Monitor task executed multiple times

[KUANG QING]

When I deploy the task to the server, the pagechange function is executed three times (I think there may be a time limit, otherwise it will be executed more times).

public class PageChangesListener  implements  InitializingBean, DisposableBean {

    @Inject
    private SubmitKnowledgeDaoImpl submitKnowledgeDao;

    @Inject
    private SubmittedPageIdDaoImpl submittedPageIdDao;


    @ConfluenceImport
    private EventPublisher eventPublisher;

    private final static Logger logger = LoggerFactory.getLogger("atlassian.plugin");

    @Inject
    public PageChangesListener(final EventPublisher eventPublisher) {

        this.eventPublisher = eventPublisher;
    }

    @Override
    public void afterPropertiesSet() {
        this.eventPublisher.register(this);
    }

    @Override
    public void destroy() throws Exception {
        this.eventPublisher.unregister(this);
    }

    @EventListener
    public void pageChange(PageUpdateEvent pageUpdateEvent) {
        logger.info("发生页面修改事件");
        long pageId = pageUpdateEvent.getPage().getId();
        String title = pageUpdateEvent.getPage().getTitle();
        String author = pageUpdateEvent.getPage().getCreator().getName();
        Integer cid = null;
        String content = pageUpdateEvent.getContent().getBodyAsString();
        SubmitToKnowledgeDatabaseBean submitToKnowledgeDatabaseBean = new SubmitToKnowledgeDatabaseBean();
        submitToKnowledgeDatabaseBean.setCid(cid);
        submitToKnowledgeDatabaseBean.setPageId(pageId);
        submitToKnowledgeDatabaseBean.setContent(content);
        submitToKnowledgeDatabaseBean.setTitle(title);
        submitToKnowledgeDatabaseBean.setAuthorName(author);
        try {

            Long timeStamp = System.currentTimeMillis() / 1000;
            Integer authorId = submitKnowledgeDao.getAuthorIdByName(submitToKnowledgeDatabaseBean.getAuthorName());


            if (submittedPageIdDao.pageHasSubmittedToKnowledge(submitToKnowledgeDatabaseBean.getPageId())) {
                logger.info("本页面已经提交过知识库，准备更新知识库");
                //已经提交过

                Long did = submittedPageIdDao.getCidOfPage(submitToKnowledgeDatabaseBean.getPageId());
                submitToKnowledgeDatabaseBean.setCid(submitKnowledgeDao.getCidByDid(did));


                logger.info(did + "");

                boolean tag = submitKnowledgeDao.updatePageContent(did, submitToKnowledgeDatabaseBean.getCid()
                        , submitToKnowledgeDatabaseBean.getTitle(), submitToKnowledgeDatabaseBean.getContent(), timeStamp);
                if (tag) {
                    tag = submitKnowledgeDao.updateLink(submitToKnowledgeDatabaseBean.getCid(), did);
                    if (tag) {
                        tag = submitKnowledgeDao.updateWIKIEditions(did, submitToKnowledgeDatabaseBean.getCid()
                                , submitToKnowledgeDatabaseBean.getAuthorName(), authorId, timeStamp,
                                "", submitToKnowledgeDatabaseBean.getTitle(), submitToKnowledgeDatabaseBean.getContent());
                        logger.info("成功更新知识库");

                    }
                }
            }
        } catch (Exception e) {
            logger.info(e.getMessage());
            e.printStackTrace();
        }
    }
}

