Avoid a class to be garbage collected

[Perez Guerrero, Antonio Javier]

Hi,
 
Is there any way I can "bind" a class with Cocoon, or make it persistent, so 
it's never destroyed by the garbage collector?
 
I've a singleton class containing some data structures (basically Maps), which 
need to be shared between users (so, I can't store them in session). I could 
write the data to a XML file, but I'd really prefer to avoid it, because the 
data is going to change very frecuently.
 
Thanks