Changing the client’s initialization code

The TransportClient is typically initialized as follows:

Settings settings = Settings.builder()
        .put("cluster.name", "prod").build();

TransportClient transportClient = new PreBuiltTransportClient(settings)
        .addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9300))
        .addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9301));

The initialization of a RestHighLevelClient is different. It requires to provide a low-level client builder as a constructor argument:

RestHighLevelClient client = new RestHighLevelClient(
        RestClient.builder(
                new HttpHost("localhost", 9200, "http"),
                new HttpHost("localhost", 9201, "http")));

The RestHighLevelClient is thread-safe. It is typically instantiated by the application at startup time or when the first request is executed.

Once the RestHighLevelClient is initialized, it can be used to execute any of the supported APIs.

As with the TransportClient, the RestHighLevelClient must be closed when it is not needed anymore or when the application is stopped.

The code that closes the TransportClient:

transportClient.close();

must be replaced with:

client.close();