Connection getting closed automatically

I have written an web application and deployed in tomcat. I am using simple pojo java beans to access the database connection in my jsps. The problem is after some time (30-45 mts) if no activity is done on this application I am getting the null pointer exception. I suspect that the connection with the database is getting closed.

Will the database (mysql) automatically get closed in java?

[404 byte] By [RYALIa] at [2007-11-26 16:08:44]