Called before the object's memory is reclaimed by the VM. This
can only happen once the garbage collector has detected that the
object is no longer reachable by any thread of the
running application.
The method can be used to free system resources or perform other cleanup
before the object is garbage collected. The default implementation of the
method is empty, which is also expected by the VM, but subclasses can
override finalize()
as required. Uncaught exceptions which are
thrown during the execution of this method cause it to terminate
immediately but are otherwise ignored.
Note that the VM does guarantee that finalize()
is called at most
once for any object, but it doesn't guarantee when (if at all) finalize()
will be called. For example, object B's finalize()
can delay the execution of object A's finalize()
method and
therefore it can delay the reclamation of A's memory. To be safe, use a
ReferenceQueue
, because it provides more control
over the way the VM deals with references during garbage collection.