dubbo中ServiceBeanExportedEvent的作用是什么

dubbo中ServiceBeanExportedEvent的作用是什么，相信很多沒有經(jīng)驗(yàn)的人對此束手無策，為此本文總結(jié)了問題出現(xiàn)的原因和解決方法，通過這篇文章希望你能解決這個問題。

ServiceBeanExportedEvent

dubbo-2.7.3/dubbo-config/dubbo-config-spring/src/main/java/org/apache/dubbo/config/spring/context/event/ServiceBeanExportedEvent.java

public class ServiceBeanExportedEvent extends ApplicationEvent {

    /**
     * Create a new ApplicationEvent.
     *
     * @param serviceBean {@link ServiceBean} bean
     */
    public ServiceBeanExportedEvent(ServiceBean serviceBean) {
        super(serviceBean);
    }

    /**
     * Get {@link ServiceBean} instance
     *
     * @return non-null
     */
    public ServiceBean getServiceBean() {
        return (ServiceBean) super.getSource();
    }
}

• ServiceBeanExportedEvent繼承了ApplicationEvent，其source為ServiceBean

ServiceBean

dubbo-2.7.3/dubbo-config/dubbo-config-spring/src/main/java/org/apache/dubbo/config/spring/ServiceBean.java

public class ServiceBean<T> extends ServiceConfig<T> implements InitializingBean, DisposableBean,
        ApplicationContextAware, ApplicationListener<ContextRefreshedEvent>, BeanNameAware,
        ApplicationEventPublisherAware {

        //......

    /**
     * @since 2.6.5
     */
    @Override
    public void export() {
        super.export();
        // Publish ServiceBeanExportedEvent
        publishExportEvent();
    }

    /**
     * @since 2.6.5
     */
    private void publishExportEvent() {
        ServiceBeanExportedEvent exportEvent = new ServiceBeanExportedEvent(this);
        applicationEventPublisher.publishEvent(exportEvent);
    }

        //......
}

• ServiceBean的export方法會publishExportEvent

ReferenceAnnotationBeanPostProcessor

dubbo-2.7.3/dubbo-config/dubbo-config-spring/src/main/java/org/apache/dubbo/config/spring/beans/factory/annotation/ReferenceAnnotationBeanPostProcessor.java

public class ReferenceAnnotationBeanPostProcessor extends AnnotationInjectedBeanPostProcessor implements
        ApplicationContextAware, ApplicationListener {

        //......

    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        if (event instanceof ServiceBeanExportedEvent) {
            onServiceBeanExportEvent((ServiceBeanExportedEvent) event);
        } else if (event instanceof ContextRefreshedEvent) {
            onContextRefreshedEvent((ContextRefreshedEvent) event);
        }
    }

    private void onServiceBeanExportEvent(ServiceBeanExportedEvent event) {
        ServiceBean serviceBean = event.getServiceBean();
        initReferenceBeanInvocationHandler(serviceBean);
    }

    private void initReferenceBeanInvocationHandler(ServiceBean serviceBean) {
        String serviceBeanName = serviceBean.getBeanName();
        // Remove ServiceBean when it's exported
        ReferenceBeanInvocationHandler handler = localReferenceBeanInvocationHandlerCache.remove(serviceBeanName);
        // Initialize
        if (handler != null) {
            handler.init();
        }
    }

        //......
}

• ReferenceAnnotationBeanPostProcessor實(shí)現(xiàn)了ApplicationListener的onApplicationEvent方法，接收到ServiceBeanExportedEvent事件時執(zhí)行onServiceBeanExportEvent，這里從localReferenceBeanInvocationHandlerCache移除，然后執(zhí)行ReferenceBeanInvocationHandler的init方法

小結(jié)

ServiceBeanExportedEvent繼承了ApplicationEvent，其source為ServiceBean；ServiceBean的export方法會publishExportEvent；ReferenceAnnotationBeanPostProcessor實(shí)現(xiàn)了ApplicationListener的onApplicationEvent方法，接收到ServiceBeanExportedEvent事件時執(zhí)行onServiceBeanExportEvent，這里從localReferenceBeanInvocationHandlerCache移除，然后執(zhí)行ReferenceBeanInvocationHandler的init方法

看完上述內(nèi)容，你們掌握dubbo中ServiceBeanExportedEvent的作用是什么的方法了嗎？如果還想學(xué)到更多技能或想了解更多相關(guān)內(nèi)容，歡迎關(guān)注億速云行業(yè)資訊頻道，感謝各位的閱讀！