Que?

   The class Object does not define any concept of a "timestamp", and so
obviously provides no mechanism to get it.

   Your best bet is to put things into the hashmap that keep track of their
own timestamps.

   - Oliver

you look up the object with the key using HashMap.get. You then
access its timestamp field.  HashMap does not append a timestamp
object. It would have to be something you put in the object.

zee http://mindprod.com/jgloss/hashmap.html