使用ElasticSearch Java API时遇到错误 "missing authentication credentials for REST request"

这是代码:

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

        CreateIndexRequest createIndexRequest = new CreateIndexRequest("user");
        CreateIndexResponse createIndexResponse = esClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("创建索引:" + acknowledged);

        esClient.close();

 原因是请求没有发送用户名和密码，没有通过验证导致的。

解决方法，使用RestClientBuilder，将ES登录用户名和密码添加进去，修改如下：

RestClientBuilder build = RestClient.builder(new HttpHost("localhost",9200,"http"));
        CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("elastic", "e5nTeAjoHTTPg--WgM49")); //用户名和密码
        build.setHttpClientConfigCallback((HttpAsyncClientBuilder httpAsyncClientBuilder) -> httpAsyncClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
        RestHighLevelClient esClient = new RestHighLevelClient(build);

        CreateIndexRequest createIndexRequest = new CreateIndexRequest("user");
        CreateIndexResponse createIndexResponse = esClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("创建索引:" + acknowledged);

        esClient.close();

顺利解决：