Java tutorial
//package com.java2s; import java.math.BigInteger; public class Main { public static String encodeBigInteger(BigInteger v) { return bytesToHex(v.toByteArray()); } /** * Transformts the byte array to a * hexadecimal String * @param in byte array * @return hexstring */ public static String bytesToHex(byte[] in) { final StringBuilder builder = new StringBuilder(); for (byte b : in) { builder.append(String.format("%02x", b)); } return builder.toString(); } }