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---
layout: default
title: Java high-level REST client
nav_order: 60
---
# Java high-level REST client
Although the OpenSearch Java high-level REST client is still usable, we recommend that you use the [OpenSearch Java client]({{site.url}}{{site.baseurl}}/clients/java/), which replaces the existing Java high-level REST client.
{: .note}
The OpenSearch Java high-level REST client lets you interact with your OpenSearch clusters and indices through Java methods and data structures rather than HTTP methods and JSON.
## Setup
To start using the OpenSearch Java high-level REST client, ensure that you have the following dependency in your project's `pom.xml` file:
```
<dependency>
<groupId>org.opensearch.client</groupId>
<artifactId>opensearch-rest-high-level-client</artifactId>
<version>{{site.opensearch_version}}</version>
</dependency>
```
You can now start your OpenSearch cluster. The OpenSearch 1.x high-level REST client works with the 1.x versions of OpenSearch.
The following example uses credentials that come with the default OpenSearch configuration. If youre using the high-level REST client with your own OpenSearch cluster, be sure to change the code to use your own credentials.
## Sample code
```java
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
import org.opensearch.action.delete.DeleteRequest;
import org.opensearch.action.delete.DeleteResponse;
import org.opensearch.action.get.GetRequest;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.index.IndexRequest;
import org.opensearch.action.index.IndexResponse;
import org.opensearch.action.support.master.AcknowledgedResponse;
import org.opensearch.client.RequestOptions;
import org.opensearch.client.RestClient;
import org.opensearch.client.RestClientBuilder;
import org.opensearch.client.RestHighLevelClient;
import org.opensearch.client.indices.CreateIndexRequest;
import org.opensearch.client.indices.CreateIndexResponse;
import org.opensearch.common.settings.Settings;
import java.io.IOException;
import java.util.HashMap;
public class RESTClientSample {
public static void main(String[] args) throws IOException {
//Point to keystore with appropriate certificates for security.
System.setProperty("javax.net.ssl.trustStore", "/full/path/to/keystore");
System.setProperty("javax.net.ssl.trustStorePassword", "password-to-keystore");
//Establish credentials to use basic authentication.
//Only for demo purposes. Do not specify your credentials in code.
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY,
new UsernamePasswordCredentials("admin", "admin"));
//Create a client.
RestClientBuilder builder = RestClient.builder(new HttpHost("localhost", 9200, "https"))
.setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
@Override
public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
}
});
RestHighLevelClient client = new RestHighLevelClient(builder);
//Create a non-default index with custom settings and mappings.
CreateIndexRequest createIndexRequest = new CreateIndexRequest("custom-index");
createIndexRequest.settings(Settings.builder() //Specify in the settings how many shards you want in the index.
.put("index.number_of_shards", 4)
.put("index.number_of_replicas", 3)
);
//Create a set of maps for the index's mappings.
HashMap<String, String> typeMapping = new HashMap<String,String>();
typeMapping.put("type", "integer");
HashMap<String, Object> ageMapping = new HashMap<String, Object>();
ageMapping.put("age", typeMapping);
HashMap<String, Object> mapping = new HashMap<String, Object>();
mapping.put("properties", ageMapping);
createIndexRequest.mapping(mapping);
CreateIndexResponse createIndexResponse = client.indices().create(createIndexRequest, RequestOptions.DEFAULT);
//Adding data to the index.
IndexRequest request = new IndexRequest("custom-index"); //Add a document to the custom-index we created.
request.id("1"); //Assign an ID to the document.
HashMap<String, String> stringMapping = new HashMap<String, String>();
stringMapping.put("message:", "Testing Java REST client");
request.source(stringMapping); //Place your content into the index's source.
IndexResponse indexResponse = client.index(request, RequestOptions.DEFAULT);
//Getting back the document
GetRequest getRequest = new GetRequest("custom-index", "1");
GetResponse response = client.get(getRequest, RequestOptions.DEFAULT);
System.out.println(response.getSourceAsString());
//Delete the document
DeleteRequest deleteDocumentRequest = new DeleteRequest("custom-index", "1"); //Index name followed by the ID.
DeleteResponse deleteResponse = client.delete(deleteDocumentRequest, RequestOptions.DEFAULT);
//Delete the index
DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("custom-index"); //Index name.
AcknowledgedResponse deleteIndexResponse = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);
client.close();
}
}
```
## Elasticsearch OSS Java high-level REST client
We recommend using the OpenSearch client to connect to OpenSearch clusters, but if you must use the Elasticsearch OSS Java high-level REST client, version 7.10.2 of the Elasticsearch OSS client also works with the 1.x versions of OpenSearch.
### Migrating to the OpenSearch Java high-level REST client
Migrating from the Elasticsearch OSS client to the OpenSearch high-level REST client is as simple as changing your Maven dependency to one that references [OpenSearch's dependency](#setup).
Afterward, change all references of `org.elasticsearch` to `org.opensearch`, and you're ready to start submitting requests to your OpenSearch cluster.