How to set the boost for each field using MultiMatchQueryBuilder?

Question

The multi_match query supports field boosting via ^ notation in the json field as below

{
    "multi_match" : {
        "query" : "this is the best",
        "fields" : [ "number^5", "description^2" ]
    }
}

I want to achieve the same using java api, thus I am using MultiMatchQueryBuilder to construct the query as below:

final MultiMatchQueryBuilder query
        = new MultiMatchQueryBuilder(keyword, "number^5", "description^2");

But elastic search api is converting this query as below:

{
   "multi_match" : {
      "query" : "this is the test",
      "fields" : [
          "number^5.0^1.0",
          "description^2.0^1.0"
      ],
      "type" : "best_fields",
      "operator" : "OR",
      "slop" : 0,
      "prefix_length" : 0,
      "max_expansions" : 50,
      "lenient" : false,
      "zero_terms_query" : "NONE",
      "boost" : 1.0
   }
}

What should be the correct way to set boost for each fields from the query?

Answer 1

Try this:

final MultiMatchQueryBuilder query
        = new MultiMatchQueryBuilder(keyword).field("number",5).field("description",2);