B4J Question Detect OS Shutdown

Have a look at this post by Erel
https://www.b4x.com/android/forum/threads/open-com-port-after-program-termination.108184/post-676346
It may give you some ideas.

Blueforcer said:

Is there a way to detect this?

Click to expand...

From my "quick" testing, no. @Deastrum's linked solution works under Windows when using CTRL-C to interrupt the program in a DOS command line session. I've not been able to use the solution to detect shutdowns via Task Manager, user logout, or system shutdowns. It does seem to work fairly well under Linux using the standard kill command, stopping it under systemd and shutting down/restarting Linux (tested on Ubuntu Server 18.04LTS). Note: The kill command can be used with various options that can be used to stop the .jar file without evoking the shutdown hook (and may be configured in such a way on other distributions).

while my testing , out of 5 stop calls it has called shutdown hook only once on windows shutdown