我正在使用 Spring Boot 实现通知并使用 @Async 通知不同线程中的用户.
没有这个注释，一切正常，但是当我把它放在我用来通知的方法上时，只有一个可观察的实体，观察者不会得到通知，我得到了这个堆栈跟踪:
Unexpected exception occurred invoking async method: public void pt.ulisboa.tecnico.socialsoftware.tutor.notifications.NotificationServic
e.notifyObservers(package.notifications.Observable,package.notifications.domain.Notification,ppackage.user.User)
org.hibernate.exception.GenericJDBCException: could not initialize a collection: [package.course.CourseExecution.users#11]
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:47) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.collection.plan.AbstractLoadPlanBasedCollectionInitializer.initialize(AbstractLoadPlanBasedCollectionInitializer.java:97) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:707) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.event.internal.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:76) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:108) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final] at org.hibernate.internal.SessionImpl.initializeCollection(SessionImpl.java:2145) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection$4.doWork(AbstractPersistentCollection.java:589) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:264) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:585) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:149) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.collection.internal.PersistentSet.toString(PersistentSet.java:327) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at java.base/java.lang.String.valueOf(String.java:2951) ~[na:na]
at java.base/java.io.PrintStream.println(PrintStream.java:897) ~[na:na]
at package.course.CourseExecution.Notify(CourseExecution.java:210) ~[classes/:na]
at package.notifications.NotificationService.notifyObservers(NotificationService.java:82) ~[classes/:na]
at package.notifications.NotificationService$$FastClassBySpringCGLIB$$d43e740c.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366) ~[spring-tx-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99) ~[spring-tx-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.aop.interceptor.AsyncExecutionInterceptor.lambda$invoke$0(AsyncExecutionInterceptor.java:115) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
Caused by: org.postgresql.util.PSQLException: This statement has been closed.
at org.postgresql.jdbc.PgStatement.checkClosed(PgStatement.java:705) ~[postgresql-42.2.8.jar:42.2.8]
at org.postgresql.jdbc.PgPreparedStatement.setInt(PgPreparedStatement.java:270) ~[postgresql-42.2.8.jar:42.2.8]
at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.setInt(HikariProxyPreparedStatement.java) ~[HikariCP-3.4.1.jar:na]
at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor$1.doBind(IntegerTypeDescriptor.java:46) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final] at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:73) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final] at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:276) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final] at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:271) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final] at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.bindPositionalParameters(AbstractLoadPlanBasedLoader.java:320) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.bindParameterValues(AbstractLoadPlanBasedLoader.java:291) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.prepareQueryStatement(AbstractLoadPlanBasedLoader.java:210) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeQueryStatement(AbstractLoadPlanBasedLoader.java:162) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.plan.exec.internal.AbstractLoadPlanBasedLoader.executeLoad(AbstractLoadPlanBasedLoader.java:104) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
at org.hibernate.loader.collection.plan.AbstractLoadPlanBasedCollectionInitializer.initialize(AbstractLoadPlanBasedCollectionInitializer.java:87) ~[hibernate-core-5.4.9.Final.jar:5.4.9.Final]
... 25 common frames omitted
Caused by异常消息总是相同的，另一个，并不总是跟踪中提到的方法是:
@Async("notifyExecutor") // Even with the default executor, the error occurs
@Retryable(
value = { SQLException.class },
backoff = @Backoff(delay = 5000))
@Transactional(isolation = Isolation.REPEATABLE_READ)
public void notifyObservers(Observable observable, Notification notification, User exclude) {
observable.Notify(notification, exclude);
}
@Autowired ) @Retryable(value = { SQLException.class }, backoff = @Backoff(delay = 5000))
@Transactional(isolation = Isolation.REPEATABLE_READ)
public AnnouncementDto createAnnouncement(AnnouncementDto announcementDto) {
checkIfConsistentAnnouncement(announcementDto);
User user = getTeacher(announcementDto.getUserId());
CourseExecution courseExecution = getCourseExecution(announcementDto.getCourseExecutionId());
if (announcementDto.getCreationDate() == null) {
announcementDto
.setCreationDate(LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm")));
}
// Announcement has a CourseExecution as attribute
Announcement announcement = new Announcement(user, courseExecution, announcementDto);
entityManager.persist(announcement);
NotificationDto notification = NotificationsCreation.create(ADD_ANNOUNCEMENT_TITLE,
List.of(announcement.getUser().getName()), ADD_ANNOUNCEMENT_CONTENT,
List.of(announcement.getTitle(), user.getName()), Notification.Type.ANNOUNCEMENT);
this.notify(courseExecution, notification, user);
return new AnnouncementDto(announcement);
}
// Calls the Async method
private void notify(CourseExecution course, NotificationDto notification, User user) {
notificationService.notifyObservers(course, notificationService.createNotification(notification), user);
}
@Override
public void Notify(Notification notification, User user) {
for (Observer observer : this.users) { // Error occurs here, doesn't get inside the loop
if (((User) observer).getId() == user.getId()) {
continue;
}
observer.update(this, notification);
}
}
Announcement 上。而不是与其他可观察对象。因为我想要所有观察者的公告CourseExecution , 我做了 CourseExecution observable，当有新公告时，我们会通知所有 CourseExecution观察员。有人能帮助我吗？
最佳答案
我敢打赌这是数据库连接和异步的问题。数据库连接保存在本地线程中，异步方法不会在同一线程中执行，并且由于并行执行的潜力无法真正共享相同的连接/事务。您是否尝试过传播需要新的异步方法？
更有经验的成员可能能够澄清异步和未完成数据库连接的交互，但这可能是罪魁祸首。
关于java - Spring Boot Async ResultSet 已关闭，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/62560368/