Below program illustrates how to reverse an Integer in Java:
public class ReverseInteger { public static void main(String[] args) { int num = 12345; int result = reverse(num); System.out.println(result); } private static int reverse(int n) { int result = 0; while (n > 0) { int rem = n % 10; n = n / 10; result = (result * 10) + rem; } return result; } }