Is a particular value in(exist) Set

 
import java.util.Set;
import java.util.TreeSet;

public class Main {
  public static void main(String[] args) {
    Set<String> tSet = new TreeSet<String>();
    tSet.add("1");
    tSet.add("2");
    tSet.add("3");
    tSet.add("4");
    tSet.add("5");

    boolean blnExists = tSet.contains("3");
    System.out.println("3 exists in TreeSet ? : " + blnExists);
  }
}