lets say that i have connections to database, mainframes, the moon etc... open.. do they remain open if i do not close them in the destroy method or do they remain in limbo until the jvm is turned off. and when does the container unload a servlet, is there a reason why it should unload the servlet. is there any way, say on tomcat that i could go and look this info up.. thanks for the quick reply..
The servlet container is not required to keep a servlet loaded for any particular period of time. A servlet instance may be kept active in a servlet container for a period of milliseconds, for the lifetime of the servlet container (which could be a number of days, months, or years), or any amount of time in between. When the servlet container determines that a servlet should be removed from service, it calls the destroy method of the Servlet interface to allow the servlet to release any resources it is using and save any persistent state. For example, the container may do this when it wants to conserve memory resources, or when it is being shut down. Before the servlet container calls the destroy method, it must allow any threads that are currently running in the service method
You will close all resources in the destryoy method (in case you have not yet closed them) else they will be lost in memory until the garbage collection occurs.