Spring Boot @PreDestroy annotation not working

Question

I'm new to Spring Boot, and I've got a Spring Boot application that seems to be ignoring the @PreDestroy annotation - when I run from command line or via Eclipse, I'm never seeing the @PreDestroy code being run when application is shutdown (e.g. via ctrl-c)

Code is below ...

Application.java:

@SpringBootApplication
public class Application {

    @Autowired
    private MessageProcessor messageProcessor;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @PostConstruct
    public void init() {    
        messageProcessor.run();
    }

}

Message Processor Config:

@Configuration
public class MessageProcessorConfiguration {

    @Bean
    public MessageProcessor messageProcessor() {
        return new MessageProcessorImpl();
    }
}

Message Processor:

public class MessageProcessorImpl implements MessageProcessor {

    @Override
    public void run() {

        while (isActive()) {
           …
        }
    }


   @PreDestroy
   public void shutdown() { 
       System.out.println("MessageProcessorImpl - shutting down");
   }

}

Answer 1

Spring Boot register shutdown hook during context creation see org.springframework.context.support.AbstractApplicationContext#registerShutdownHookmethod. As result context must be closed on crtl+c combination (if you run your app through java -jar app.jar cmd) and which in turn triggers your @Predestroy method. This works for me.

I don't see any remarks in your code. I can suggest annotating your MessageProcessorImpl bean with @Component annotation instead of a manual @Bean declaration.

Answer 2

The @PreDestroy does not work when the Scope(value=ConfigurableBeanFactory.SCOPE_PROTOTYPE) is used on the bean since the bean's spawned with this method is not completely managed by the IOC container.

The @PreDestroy works when the Scope(value=ConfigurableBeanFactory.SCOPE_SINGLETON) is used on the bean.