[sharing time] Utils class for gist 3938993

Utils.java

/**
 *  Created by Robertof <[email protected] / http://about.me/roberto.f>.
 *  File creation date: 10-ott-2012 19.14.37
 *  Licensed under GNU/GPL v3.
 */
package com.robertof;

public class Utils {
    public static String bytesToHex(byte[] bytes) {
        final char[] hexArray = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        char[] hexChars = new char[bytes.length * 2];
        int v;
        for ( int j = 0; j < bytes.length; j++ ) {
            v = bytes[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return new String(hexChars);
    }
    
    public static byte[] hexToBytes (String hex)
    {
        int len = hex.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2)
        {
            data[i/2] = (byte) ((Character.digit(hex.charAt(i), 16) << 4)
                               + Character.digit(hex.charAt(i+1), 16));
        }
        return data;
    }
}