public void ESClientInit() {

    public static RestHighLevelClient client = null;
    
    //不需要使用者名稱和密碼的認證
    //client = new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", "9300", "http")));

    //需要使用者名稱和密碼的認證
    final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    credentialsProvider.setCredentials(AuthScope.ANY, 
 
new UsernamePasswordCredentials("userName", "password"));
    RestClientBuilder restClientBuilder = RestClient.builder(new HttpHost("127.0.0.1", "9300", "http"))
            .setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
                @Override
                public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpAsyncClientBuilder) {
                    
 
return httpAsyncClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
                }
            });
    client = new RestHighLevelClient(restClientBuilder);

}