如何获取节点状态HighLevelRESTClient ElasticSearch

import org.elasticsearch.action.admin.cluster.stats.ClusterStatsRequest;
import org.elasticsearch.action.admin.cluster.stats.ClusterStatsResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;

public class NodeStatusExample {
    public static void main(String[] args) {
        try (RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder("localhost:9200"))) {

            ClusterStatsRequest request = new ClusterStatsRequest();
            ClusterStatsResponse response = client.cluster().stats(request, RequestOptions.DEFAULT);

            int numberOfNodes = response.getNodes().getCount().getTotal();
            int numberOfIndices = response.getIndices().getCount();
            int numberOfShards = response.getIndices().getShards().getTotal();

            System.out.println("Number of nodes: " + numberOfNodes);
            System.out.println("Number of indices: " + numberOfIndices);
            System.out.println("Number of shards: " + numberOfShards);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}