不能删除id: xxx的定时器。

Question

在GlassFish 4.1/Java 7中的单例会话bean中使用EJB计时器，如下所示。

@Singleton
@LocalBean
@Startup
public class BackgroundJobManager {

    @PersistenceContext
    private EntityManager entityManager;

    @PostConstruct
    private void init() {
        // Do something.
    }

    @Schedule(hour = "*/1", minute = "0", second = "0", persistent = false)
    public void doHourlyJob() {
        // Do something hourly.
    }

    @Schedule(hour = "*", minute = "*/1", second = "0", persistent = false)
    private void doOnEveryMinute() {
        // Do something on every minute.
    }
}

尽管日志级别是INFO，但在部署应用程序时，服务器终端上会出现以下一些不稳定的警告。

Info:   No timers to be deleted for id: 94427432094072832
Info:   No timers to be deleted for id: 94427432094072832

什么意思？它是可以避免的，还是容器试图对一些严重的问题发出警告(在这种情况下是否有任何修复)？

服务器还会在启动时记录以下行。

Info:   Portable JNDI names for EJB TimerBean: [java:global/ejb-timer-service-app/TimerBean, java:global/ejb-timer-service-app/TimerBean!org.glassfish.ejb.persistent.timer.TimerLocal]
Info:   Loading application [ejb-timer-service-app] at [/ejb-timer-service-app]
Info:   ejb.timer_service_started
Info:   ==> Restoring Timers ... 
Info:   EclipseLink, version: Eclipse Persistence Services - 2.6.0.v20150309-bf26070
Info:   /file:/C:/Program Files/glassfish-4.1/glassfish/domains/domain1/applications/ejb-timer-service-app/WEB-INF/classes/___EJB__Timer__App login successful
Info:   There are no EJB Timers owned by this server
Info:   <== ... Timers Restored.

Answer 1

这是目标IDE NetBeans (是的，不是容器GlassFish本身)中的一个怪癖，只有当在IDE上关闭“保存整个重新部署的会话”选项时才是可复制的，该选项必须在NetBeans 8.1之前完成。

​

​

(右击服务器并从子菜单中选择"property“选项似乎打开了上面的框架)。

在NetBeans 8.1之前，打开这个选项是不可能的。这样做会抛出一个exception。因此，在随后的重新部署中，会话不被维护。因此，这些消息就会出现。

这在NetBeans 8.1中不再存在。重新部署应用程序会发出以下安全消息。

Info:   keepstate options resolved to true, saving appId 95015048510636032 for application Project.
Info:   keepstate options resolved to true, saving appId 95015048510636032 for application Project.
Finer:   initialize identitymaps
Info:   Timers will not be destroyed since keepstate is true for application Project
Info:   Timers will not be destroyed since keepstate is true for application Project

因此，在重新部署期间，持久性定时器是活动的。当应用程序被重新部署时，它们不会被销毁。