Need help Sorting a Hashtable using values??

Question

I have a hastable whose keys are unique but values are not. The problem is that i have to sort the hashtable by values.

Answer 1

You can't really sort a Hashtable by values, at least not directly. What you probably want is a way to be able to iterate through all the values contained in the Hashtable in a way that is consistent with some order defined on those values. An easy way to do this goes as follows:
Map  m;   // let that be your Hashtable
List  vals = new ArrayList(m.values());
Collections.sort(vals);  // uses the values natural order OR
Collections.sort(vals, my_comparator);  // uses the order defined by my_comparator
// this will iterate in the order defined on the values
Iterator  it = vals.iterator();
while(it.hasNext()) {
  Object val = it.next();
}