Why would a "java.net.ConnectException: Connection timed out" exception occur when URL is up?

A java.net.ConnectException: Connection timed out error can occur when a Java application is unable to establish a network connection to the specified host. This can be caused by a number of factors, including:

  1. Network or firewall issues: Make sure that the network is functioning properly and that the host is not being blocked by a firewall or other network security device.

  2. Incorrect hostname or port: Make sure that you are using the correct hostname and port for the server in your Java application.

  3. The server is not running: Make sure that the server is running and reachable from your Java application.

  4. The server is experiencing high load or resource contention: If the server is under heavy load, it may be unable to accept new connections in a timely manner.

To troubleshoot this error, you will need to identify the cause of the problem and take the appropriate action to resolve it.

I hope this helps! Let me know if you have any questions.