Re: destroy() method V.S. finalize() method

[Fred Kulack <kulack@xxxxxxxxxx>]

On 11/14/2002 at 03:05:33 PM, java400-l-admin@midrange.com wrote:
An object gets destroyed (garbage collected) only when there is no
reference
to it.  When one stores an object into a Map, the Map has a reference to
it.
To destroy this object one has to remove this entry from Map in addition to
setting other references to null.
--- end of excerpt ---

Actually, from a Java language standpoint, thats not quite complete.
Objects may conceivably never be garbage collected.
The object gets destroyed when there is no reference to it AND the JVM
needs more
memory (because its currently out) and/or decides to garbage collect it for
other reasons.

1) A close() or destroy() method is typical model for what you want to do.
When the user calls close() or destroy(), take your action.
2) Also take your action in the finalize() method in case the user leaks
the object
3) The weak reference would be a good mechanism to allow the garbage
collector
to claim your object (and you'd put some code in to detect it), but you
still probably
want #1 and #2 in that case anyway.



"The stuff we call "software" is not like anything that human society
  is used to thinking about. Software is something like a machine, and
  something like mathematics, and something like language, and
  something like thought, and art, and information...
  but software is not in fact any of those other things."
Bruce Sterling - The Hacker Crackdown

Fred A. Kulack - IBM eServer iSeries - Enterprise Application Solutions
ERP, Java DB2 access, Jdbc, JTA, etc...
IBM in Rochester, MN  (Phone: 507.253.5982   T/L 553-5982)
mailto:kulack@us.ibm.com   Personal: mailto:kulack@magnaspeed.net
AIM Home:FKulack  AIM Work:FKulackWrk
MSN Work: fakulack@hotmail.com