Update of a record in elastic using elastic 8.7 javaclient

I attempted to add a couple new fields to an existing record in elastic search. The record is being updated, however all previously indexed fields have been cleared.

Is there something am I doing wrong?

Maven dependency

<dependency>
   <groupId>co.elastic.clients</groupId>
   <artifactId>elasticsearch-java</artifactId>
   <version>8.7.1</version>
</dependency>

Me code:

RestClientBuilder builder = RestClient.builder(new HttpHost(esIP, Integer.parseInt(esPort)));

RestClient restClient = builder.build();

//jsonMap indecates one record to be indexed 

br.operations(op -> op.index(idx -> idx.index((String) jsonMap.get("index_name")).id(jsonMap.get("id").toString()).document(jsonMap)));

Try following, you shoud exclude meta data (like index, id) from doc param.

    RestClient restClient = RestClient.builder(
            new HttpHost("localhost", 9200)).build();

    // Create the transport with a Jackson mapper
    ElasticsearchTransport transport = new RestClientTransport(
            restClient, new JacksonJsonpMapper());

    // And create the API client
    ElasticsearchClient client = new ElasticsearchClient(transport);


    HashMap jsonMap = new HashMap();
    jsonMap.put("field", "new value");

    UpdateRequest.Builder builder = new UpdateRequest.Builder();
    builder.index("index_name")
            .id("id")
            .doc(jsonMap); // exclude meta data (like index, id)

    UpdateResponse response = client.update(builder.build(), Object.class);

    System.out.println("Indexed with version " + response.version());

So you are developing low level client. And as your provided source code is not full enough to understand, I'm giving a sample Low Level Rest API over Remote Elasticsearch:

public class ElasticLowLevelRemote {
public static void main(String[] args) throws IOException {
Scanner input = new Scanner(System.in);
System.out.print("enter index ");
String indexInput = input.nextLine();
System.out.print("enter id ");
String id = input.nextLine();
RestClient restClient = RestClient.builder(
new HttpHost("ipaddress", port, "http"))
.setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(
new BasicCredentialsProvider() {{
setCredentials(AuthScope.ANY,
new UsernamePasswordCredentials("username", "password"));}})).build();
HttpEntity entity = new NStringEntity("{\n \"query\": {\n \"match\": {\n \"_id\": \"" + id + "\"\n }\n }\n}",
ContentType.APPLICATION_JSON);
Response response = restClient.performRequest(
"GET", "/"+indexInput+"/_search",
Collections.emptyMap(),
entity);
String jsonResponse = EntityUtils.toString(response.getEntity());
ObjectMapper mapper = new ObjectMapper();
Object json = mapper.readValue(jsonResponse, Object.class);
String formattedJson = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(json);
System.out.println(formattedJson);
restClient.close();
}
}