import java.util.*;      // needed for Scanner
public class InputValidation {
   public static void main(String[] args) {
	   int percentage=-1;  
	   Scanner inputScanner = new Scanner(System.in);
		do {
		   System.out.println("Enter a percentage (0-100): ");
			try {
		      percentage = inputScanner.nextInt();
				if (percentage<0 || percentage>100) {
				   System.out.println("Not a valid number.");
				}
			}
			catch (InputMismatchException e) {
			   System.out.println("Must enter an integer!");
				inputScanner.next();   // discard the bad input
			}	
		} while (percentage<0 || percentage>100);
		System.out.println("You entered " + percentage);
	}
}