gnu.gcj.RawData vs. long

Hello all:

I am working to make some of our code more portable.  We "gcj-ified"
our source several years back, including making liberal use of
gnu.gcj.RawData * class members to store pointers for native (CNI)
code within object instances.

The problem is that gnu.gcj.RawData * is not portable.  The question
is: can I use "long" for the type instead without garbage collection
problems?  Can my native code store the pointer value in a Java "long"
in the CNI with impunity, or will Boehm GC think these pointers needs
to be considered for collection?

Please advise.

Thanks in advance,
Craig Vanderborgh
Voxware Incorporated