System.identityHashCode() not unique

---- From Quartz or someone ----

Bad news, go read carefuly the javadoc about System.identityHashcode(),
it doesn't garanty the unicity of it. It is more unique than hashode(), but not totally unique.

Which implies 2 design flaws:

1-
whenever an object is garbage collected, it memory address is available and his identity hashcode
(mostly implemented with memory address) will be reused. If you dispose of a xml-ized object while
more are created, the id will not be unique.

2-
the identity hashcode is certainly not unique on a 64 bit platform, with ram over 4 gigs.
the memory address is 64 bits, and 64 bit jvm will be forced to give 32 int for identity hashcode.
Even IdentityHashMap uses the generic buckets iteration whenever hashcode are ==. You must do the
same.

code piece example in converters:

public void convertAnother(Object item) {
Integer id = new Integer(System.identityHashCode(item));
if (parentObjects.contains(id))

{ throw new CircularReferenceException(); }

parentObjects.add(id);
Converter converter = converterLookup.lookupConverterForType(item.getClass());
converter.marshal(item, writer, this);
parentObjects.remove(id);
}