Elasticsearch phrase prefix query on multiple fields
The text query that you are using has been deprecated (effectively renamed) a while ago in favour of the match query. The match query supports a single field, but you can use the multi_match query which supports the very same options and allows to search on multiple fields. Here is an example that should be helpful to you:
{ "query" : { "multi_match" : { "fields" : ["title", "subtitle"], "query" : "trying out ela", "type" : "phrase_prefix" } }}You can achieve the same using the Java API like this:
QueryBuilders.multiMatchQuery("trying out ela", "title", "subtitle") .type(MatchQueryBuilder.Type.PHRASE_PREFIX);