Spring Remove all ApplicationListenerMethodAdapters on context close [SPR-17456]

Pramy opened SPR-17456 and commented

I know a bean implement ApplicationListener will be remove from Context when it destroy,

but ApplicationListenerMethodAdapter can't be remove 

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1.ParentContext invoke close method

2.Listener destroy

it did not implements ApplicationListener when use @EventListener

3.NamedContext destroy

it will invoke close method and publish close event, and parentContext will also publish close   event, ApplicationListenerMethodAdapter working will invoke conetext#getBean

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@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(DemoApplication.class, args);
        context.close();
    }

    class Listener implements DisposableBean {

        @EventListener(ContextClosedEvent.class)
        public void close(ApplicationEvent event) {
            System.out.println("---------------invoke listener"+event );
        }
        @Override
        public void destroy() throws Exception {
            System.out.println("--------------------listener destroy-----------------------");
        }
    }


    //1.insure NamedContextFactory initialize before listener
    //2.insure NamedContextFactory destroy after listener
    @Bean
    public Listener listener() {
        //3.initialize context values
        namedContextFactory().getInstance("demo",DemoApplication.class);
        return new Listener();
    }

    @Bean
    public NamedContextFactory<NamedContextFactory.Specification> namedContextFactory() {
        return new NamedContextFactory<NamedContextFactory.Specification>(Config.class
        ,"demo","demo") {};
    }

    @Configuration
    class Config{}
}

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Affects: 5.0.9, 5.0.10, 5.1.1, 5.1.2

Reference URL: https://github.com/Pramy/spring-listener-bug

Attachments: - demo.rar (32.98 kB)

Referenced from: pull request https://github.com/spring-projects/spring-framework/pull/2006

Comment From: jhoeller

There is indeed an issue with not clearing the internal ApplicationEventMulticaster (which may hold on to remaining ApplicationListenerMethodAdapters) on context close. As of 6.1, we reset those internal delegate references to null on close.

That said, the scenario above closes the contexts in the wrong order: You need to close the child context first, then the parent context, since the child may rely on the functionality of the parent still. If you close the parent first as shown above, the child context may still rely on it for all sorts of purposes and therefore fail during its own shutdown procedure.