Retrieve the key from a map (2)

Sorry to everyone,

probably I simplified my example a bit too much. So here is what I
really want;

I want to implement a cache, where the key class is implemented by
myself, but the value class is java.util.List. I want to count the hits
of this cache, separately for each cache entry. Therefore I want to
store the hits-counter at the key class.

class Key
{
  Object value;
  int hits;

  int hashCode()
  {
     return value.hashCode();
  }

  boolean equals(Object o)
  {
     return (o instanceof Key) && value.equals(((Key)o).value);
  }
}

class Cache
{
  HashMap<Key, List> store = new HashMap<Key, List>()

  void put(Key key, List value)
  {
     store.put(key, value);
  }

  List get(Key key)
  {
     Key originalKey = store.getKey(key) // does not exist !!!!!!
     if(originalKey!=null)
        originalKey.hits++;
     return store.get(key);
  }
}

As you can see, for the hit counter to work, I need the same (not just
equal) key, that was used for insertion into the map. I don't know how
to do this - apart from the obvious brute force attack.

Ralf.