Here you can find the source of toHex(int n)
public static String toHex(int n)
//package com.java2s; //License from project: Apache License public class Main { public static String toHex(int n) { StringBuilder sb = new StringBuilder(); if (n / 16 == 0) { return toHexUtil(n); } else {/*from w w w .j a va 2s . co m*/ String t = toHex(n / 16); int nn = n % 16; sb.append(t).append(toHexUtil(nn)); } return sb.toString(); } private static String toHexUtil(int n) { String rt = ""; switch (n) { case 10: rt += "A"; break; case 11: rt += "B"; break; case 12: rt += "C"; break; case 13: rt += "D"; break; case 14: rt += "E"; break; case 15: rt += "F"; break; default: rt += n; } return rt; } }