Timeout exception while connecting to opensearch java client

Question

Trying to connect opensearch [AWS] via JavaClient and followed this blog. We don't have ssl authentication enabled in AWS for this demo.

public void connect(){
    try {
        CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY,
                new UsernamePasswordCredentials("es_cluster_username", "es_password"));

        RestClient restClient = RestClient.builder(new HttpHost("es-demo-cluster", 9200, "https"))
                .setHttpClientConfigCallback(httpClientBuilder -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider)).build();

        OpenSearchTransport transport = new RestClientTransport(restClient, jacksonJsonpMapper);
        OpenSearchClient openSearchClient = new OpenSearchClient(transport);
        boolean isConneted = openSearchClient.ping().value();
        if (isConneted) {
            log.info("ES connected ");
        } else {
            log.error("ES NOT connected");
        }
    } catch (Exception e) {
        log.error("Failed to connect to ES ");
    }
}
 

But getting Timeout exception here :

> java.net.ConnectException: Timeout connecting to [host:9200]
    at org.opensearch.client.RestClient.extractAndWrapCause(RestClient.java:953)
    at org.opensearch.client.RestClient.performRequest(RestClient.java:332)
    at org.opensearch.client.RestClient.performRequest(RestClient.java:320)
    at org.opensearch.client.transport.rest_client.RestClientTransport.performRequest(RestClientTransport.java:142)

dependencies :

<dependency>
    <groupId>org.opensearch.client</groupId>
    <artifactId>opensearch-rest-client</artifactId>
    <version>2.5.0</version>
</dependency>
<dependency>
    <groupId>org.opensearch.client</groupId>
    <artifactId>opensearch-java</artifactId>
    <version>2.3.0</version>
</dependency>

Our ES service is hosted in AWS and the demo endpoint[es-demo-cluster] is public. Able to do curl "es_endpoint[es-demo-cluster]" but connecting via Java client is throwing an exception. Can someone help with this?