This example uses non-standard classes in the sun.misc package to convert to and from Base64. These classes may change in the future. 
    try {
        // Convert a byte array to base64 string
        byte[] buf = new byte[]{0x12, 0x23};
        String s = new sun.misc.BASE64Encoder().encode(buf);
    
        // Convert base64 string to a byte array
        buf = new sun.misc.BASE64Decoder().decodeBuffer(s);
    } catch (IOException e) {
    }