How to perform some actions when an OSGi module is started/stopped

Issue

• I would like to perform some actions when my OSGi module is started/stopped. How can I achieve that?

Environment

• Liferay DXP 7.0+

Resolution

NOTE: The following resolution requires customization and should only be implemented at the discretion of your team. Liferay Support will not be able to assist with designing or implementing customizations.

• By leveraging OSGi annotations, you can get notified about lifecycle events in your Declarative Services components:
  • @Activate. This annotation marks a method that should be invoked when the component becomes satisfied and is activated.
  • @Deactivate. This annotation marks a method that should be invoked when the component is deactivated.
  • @Modified. This annotation marks a method that should be invoked when the component's configuration is modified.
• You can check Liferay source code for examples. For instance, SPAHelper class uses all 3 aforementioned annotations.

Additional Information

• Module Life Cycle
• Relevant blog posts (unofficial):
  
  • Liferay/OSGi Annotations - What they are and when to use them
  • Revisiting OSGi DS Annotations
• Declarative Services Specification