not sure if I should search or sort my hashmap

Question

Hi I have a list of people with their ages, I need to find those who are more than 30 years old, is there any possibility to search in a hashmap ? (please note that I may need

Answer 1

HashMap hmap = new HashMap();
SortedSet keys = new TreeSet(hmap.keySet());

This will give you a sorted set which you could make a subset of.

keys.subSet(from,to) e.g keys.subSet(30,100)

and you will have a set with all required elemets.