java byte转十六进制

public static String bytes2HexString(byte[] b)

{

    String ret = "";

    for (int i = 0; i < b.length; i++)

    {

        String hex = Integer.toHexString(b[i] & 0xFF);

        if (hex.length() == 1)

        {

            hex = '0' + hex;

        }

        ret += hex;

    }

    return ret;

}

public static String toHex(byte[] buffer)

{

    StringBuffer sb = new StringBuffer(buffer.length * 2);

    for (int i = 0; i < buffer.length; i++)

    {

        sb.append(Character.forDigit((buffer[i] & 240) >> 4, 16));

        sb.append(Character.forDigit(buffer[i] & 15, 16));

    }

    return sb.toString();

}