java - 回滚时取消 ejb 定时器

Question

有没有办法确保在发生异常时取消周期性(每 10 秒)和持久性计时器？ @Timeout 方法的实现是这样的(从遗留代码中简化而来):

@Timeout
@TransactionAttribute(REQUIRES_NEW)
public void onTimeout(Timer timer) {
    try {
        doSomeBusinessLogic();
    } catch (Exception e) {
        // throwing this exception makes sure rollback is triggered
        throw new EJBException(e);
    }
}

在doSomeBusinessLogic() 发生任何异常时，需要回滚其事务。这工作正常。但是，我还要确保取消计时器。

直接的解决方案是将 timer.cancel() 放在 catch block 中。然而，这是行不通的，因为取消也会被回滚(JEE6 Turorial):

An enterprise bean usually creates a timer within a transaction. If this transaction is rolled back, the timer creation also is rolled back. Similarly, if a bean cancels a timer within a transaction that gets rolled back, the timer cancellation is rolled back. In this case, the timer’s duration is reset as if the cancellation had never occurred.

如果发生异常/回滚，我如何确保取消计时器(防止任何进一步的超时)？设置最大重试次数也足够了，但我认为 JBoss 不支持这一点。

应用服务器是JBoss AS 7.2。

Answer 1

我也尝试了 Sergey 提出的解决方案，它似乎有效 - 计时器被取消。在 JBoss EAP 6.2 上测试。这是我用于测试的代码:

@Stateless
public class TimeoutTest implements TimeoutTestLocal {

@Resource
TimerService timerService;

@Resource
SessionContext sessionContext;

@Timeout
@TransactionAttribute(TransactionAttributeType.NEVER)
public void tmout(javax.ejb.Timer timer) {
    try {
        System.out.println("timout invoked");
        //instead of internal call let's invoke doNothing as
        //this timeout callback is client of TimeoutTest EJB
        //in this way doNothing will be run inside transaction
        TimeoutTestLocal local = sessionContext.getBusinessObject(TimeoutTestLocal.class);
        local.doNothing();  
    } catch (Exception e) {
        timer.cancel();
        System.out.println("Timer cancelled");
    }
}

@Override 
@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public void doNothing() {
    throw new EJBException("RE Exception");
}


@Override
public void schedule() {
    timerService.createTimer(5000, 10000, "test");
}
}