And throw such an exception

java.lang.NullPointerException
at java.util.Objects.requireNonNull(Objects.java:203)
at com.fr.plugin.confluence.listener.page.impl.PageUpdateListener.getLastPageBean(PageUpdateListener.java:31)
at com.fr.plugin.confluence.bean.compare.ComparedPageBean.<init>(ComparedPageBean.java:29)
at com.fr.plugin.confluence.listener.PageEventListener.handleEvent(PageEventListener.java:35)
at com.atlassian.event.legacy.LegacyListenerHandler$LegacyListenerInvoker.invoke(LegacyListenerHandler.java:51)
at com.atlassian.confluence.event.ConfluenceListenerHandlersConfiguration$TimedListenerInvoker.invoke(ConfluenceListenerHandlersConfiguration.java:96)
at com.atlassian.confluence.event.ConfluenceEventDispatcher$VCacheRequestContextRunnableFactory$1.lambda$run$0(ConfluenceEventDispatcher.java:93)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.lambda$doInRequestContext$0(VCacheRequestContextOperations.java:50)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContextInternal(VCacheRequestContextManager.java:84)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContext(VCacheRequestContextManager.java:68)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.doInRequestContext(VCacheRequestContextOperations.java:49)
at com.atlassian.confluence.event.ConfluenceEventDispatcher$VCacheRequestContextRunnableFactory$1.run(ConfluenceEventDispatcher.java:93)
at com.atlassian.event.internal.AsynchronousAbleEventDispatcher.dispatch(AsynchronousAbleEventDispatcher.java:85)
at com.atlassian.event.internal.EventPublisherImpl.invokeListeners(EventPublisherImpl.java:227)
at com.atlassian.event.internal.EventPublisherImpl.publish(EventPublisherImpl.java:112)
at com.atlassian.confluence.event.TimingEventPublisher.publish(TimingEventPublisher.java:76)
at com.atlassian.confluence.pages.DefaultPageManager.publishUpdateEvent(DefaultPageManager.java:1703)
at com.atlassian.confluence.core.DefaultContentEntityManager.saveContentEntity(DefaultContentEntityManager.java:167)
at com.atlassian.confluence.pages.DefaultPageManager.saveContentEntity(DefaultPageManager.java:1410)
at sun.reflect.GeneratedMethodAccessor3757.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at com.atlassian.spring.interceptors.SpringProfilingInterceptor.invoke(SpringProfilingInterceptor.java:16)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at com.atlassian.confluence.util.profiling.ConfluenceMonitoringMethodInterceptor.invoke(ConfluenceMonitoringMethodInterceptor.java:36)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
at com.sun.proxy.$Proxy148.saveContentEntity(Unknown Source)
at com.atlassian.confluence.links.DefaultRelatedContentRefactorer.persistBodyModificationToContent(DefaultRelatedContentRefactorer.java:254)
at com.atlassian.confluence.links.DefaultRelatedContentRefactorer.updateReferences(DefaultRelatedContentRefactorer.java:248)
at com.atlassian.confluence.links.DefaultRelatedContentRefactorer.updateReferrers(DefaultRelatedContentRefactorer.java:114)
at com.atlassian.confluence.links.DefaultRelatedContentRefactorer.updateReferrers(DefaultRelatedContentRefactorer.java:43)
at com.atlassian.confluence.links.RelatedContentRefactoringListener.handleEvent(RelatedContentRefactoringListener.java:62)
at sun.reflect.GeneratedMethodAccessor3310.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.atlassian.event.internal.SingleParameterMethodListenerInvoker.invoke(SingleParameterMethodListenerInvoker.java:42)
at com.atlassian.confluence.event.ConfluenceListenerHandlersConfiguration$TimedListenerInvoker.invoke(ConfluenceListenerHandlersConfiguration.java:96)
at com.atlassian.confluence.event.ConfluenceEventDispatcher$VCacheRequestContextRunnableFactory$1.lambda$run$0(ConfluenceEventDispatcher.java:93)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.lambda$doInRequestContext$0(VCacheRequestContextOperations.java:50)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContextInternal(VCacheRequestContextManager.java:84)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContext(VCacheRequestContextManager.java:68)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.doInRequestContext(VCacheRequestContextOperations.java:49)
at com.atlassian.confluence.event.ConfluenceEventDispatcher$VCacheRequestContextRunnableFactory$1.run(ConfluenceEventDispatcher.java:93)
at com.atlassian.event.internal.AsynchronousAbleEventDispatcher.dispatch(AsynchronousAbleEventDispatcher.java:85)
at com.atlassian.event.internal.EventPublisherImpl.invokeListeners(EventPublisherImpl.java:227)
at com.atlassian.event.internal.EventPublisherImpl.publish(EventPublisherImpl.java:112)
at com.atlassian.confluence.event.TimingEventPublisher.publish(TimingEventPublisher.java:76)
at com.atlassian.confluence.pages.DefaultPageManager.publishUpdateEvent(DefaultPageManager.java:1703)
at com.atlassian.confluence.core.DefaultContentEntityManager.saveContentEntity(DefaultContentEntityManager.java:186)
at com.atlassian.confluence.pages.DefaultPageManager.saveContentEntity(DefaultPageManager.java:1457)