Affects: 5.2.5.RELEASE

Reproduction steps

  1. Create a command-line tool with CommandLineRunner.
  2. Add a Spring bean that: a. Starts a background thread in the constructor. b. Implements Closeable and terminate the background thread when calling its close().
  3. Run the command-line tool.

Expected results

Spring will call the shutdown hooks after the main function exits, call close() on the bean, stop the background thread, and terminate the whole command-line tool.

Actual results

The command will continue running with the background thread until the user pressing ctrl+C.

A simple demo for this problem is at https://github.com/johnlinp/misc-demo/tree/master/unstoppable-spring-boot-command-line-runner. Problem description and logs are attached in the README.

Comment From: wilkinsona

Thanks for the sample. It's the JVM rather than Spring that calls the shutdown hooks. The JVM calls the hooks when it is shutting down. It will shutdown when all of the threads that are alive are daemon threads. The background thread that you have started is a non-daemon thread which prevents the JVM from shutting down and, therefore, prevents the shutdown hooks from being called.

Comment From: johnlinp

I see. Thank you so much for the information!