import java.util.Collections; import java.util.HashSet; public class Main { public static void main(String[] args) { HashSet<Long> hashSet = new HashSet<Long>(); hashSet.add(new Long("9")); hashSet.add(new Long("4")); hashSet.add(new Long("2")); hashSet.add(new Long("2")); hashSet.add(new Long("3")); Object obj = Collections.min(hashSet); System.out.println("Minimum Element of HashSet is : " + obj); } }