Java tutorial
//package com.java2s; public class Main { /** * Zero pad a number to a specified length * * @param buffer buffer to use for padding * @param value the integer value to pad if necessary. * @param length the length of the string we should zero pad */ private static void padInt(StringBuilder buffer, int value, int length) { String strValue = Integer.toString(value); for (int i = length - strValue.length(); i > 0; i--) { buffer.append('0'); } buffer.append(strValue); } }