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.
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.
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).
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);
This code example uses basic credentials that come with the default OpenSearch configuration. If you’re using the Java client with your own OpenSearch cluster, be sure to change the code to use your own credentials.
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();
