phenomenon:
When I started the project today, this project used the Elasticsearch service and found that the background reported this error:

Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: /127.0.0.1:9300

The error message is shown as below:

the reason:
This project uses the Elasticsearch search service, and the error message also prompts key information such as elasticsearch.transport. In fact, this error is caused by the failure of the Elasticsearch service to start successfully.

solution:
Restart the Elasticsearch service (if it doesn’t work once, try shutting it down and then restarting it).

I restarted several times before it succeeded.