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Java bean中的线程

[英]Thread in java bean

原文 2013-01-10 08:21:38 2 2 java/ multithreading/ jsp/ session/ javabeans

I have a session bean in JSP, and in that bean I am starting a thread that sleeps for 10 sec and executes again. 我在JSP中有一个会话bean，在该bean中，我正在启动一个睡眠10秒并再次执行的线程。 The problem I am facing is, after logging out also this thread continues to run. 我面临的问题是，注销后此线程也继续运行。

Can someone please help how to stop that from running? 有人可以帮忙如何阻止它运行吗？

2 个解决方案

According to the EJB specification , starting threads from EJBs is illegal. 根据EJB规范，从EJB启动线程是非法的。 Cf. cf. section 21.2.2 (page 593): 第21.2.2节（第593页）：

"The enterprise bean must not attempt to manage threads. The enterprise bean must not attempt to start, stop, suspend, or resume a thread, or to change a thread's priority or name. The enterprise bean must not attempt to manage thread groups." “企业Bean不得尝试管理线程。企业Bean不得尝试启动，停止，挂起或恢复线程，或更改线程的优先级或名称。企业Bean不得尝试管理线程组。”

There may be a different solution using EJB or you may need to use a different framework. 使用EJB可能有不同的解决方案，或者您可能需要使用不同的框架。 This depends on what exactly you are trying to accomplish. 这取决于您要完成的工作。

Starting threads out of servlets is not a good idea because you may ran out of resources (memory and CPU) if you have many users. 从servlet中启动线程不是一个好主意，因为如果您有很多用户，则可能会耗尽资源（内存和CPU）。 Especially with database access strange behaviour will occur! 尤其是使用数据库访问时，会发生奇怪的行为！

Add a Quartz timer (http://quartz-scheduler.org) that triggers every 10secs and processes a list where your session beans have beed subscribed. 添加一个Quartz计时器（http://quartz-scheduler.org），该计时器每10秒触发一次并处理一个列表，其中已订阅了您的会话bean。 On user logout unsubscribe your bean from your service again. 在用户注销时，再次取消订阅您的bean。