在持久化实体时需要事务来执行此操作（使用事务或扩展持久性上下文）

Question

我正在尝试开发一个以特定间隔运行并执行一些数据库修改的类。

我设法以特定时间间隔运行的代码，从数据库中检索记录，但是当我想提交对数据库的更改时，我收到以下错误。

WFLYEE0110: Failed to run scheduled task: javax.persistence.TransactionRequiredException: WFLYJPA0060: Transaction is required to perform this operation (either use a transaction or extended persistence context)

是否允许@ApplicationScoped 创建事务？

谢谢！

@ApplicationScoped
@ActivateRequestContext
public class TaskRunner {

 @PersistenceContext(type = PersistenceContextType.EXTENDED)
  EntityManager em; 

  @Resource private ManagedScheduledExecutorService scheduler;

  private ScheduledFuture<?> TaskRunnerScheduler;

  private boolean initialized = false;

  private void init(@Observes @Initialized(ApplicationScoped.class) Object init) {

    if (initialized) return;

   
    initialized = true;
    try {
      // Execute at startup
      TaskRunner = scheduler.schedule(this::runSchedule, getSchedule());
    } catch (Throwable throwable) {

    }
  }

 @Transactional
  private void runSchedule() {
//retrieve db records
//make changes and commit
//sample
//em.persist(someEntity)
  }

  private Trigger getSchedule() {
    return new Trigger() {
      @Override
      public Date getNextRunTime(LastExecution lastExecutionInfo, Date taskScheduledTime) {
        return Date.from(
            ZonedDateTime.now().withSecond(0).withNano(0).plusHours("4").toInstant());
      }

      @Override
      public boolean skipRun(LastExecution lastExecutionInfo, Date scheduledRunTime) 
       {return false;}};
  }

}

Answer 1

事务通过拦截器启动。 当您从 bean 内部调用 bean 的方法时，方法调用不会被拦截，也不会启动任何 Transaction。

你需要另一个 Bean 并坚持在那里

@RequestScoped
@Transactional(value = TxType.REQUIRES_NEW)
public class SomeOtherBean{

    @PersistenceContext(type = PersistenceContextType.EXTENDED)
    EntityManager em;
    
    public void doSomething(){
         //retrieve db records
         //make changes and commit
         //sample
         //em.persist(someEntity)
    }
}

然后你可以在你的TaskRunner中注入那个bean

@ApplicationScoped
@ActivateRequestContext
public class TaskRunner {

    @Inject
    SomeOtherBean someBean;

    ...

    private void runSchedule() {
        someBean.doSomething()
    }

}