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Singleton implemented using Servlets

jeff wisgo
Greenhorn

Joined: Apr 20, 2004
Posts: 15
I am trying to create only a single instance of a class which will run once Jakarta-Tomcat begins execution. To do this I have the following code:

*web.xml*


*InitializeController.java*


*Daemon.java*



When I run Jakarta-Tomcat, I can see the Daemon writing once every ~1 minute as expected. However, when I run other Servlets (which aren't related to this) there are additional instances of the Daemon which are apparently created, because I see many writes to the logfile, sometimes only 1 second apart. It seems like the init() function is being called again even though I t should not be.

Can anyone help out?

Thanks
[ October 01, 2004: Message edited by: jeff wisgo ]
Bear Bibeault
Author and ninkuma
Marshal

Joined: Jan 10, 2002
Posts: 61437
    
  67

I do not know what is causing your problem, but you might want to look into using context listeners to perform single-shot startup/shutdown actions rather than servlets.


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jeff wisgo
Greenhorn

Joined: Apr 20, 2004
Posts: 15
After doing some more research, it appears that the problem may be related to multiple class loaders, does anyone the semantics of how class loaders interact with Tomcat?
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: Singleton implemented using Servlets