GetIndexRequest request = new GetIndexRequest(indexName);
boolean exists = restHighLevelClient.indices().exists(request, RequestOptions.DEFAULT);
restHighLevelClient.close();

public static void multiSearch() {
    var client = getClient();
    MultiSearchRequest msRequest = new MultiSearchRequest();
    SearchRequest request1 = new SearchRequest("movies");
    SearchSourceBuilder builder1 = new SearchSourceBuilder();
    builder1.query(QueryBuilders.matchQuery("title", "you"));
    request1.source(builder1);
    msRequest.add(request1);
    SearchRequest request2 = new SearchRequest("movies");
    SearchSourceBuilder builder2 = new SearchSourceBuilder();
    builder2.query(QueryBuilders.matchQuery("title", "life"));
    request2.source(builder2);
    msRequest.add(request2);
    try {
      MultiSearchResponse responses = client.msearch(msRequest, RequestOptions.DEFAULT);
      Arrays.asList(responses.getResponses()).stream()
      .map(item -> item.getResponse())
      .map(response -> response.getHits())
      .filter(hit -> hit != null)
      .forEach(hit -> hit.forEach(System.out::println));
    } catch (IOException e) {
      e.printStackTrace();
    }finally {
      close(client);
    }
  }
  /**
   * 关闭客户端
   * 
   * @param client
   */
  private static void close(RestHighLevelClient client) {
    try {
      client.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  /**
   * 获取客户端
   * 
   * @return
   */
  private static RestHighLevelClient getClient() {
    RestHighLevelClient client = new RestHighLevelClient(
        RestClient.builder(new HttpHost("elk-node01", 9200, "http"), new HttpHost("elk-node02", 9200, "http"),
            new HttpHost("elk-node03", 9200, "http")));
    return client;
  }