opensearch-docs-cn/_clients/java.md

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---
layout: default
title: Java client
nav_order: 65
---
# Java client
The OpenSearch Java client allows you to interact with your OpenSearch clusters through Java methods and data structures rather than HTTP methods and raw JSON.
For example, you can submit requests to your cluster using objects to create indices, add data to documents, or complete some other operation using the client's built-in methods.
## Install the client
To start using the OpenSearch Java client, ensure that you have the following dependencies in your project's `pom.xml` file:
```
<dependency>
<groupId>org.opensearch.client</groupId>
<artifactId>opensearch-rest-client</artifactId>
<version>{{site.opensearch_version}}</version>
</dependency>
<dependency>
<groupId>org.opensearch.client</groupId>
<artifactId>opensearch-java</artifactId>
<version>2.0.0</version>
</dependency>
```
If you're using Gradle, add the following dependencies to your project.
```
dependencies {
implementation 'org.opensearch.client:opensearch-rest-client: {{site.opensearch_version}}'
implementation 'org.opensearch.client:opensearch-java:2.0.0'
}
```
You can now start your OpenSearch cluster.
## Security
Before using the REST client in your Java application, you must configure the application's truststore to connect to the security plugin. If you are using self-signed certificates or demo configurations, you can use the following command to create a custom truststore and add in root authority certificates.
If you're using certificates from a trusted Certificate Authority (CA), you don't need to configure the truststore.
```bash
keytool -import <path-to-cert> -alias <alias-to-call-cert> -keystore <truststore-name>
```
You can now point your Java client to the truststore and set basic authentication credentials that can access a secure cluster (refer to the sample code below on how to do so).
If you run into issues when configuring security, see [common issues]({{site.url}}{{site.baseurl}}/troubleshoot/index) and [troubleshoot TLS]({{site.url}}{{site.baseurl}}/troubleshoot/tls).
## Sample data
This section uses a class called `IndexData`, which is a simple Java class that stores basic data and methods. For your own OpenSearch cluster, you might find that you need a more robust class to store your data.
### IndexData class
```java
static class IndexData {
private String firstName;
private String lastName;
public IndexData(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
@Override
public String toString() {
return String.format("IndexData{first name='%s', last name='%s'}", firstName, lastName);
}
}
```
## Initialize the client with SSL and TLS enabled
This code example uses basic credentials that come with the default OpenSearch configuration. If youre using the Java client with your own OpenSearch cluster, be sure to change the code to use your own credentials.
The following sample code initializes a client with SSL and TLS enabled:
```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.client.RestClient;
import org.opensearch.client.RestClientBuilder;
import org.opensearch.client.base.RestClientTransport;
import org.opensearch.client.base.Transport;
import org.opensearch.client.json.jackson.JacksonJsonpMapper;
import org.opensearch.client.opensearch.OpenSearchClient;
import org.opensearch.client.opensearch._global.IndexRequest;
import org.opensearch.client.opensearch._global.IndexResponse;
import org.opensearch.client.opensearch._global.SearchResponse;
import org.opensearch.client.opensearch.indices.*;
import org.opensearch.client.opensearch.indices.put_settings.IndexSettingsBody;
import java.io.IOException;
public class OpenSearchClientExample {
public static void main(String[] args) {
RestClient restClient = null;
try{
System.setProperty("javax.net.ssl.trustStore", "/full/path/to/keystore");
System.setProperty("javax.net.ssl.trustStorePassword", "password-to-keystore");
//Only for demo purposes. Don't specify your credentials in code.
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY,
new UsernamePasswordCredentials("admin", "admin"));
//Initialize the client with SSL and TLS enabled
restClient = RestClient.builder(new HttpHost("localhost", 9200, "https")).
setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
@Override
public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
}
}).build();
Transport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
OpenSearchClient client = new OpenSearchClient(transport);
}
}
}
```
## OpenSearch client examples
This section has sample code that shows you how to create an index with non-default settings, add a document to the index, search for the document, delete the document, and finally delete the index.
