toHexString

 public static String toHexString(char[] letter){
        StringBuffer sbHex = new StringBuffer();
        for (int j = 0; j <letter.length; j++) {
            String hexValue = Integer.toHexString(letter[j]);
            sbHex.append(hexValue);
        }

        return sbHex.toString();
    }

    public static String toHexString(char ch){
        String hexValue = Integer.toHexString(ch);

        return hexValue;
    }

    public static String toHexString(byte b){
        String hexValue = Integer.toHexString((int)b&0xff);

        return hexValue;
    }

    public static String toHexString(byte[] letter){
        return toHexString(letter, "");
    }

    public static String toHexString(byte[] letter, String split){
        StringBuffer sbHex = new StringBuffer();
        for (int j = 0; j <letter.length; j++) {
            String hexValue = Integer.toHexString((int)letter[j]&0xff);
            sbHex.append(formatData(hexValue.toUpperCase(), RIGHT, 2, '0')+split);
        }

        return sbHex.toString();
    }