Migrate Elasticsearch Builder classes to latest Java API 9.x

[rcbandit111]

I have this elasticsearch Java code to connect and get data:

Gradle dependencies:

implementation 'org.elasticsearch:elasticsearch:5.6.16'
implementation 'org.elasticsearch.client:transport:5.6.16'

import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.DocWriteResponse.Result;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.bulk.BackoffPolicy;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.bulk.Retry;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.get.MultiGetItemResponse;
import org.elasticsearch.action.get.MultiGetRequestBuilder;
import org.elasticsearch.action.get.MultiGetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexRequestBuilder;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.ClearScrollRequest;
import org.elasticsearch.action.search.ClearScrollResponse;
import org.elasticsearch.action.search.MultiSearchRequestBuilder;
import org.elasticsearch.action.search.MultiSearchResponse;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchScrollRequestBuilder;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.engine.DocumentMissingException;
import org.elasticsearch.index.reindex.BulkByScrollResponse;
import org.elasticsearch.index.reindex.DeleteByQueryAction;
import org.elasticsearch.index.reindex.DeleteByQueryRequestBuilder;
import org.elasticsearch.script.mustache.SearchTemplateRequestBuilder;
import org.elasticsearch.transport.client.PreBuiltTransportClient;


public class ESRepository {
    
  private TransportClient client;

 //.. java method to initialize client connection object


  protected SearchRequestBuilder getSearchRequestBuilder() {
    try {
      return client.prepareSearch();
    } catch (Exception exception) {
      throw Exception();
    }
  }


  public SearchResponse search(SearchRequestBuilder builder) {
    try {
      return builder.get();
    } catch (Exception exception) {
      throw Exception();
    }
  }

  public SearchScrollRequestBuilder getSearchScrollRequestBuilder(String scrollId) {
    try {
      return client.prepareSearchScroll(scrollId);
    } catch (Exception exception) {
      throw Exception();
    }
  }

  public SearchResponse searchScroll(SearchScrollRequestBuilder builder) {
    try {
      return builder.get();
    } catch (Exception exception) {
      throw Exception();
    }
  }
}

..............


import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.script.ScriptType;
import org.elasticsearch.script.mustache.SearchTemplateRequestBuilder;
import org.elasticsearch.script.mustache.SearchTemplateResponse;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.nested.NestedAggregationBuilder;
import org.elasticsearch.search.sort.SortBuilder;

public class Search extends ESRepository {



public SearchResponse searchScript(Map<String, Object> parameters, String scriptName) {
    SearchTemplateRequestBuilder searchTemplateRequestBuilder = getSearchTemplateRequestBuilder();
    SearchTemplateResponse response = searchTemplateRequestBuilder.setScript(scriptName)
        .setScriptType(ScriptType.STORED).setScriptParams(parameters)
                        .setRequest(new SearchRequest(this.readIndex)).get();
    return response.getResponse();
  }
}


Map<String, Object> parameters = new HashMap<>();
    parameters.put("offset", offset);
    parameters.put("limit", limit);
    parameters.put("users", searchQuery);

SearchResponse response = ESRepository.searchScript(parameters, "search_template");

For latest version:

implementation 'co.elastic.clients:elasticsearch-java:9.2.0'
implementation 'org.elasticsearch.client:elasticsearch-rest-client:9.2.0'

I can't find a replacement for above builder classes. Do you know how I can migrate the code and keep the same structure/logic if possible?

[l-trotta]

Hello! Jumping directly from version 5 to 9 is going to be quite hard ^^" for starters, it's not even the same repository: version 5 was the high level rest client, which has been since deprecated and replaced with elasticsearch-java in version 7.

Honestly if the codebase is limited in size, I'd suggest rewriting it from scratch, since almost nothing is going to be the same. If the codebase is larger, then you can follow first a migration guide from the high level rest client version 7 to version 8 of elasticsearch-java: https://www.elastic.co/blog/switching-from-the-java-high-level-rest-client-to-the-new-java-api-client.

Then from version 8 to 9 of elasticsearch-java we have every breaking change explained in the release notes: https://www.elastic.co/docs/release-notes/elasticsearch/clients/java/9-0-0, but they should be minimal compared to the previous step.

[rcbandit111]

@l-trotta Can you show me code example how to migrate my code, please?

[l-trotta]

To start, check the getting started section of our docs to see how to connect the client to the server instance, then if you want to know how to build a search template query with a script, first of all I'd check the server documentation for search template, since it could have been changed since version 5.

Once you have an idea of the query you want to run, you can rewrite it using the java client knowing that the client tries to follow the structure of the original json as closely as possible, for example:

GET my-index/_search/template
{
  "id": "my-search-template",
  "params": {
    "query_string": "hello world",
    "from": 0,
    "size": 10
  }
}

becomes

client.searchTemplate(s -> s
    .index("my-index")
    .id("my-search-template")
    .params(Map.of(
        "query_string", JsonData.of("hello world"),
        "from",JsonData.of(0),
        "size",JsonData.of(10)
        ))
);

this sends the query directly to the server, no builders needed!

Lastly, if you check the api documentation, on the right side you'll find examples in many languages, including Java