NoNodeAvailableException[None of the configured nodes are available: [{#transport#-1}{...}{127.0.0.1}{127.0.0.1:9300}]]

I have encountered same problem and i solved the mentioned issue by adding transport.host: localhost property in elasticsearch.yml file.

After adding it, it works as expected. I hope it will help other reader of this thread.

Just for reference, I am using 7.2 while I was trying to use

org.elasticsearch.client:transport:5.5.1

and following code to connect to my local cluster, and same error popped into my face.

public static void main(String... args) {
        TransportClient client = getClient();
        SearchResponse response = client.prepareSearch("cars").execute().actionGet();
        System.out.println(response);
    }

    private static TransportClient getClient() {
        TransportClient client = null;
        try {
            client = new PreBuiltTransportClient(
                    Settings.builder().put("client.transport.sniff", true)
                            .put("cluster.name", "elasticsearch").build())
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
            client.listedNodes();
        } catch (UnknownHostException e) {

        }
        return client;
    }

As I checked the ES console, it's already warned me of the version issues

exception caught on transport layer [Netty4TcpChannel{localAddress=/127.0.0.1:9300, remoteAddress=/127.0.0.1:62723}], closing connection
java.lang.IllegalStateException: Received handshake message from unsupported version: [5.0.0] minimal compatible version is: [6.8.0]

So I just use the new version to fix the error.

org.elasticsearch.client:transport:7.2.0