includes the fields you explicitly ask for, by default that is none. You can use addField() or addFields() to add one or more fields to the request. This should populate the fields in the response for you.

The source in each hit contains the entire original object, so may well have data you do not need. Returning the source in this manner is often turned off to prevent sending this excess data around.

Answer 4

QueryBuilders.matchQuery()

seems to work with fields only

"_type" is a build-in properties of the index...

Try something like that :

    client.prepareSearch("bookings")
      .setTypes("booking")
      .setQuery(query)
      .execute()
      .actionGet();

Your query must be based on your document fields