What Java code library is used for Elasticsearch?

Question

Java

I decided to try to leave requests in elastic in Java, and I just can’t figure out which client to take and how to live with this stuff ..
There are three of the official clients.
There is a transport client in Java (which is on port 9300) - it seems to be deprecated, and it has its own for each version ...
There is a low-level REST client.
There is a high-level REST client that works through a low-level ...
Maybe someone will tell you something like Python's elasticsearch-dsl?
And I would like to know who uses what.

Answer 1

I will answer myself.
I will add, there is also a jest client - https://www.elastic.co/blog/found-java-clients-for...
But you need to drag the official transport client to it, mainly because of QueryBuilders, which is generally not bad ( I was starting to write classes for query-mapping myself)
----
In general, we tear everything out of jackson something like this

String query = "{\n" + 
      			"  \"query\": { \"match_all\": {}\n" + 
      			"  }" + 
      			"}\n" + 
      			"\n" + 
      			"";
    Response response = client.performRequest("GET","/offers_v1/offer/_search", new Hashtable<>(),
      	        new StringEntity(query));
      	
    HttpEntity entity = response.getEntity();
     
    ObjectMapper ob = new ObjectMapper()
        .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    ResponseHits responseHits = ob.readValue(entity.getContent(), ResponseHits.class);
    List<Hit> hits = responseHits.getHits().getHits();
    
    return Results.html("index").put("hits", hits);

To do this, we create the following ResponseHits classes. Hits, Hits

public class ResponseHits {
  private Hits hits;
}
public class Hits {
  private List<Hit> hits;
}
public class Hit {
  @JsonProperty(value = "_index")
    private String index;
  @JsonProperty(value = "_type")
    private String type;
  @JsonProperty(value = "_id")
    private String id;
  @JsonProperty(value = "_score")
    private Double score;
  @JsonProperty(value = "_source")
    private Hashtable<String, Object> source;
}