https://issues.apache.org/bugzilla/show_bug.cgi?id=48214
--- Comment #2 from Mark Thomas <ma...@apache.org> 2009-12-21 06:13:16 GMT --- The problem you are seeing is a result of where you have placed the driver class, how DriverManager works internally and what Tomcat now does to prevent memory leaks. Your driver class is in CATALINA_HOME/lib so will be loaded by Tomcat's common class loader. The sequence of events is: - Tomcat starts - Your app starts - Your servlet is loaded and init() runs - The driver class is loaded due to the Class.forName() call - The common class loader loads the class - The class is registered with DriverManager but as DriverManager uses the context class loader, it is registered against your web application - The app runs for a while - The app is reloaded - Tomcat spots that DriverManager has registered the JDBC driver against the webapp class loader - Tomcat unregisters the JDBC driver to prevent a memory leak - Your app restarts - Your servlet is loaded and init() runs - The driver class is not loaded since it was loaded by the common class loader and is, therefore, still available - No class is loaded, so no driver is registered with DriverManager - init() fails when DriverManager can't find the driver There are many ways to fix this. The simplest are: - use a context listener to explicitly call DriverManager.register and deregister() - move the JDBC driver to WEB-INF/lib Tomcat 7 logs a message when unregistering the JDBC driver that provides a useful clue as to what is going on. Tomcat 6 doesn't do that. I'll propose the necessary changes for inclusion in Tomcat 6. -- Configure bugmail: https://issues.apache.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