### Create an index with non-default settings
```java
String index = "sample-index";
CreateRequest createIndexRequest = new CreateRequest.Builder().index(index).build();
client.indices().create(createIndexRequest);
IndexSettings indexSettings = new IndexSettings.Builder().autoExpandReplicas("0-all").build();
IndexSettingsBody settingsBody = new IndexSettingsBody.Builder().settings(indexSettings).build();
PutSettingsRequest putSettingsRequest = new PutSettingsRequest.Builder().index(index).value(settingsBody).build();
client.indices().putSettings(putSettingsRequest);
```
### Index data
```java
IndexData indexData = new IndexData("first_name", "Bruce");
IndexRequest<IndexData> indexRequest = new IndexRequest.Builder<IndexData>().index(index).id("1").value(indexData).build();
client.index(indexRequest);
```
### Search for the document
```java
SearchResponse<IndexData> searchResponse = client.search(s -> s.index(index), IndexData.class);
for (int i = 0; i< searchResponse.hits().hits().size(); i++) {
System.out.println(searchResponse.hits().hits().get(i).source());
}
```
### Delete the document
The following sample code deletes a document whose ID is 1.
```java
client.delete(b -> b.index(index).id("1"));
```
### Delete the index
```java
DeleteRequest deleteRequest = new DeleteRequest.Builder().index(index).build();
DeleteResponse deleteResponse = client.indices().delete(deleteRequest);
} catch (IOException e){
System.out.println(e.toString());
} finally {
try {
if (restClient != null) {
restClient.close();
}
} catch (IOException e) {
System.out.println(e.toString());
}
}
}
}
```
## Complete code sample
```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.client.RestClient;
import org.opensearch.client.RestClientBuilder;
import org.opensearch.client.base.RestClientTransport;
import org.opensearch.client.base.Transport;
import org.opensearch.client.json.jackson.JacksonJsonpMapper;
import org.opensearch.client.opensearch.OpenSearchClient;
import org.opensearch.client.opensearch._global.IndexRequest;
import org.opensearch.client.opensearch._global.IndexResponse;
import org.opensearch.client.opensearch._global.SearchResponse;
import org.opensearch.client.opensearch.indices.*;
import org.opensearch.client.opensearch.indices.put_settings.IndexSettingsBody;
import java.io.IOException;
public class OpenSearchClientExample {
public static void main(String[] args) {
RestClient restClient = null;
try{
System.setProperty("javax.net.ssl.trustStore", "/full/path/to/keystore");
System.setProperty("javax.net.ssl.trustStorePassword", "password-to-keystore");
//Only for demo purposes. Don't specify your credentials in code.
final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
credentialsProvider.setCredentials(AuthScope.ANY,
new UsernamePasswordCredentials("admin", "admin"));
//Initialize the client with SSL and TLS enabled
restClient = RestClient.builder(new HttpHost("localhost", 9200, "https")).
setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
@Override
public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
}
}).build();
Transport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
OpenSearchClient client = new OpenSearchClient(transport);
//Create the index
String index = "sample-index";
CreateRequest createIndexRequest = new CreateRequest.Builder().index(index).build();
client.indices().create(createIndexRequest);
//Add some settings to the index
IndexSettings indexSettings = new IndexSettings.Builder().autoExpandReplicas("0-all").build();
IndexSettingsBody settingsBody = new IndexSettingsBody.Builder().settings(indexSettings).build();
PutSettingsRequest putSettingsRequest = new PutSettingsRequest.Builder().index(index).value(settingsBody).build();
client.indices().putSettings(putSettingsRequest);
//Index some data
IndexData indexData = new IndexData("first_name", "Bruce");
IndexRequest<IndexData> indexRequest = new IndexRequest.Builder<IndexData>().index(index).id("1").value(indexData).build();
client.index(indexRequest);
//Search for the document
SearchResponse<IndexData> searchResponse = client.search(s -> s.index(index), IndexData.class);
for (int i = 0; i< searchResponse.hits().hits().size(); i++) {
System.out.println(searchResponse.hits().hits().get(i).source());
}
//Delete the document
client.delete(b -> b.index(index).id("1"));
// Delete the index
DeleteRequest deleteRequest = new DeleteRequest.Builder().index(index).build();
DeleteResponse deleteResponse = client.indices().delete(deleteRequest);
} catch (IOException e){
System.out.println(e.toString());
} finally {
try {
if (restClient != null) {
restClient.close();
}
} catch (IOException e) {
System.out.println(e.toString());
}
}
}
}
```