How to get 0-padded binary representation of an integer in java?

Question

for example, for 1, 2, 128, 256 the output can be (16 digits):

0000000000000001
0000000000000010
0000000010000000
0000000100000000

Answer 1

import java.util.Scanner;
public class Q3{
  public static void main(String[] args) {
    Scanner scn=new Scanner(System.in);
    System.out.println("Enter a number:");
    int num=scn.nextInt();
    int numB=Integer.parseInt(Integer.toBinaryString(num));
    String strB=String.format("%08d",numB);//makes a 8 character code
    if(num>=1 && num<=255){
     System.out.println(strB);
    }else{
        System.out.println("Number should be in range between 1 and 255");
    }
  }
}