获取org.elasticsearch.transport.NodeDisconnectedException：[] [inet [localhost /127.0.0.1：9300]] [集群/节点

尝试使用

PreBuiltTransportClient

TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)        .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));

https://www.elastic.co/guide/zh-CN/elasticsearch/client/java-
api/current/transport-
client.html

另请注意，

TransportClient

客户端必须具有与集群中的节点相同的主版本（例如2.x或5.x）。客户端可以连接到具有不同次要版本（例如2.3.x）的群集，但是有可能不支持新功能。理想情况下，客户端应具有与群集相同的版本。

https://www.elastic.co/guide/zh-CN/elasticsearch/client/java-
api/current/client.html

更新资料

作为连接测试，请尝试执行以下简单程序：

import org.elasticsearch.client.transport.TransportClient;import org.elasticsearch.common.settings.Settings;import org.elasticsearch.common.transport.InetSocketTransportAddress;import org.elasticsearch.transport.client.PreBuiltTransportClient;import java.net.InetAddress;import java.net.UnknownHostException;public class App {    public static void main(String[] args) throws UnknownHostException {        // The following settings aren't strictly necessary, because the default cluster name is "elasticsearch".        Settings settings = Settings.builder().put("cluster.name", "elasticsearch").build();        TransportClient client = new PreBuiltTransportClient(settings);        client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));        System.out.println(client.connectedNodes());    }}

它应该打印到标准输出，如下所示：

[{luhcORJ}{luhcORJOSzSLPBeXocDsuQ}{mkTJpwIAQGuNYTHfRLqUIw}{127.0.0.1}{127.0.0.1:9300}]