Appropriate use of a servlet?

Question

I need to create a persistent Java based application that will run at set intervals. If this was strictly running under Linux I could create a CRON job but it needs to run under Windows as well. Obviously I could use some sort of service wrapper but what about using a Servlet that simply never handles any GET/POST requests? The advantage in my mind is that both Windows and Linux has Servlet containers like Tomcat (At least in my environment). One code base that works in both environments and Tomcat itself will ensure that the application runs persistently like a service.

Is this a good use of a Servlet or am I straying outside of it's intended use?

You can use pycron on Windows: http://sourceforge.net/projects/pycron/ -- it operates like cron. — Jim Ferrans, May 03 '11 at 05:01
Related: http://stackoverflow.com/questions/4691132/how-to-keep-the-servlet-continously-running — BalusC, May 03 '11 at 11:17
Not related...I'm not asking how to keep a Servlet running persistantly. My question is whether they are useful when there is no HTTP request or response needed — gshauger, May 03 '11 at 19:17

score 3 · Accepted Answer · answered May 03 '11 at 04:27

No, don't use servlets. That's not what they were designed for.

What you want is Quartz. It's a library for executing scheduled jobs. It also includes classes for integrating the scheduler with a servlet environment - once you configure it, the scheduler starts when the application is loaded and stops when it's unloaded.

score 2 · Answer 2 · answered May 03 '11 at 04:24

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The portability issue is solved almost automatically by using Java... I'd rather not use a servlet if there's no web interface.

Take a look to Quartz Scheduler framework which seems to be a perfect fit for your problem.

answered May 03 '11 at 04:24

victor hugo

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Quartz comes with a QuartzInitializerServlet to solve the problem I'm outlining. – gshauger May 03 '11 at 05:19

score 1 · Answer 3 · answered May 03 '11 at 04:40

To problem of running Quartz as a service under Windows can be addressed by using one of the many possible service wrappers; e.g.

score 0 · Answer 4 · answered May 03 '11 at 04:26

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if your application not requires container- tomcat, jsp that just use Cron trigger in your application that runs it at interval

see this example

answered May 03 '11 at 04:26

Nirmal- thInk beYond

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He just explained why he can't use Cron. – Mike Baranczak May 03 '11 at 04:35
i have given that link a example it doesnt matter if he used or not, that is just code snippet , just go that way, i assure you that it will work – Nirmal- thInk beYond May 03 '11 at 04:41
That link talks about Quartz, not Cron. – Mike Baranczak May 03 '11 at 04:44
its cron, find this on page `CronTrigger trigger = new CronTrigger(); trigger.setName("runMeJobTesting"); trigger.setCronExpression("0/30 * * * * ?");` – Nirmal- thInk beYond May 03 '11 at 04:51
Cron Trigger doesn't address my problem...QuartzInitializerServlet does though...it would seem servlets are in fact the way to go ;) – gshauger May 03 '11 at 05:19

Appropriate use of a servlet?

4 Answers4