java连接ES集群，ES带有账号密码

连接带有账号密码的ES集群，可以使用Java High Level Rest Client。下面是一个简单的Java代码示例，展示如何连接带有账号密码的ES集群:

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.sniff.Sniffer;
import org.elasticsearch.common.settings.Settings;

import java.util.Arrays;

public class ESClient {
    private static final String[] esHosts = {"localhost:9200"};
    private static final String userName = "yourUserName";
    private static final String password = "yourPassword";
    private static final String schema = "https";

    private static RestHighLevelClient client;

    static {
        HttpHost[] hosts = Arrays.stream(esHosts).map(HttpHost::create).toArray(HttpHost[]::new);
        client = new RestHighLevelClient(RestClient.builder(hosts)
                .setHttpClientConfigCallback(httpAsyncClientBuilder -> httpAsyncClientBuilder
                        .setDefaultCredentialsProvider(() -> new UsernamePasswordCredentials(userName, password)))
                .setRequestConfigCallback(requestConfigBuilder -> requestConfigBuilder
                        .setConnectTimeout(5000)
                        .setSocketTimeout(60000)));
    }

    public static RestHighLevelClient getClient() {
        return client;
    }

    public static void closeClient() {
        try {
            client.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

在上面的示例代码中，我们使用RestClient.builder()创建了RestHighLevelClient实例，并通过setHttpClientConfigCallback()设置了HTTP客户端的配置。其中，setDefaultCredentialsProvider()方法设置了用户名和密码，用于连接ES集群。如果ES集群启用了HTTPS，则需要设置schema为https。

需要注意的是，这里的示例代码并没有启用连接池，如果需要使用连接池，可以参考Elasticsearch官方文档中提供的Rest Client连接池实现。