Logging a ByteBuffer value, but now I want to get the original String (an XML) from that ByteBuffer

Asked Jun 26 '16 at 01:10

Active Jun 26 '16 at 01:15

Viewed 190 times

How can I do that?

I tried this:

        String a = "my_byte_buffer_copied_from_my_logs";
        value = ByteBuffer.wrap(a.getBytes(StandardCharsets.UTF_8)); 

        InputStream callbackRequest = new ByteArrayInputStream(value.array());    
        return jaxbContext.createUnmarshaller().unmarshal(callbackRequest);

But it fails with this message:

org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.

Which seems to indicate that the XML is not valid

FYI, I know that the encoding UTF-8 is correct.

edited May 23 '17 at 12:22

Community

asked Jun 26 '16 at 01:10

Cacho Santa

6,846
6
41
73

2

Do you have a BOM? – Sotirios Delimanolis Jun 26 '16 at 07:39
How can I know if I have a BOM or not? Because the XML is represented as a ByteBuffer (which is then logged as a string). The value starts with 'PD94' then I have like 400 bytes and it ends with 'bnQ+'..... @SotiriosDelimanolis – Cacho Santa Jul 04 '16 at 23:02
Check for the corresponding bytes at the beginning of the buffer. https://en.wikipedia.org/wiki/Byte_order_mark – Sotirios Delimanolis Jul 04 '16 at 23:06
I don't think I have it, according to the wiki, the BOM should be "EF BB BF" in hex.... @SotiriosDelimanolis – Cacho Santa Jul 04 '16 at 23:19
What are the first 3 bytes in the buffer? – Sotirios Delimanolis Jul 04 '16 at 23:25
'504' @SotiriosDelimanolis in hex, but the String value is 'PD9' – Cacho Santa Jul 04 '16 at 23:26
I don't understand that representation. Are you saying the first three bytes are 5, 0, and 4? Please show us how you're determining that. There's no byte value 504. – Sotirios Delimanolis Jul 04 '16 at 23:29
I did an 'xxd file' and the first line 0000000: 5044 3934 6257 7767 646d 5679 6332 6c76 @SotiriosDelimanolis – Cacho Santa Jul 04 '16 at 23:56
That doesn't look like XML to me. You obviously aren't receiving what you expected. – Sotirios Delimanolis Jul 05 '16 at 19:46

Logging a ByteBuffer value, but now I want to get the original String (an XML) from that ByteBuffer

0 Answers0