Re: Life of static variables within the VM

java400-l-bounces@xxxxxxxxxxxx wrote on 10/20/2006 10:13:45 AM:

I have a question regarding the life of static variables within the VM.
I always thought that if you instantiated an object that contained
static variables, garbage collection would cleanup the object along with
the static variables.  For instance, say I have classes Pet and Cat.
Cat contains several static variables (say names of cats) and I
instantiate an instance of Cat from Pet.  Do the static variables within
Cat ever get GC'd.  This is something I obviously missed a long time ago
and feel a little sheepish for not knowing.

Static fields are stored in their class object (instance of
java.lang.Class)
and classes are only GC'd when their loading classloader is GC'd.

So, if Cat is loaded by the same classloader as Pet, then the class Cat
will
survive as long as the class Pet does.

A tangential question: why static fields?  A real "Cat" object would have
the 'name' as an instance field, eh?  Just a thought...

-blair