java – spring 4.2应用程序事件用Spring MVC触发两次,为什么？

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我正在使用Spring 4.2.0.BUILD-SNAPSHOT events,由于某些原因我还没想到,监听器在发布任何事件后都会触发两次,无论是从ApplicationEvent还是任意事件扩展,但是在运行测试用例时一切都按预期工作,现在想知道是什么正在继续使用Spring MVC上下文中的注释驱动事件

事件发布界面

public interface ListingRegistrationService {
    public void registerListing(ListingResource listing);

}

@Component
class ListingRegistrationServiceImpl implements ListingRegistrationService{

    private final ApplicationEventPublisher publisher;

    @Autowired
    public ListingRegistrationServiceImpl(ApplicationEventPublisher publisher) {
        this.publisher = publisher;
    }

    @Override
    public void registerListing(ListingResource listing) {
       //process
        publisher.publishEvent(new ListingCreatedEvent(listing));
        System.out.println("Event above...");
    }

}

事件监听器

@EventListener
    @Async
    public void sendMailForSuggestedListing(Supplier<ListingResource> listingCreatedEvent)  {
        System.out.println("Event fired...");
    }

终点/切入点

public ResponseEntity<ResponseStatus> registerListing(@RequestBody @Valid ListingResource listing,BindingResult result) throws URISyntaxException {
       ResponseEntity<ResponseStatus> response = null;
       listingService.registerListing(listing); //  publish the event
       response = ResponseEntity.created(new URI(""));
         return response;
            }

结果：
事件被解雇……
事件被解雇……
以上活动..

I suspect indeed that the EventListener bean is registered twice or
something. You can enable
org.springframework.context.event.EventListenerMethodProcessor to
trace level to check what happens to this particular class.

– StéphaneNic??oll

跟踪
org.springframework.context.event.EventListenerMethodProcessorIt发生了两次事情

12:02:32,878 DEBUG ntext.event.EventListenerMethodProcessor: 138 - 1 @EventListener methods processed on bean 'mailServiceImpl': [public void com.service.MailServiceImpl.sendMailForSuggestedListing(com.service.events.CreationEvent)]
12:02:32,878 DEBUG ntext.event.EventListenerMethodProcessor: 138 - 1 @EventListener methods processed on bean 'mailServiceImpl': [public void com.service.MailServiceImpl.sendMailForSuggestedListing(com.service.events.CreationEvent)]
12:02:32,878 TRACE ntext.event.EventListenerMethodProcessor: 132 - No @EventListener annotations found on bean class: class com.service.MetaServiceImpl
12:02:32,878 TRACE ntext.event.EventListenerMethodProcessor: 132 - No @EventListener annotations found on bean class: class com.service.MetaServiceImpl

Java configuration

@Configuration
@ComponentScan(basePackages = {"com.**.domain",
        "com.**.repositories", "com.**.service",
        "com.**.security" })
@PropertySource(value = { "classpath:application.properties" })
public class ServiceConfig 


Configuration
@EnableWebMvc
@EnableSwagger
@EnableSpringDataWebSupport
@EnableMongoRepositories("com.**.repositories")
@ComponentScan(basePackages = {"com.**.config","com.**.rest.controllers","com.**.rest.tokens"})
public class WebConfig extends WebMvcConfigurerAdapter {

@Configuration
@EnableMongoRepositories("com.**.**.repositories")
public class MongoRepositoryConfig extends AbstractMongoConfiguration

解决方法:

我有同样的问题.对我来说……我注册了两次事件监听器,因为我在一个配置类中覆盖了我的整个包路径

@ComponentScan(  basePackages = {"my.root.package"} )
@Configuration
public class MyAppConfig {
      //... 
}

然后我在另一个配置类中手动添加了相同的eventListener bean,就像这样

@Configuration
public class SpringConfig {
    ...
    // SomeEventListener was located @ my.root.package.event and had @Component annotation
    @Bean 
    public SomeEventListener someEventListener() {
        return new SomeEventListener();
    }
    ...
}

导致它注册两次.

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