Hey guys, I've been beating my head against this absolutely infuriating bug for the last 48 hours, so I thought I'd finally throw in the towel and try asking here before I throw my laptop out the window.
I'm trying to parse the response XML from a call I made to AWS SimpleDB. The response is coming back on the wire just fine; for example, it may look like: <?xml version="1.0" encoding="utf-8"?> <ListDomainsResponse xmlns="http://sdb.amazonaws.com/doc/ 2009-04-15/"><ListDomainsResult><DomainName>Audio</ DomainName><DomainName>Course</ DomainName><DomainName>DocumentContents</ DomainName><DomainName>LectureSet</DomainName><DomainName>MetaData</ DomainName><DomainName>Professors</DomainName><DomainName>Tag</ DomainName></ListDomainsResult><ResponseMetadata><RequestId>42330b4a- e134-6aec-e62a-5869ac2b4575</RequestId><BoxUsage>0.0000071759</ BoxUsage></ResponseMetadata></ListDomainsResponse> I pass in this XML to a parser with XMLEventReader eventReader = xmlInputFactory.createXMLEventReader(response.getContent()); and call eventReader.nextEvent(); a bunch of times to get the data I want. Here's the bizarre part -- it works great inside the local server. The response comes in, I parse it, everyone's happy. The problem is that when I deploy the code to Google App Engine, the outgoing request still works, and the response XML seems 100% identical and correct to me, but the response fails to parse with the following exception: com.amazonaws.http.HttpClient handleResponse: Unable to unmarshall response (ParseError at [row,col]:[1,1] Message: Content is not allowed in prolog.): <?xml version="1.0" encoding="utf-8"?> <ListDomainsResponse xmlns="http://sdb.amazonaws.com/doc/ 2009-04-15/"><ListDomainsResult><DomainName>Audio</ DomainName><DomainName>Course</ DomainName><DomainName>DocumentContents</ DomainName><DomainName>LectureSet</DomainName><DomainName>MetaData</ DomainName><DomainName>Professors</DomainName><DomainName>Tag</ DomainName></ListDomainsResult><ResponseMetadata><RequestId>42330b4a- e134-6aec-e62a-5869ac2b4575</RequestId><BoxUsage>0.0000071759</ BoxUsage></ResponseMetadata></ListDomainsResponse> javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,1] Message: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(Unknown Source) at com.sun.xml.internal.stream.XMLEventReaderImpl.nextEvent(Unknown Source) at com.amazonaws.transform.StaxUnmarshallerContext.nextEvent(StaxUnmarshallerContext.java: 153) ... (rest of lines omitted) I have double, triple, quadruple checked this XML for 'invisible characters' or non-UTF8 encoded characters, etc. I looked at it byte- by-byte in an array for byte-order-marks or something of that nature. Nothing; it passes every validation test I could throw at it. Even stranger, it happens if I use a Saxon-based parser as well -- but ONLY on GAE, it always works fine in my local environment. It makes it very hard to trace the code for problems when I can only run the debugger on an environment that works perfectly (I haven't found any good way to remotely debug on GAE). Nevertheless, using the primitive means I have, I've tried a million approaches including: * XML with and without the prolog * With and without newlines * With and without the "encoding=" attribute in the prolog * Both newline styles * With and without the chunking information present in the HTTP stream And I've tried most of these in multiple combinations where it made sense they would interact -- nothing! I'm at my wit's end. Has anyone seen an issue like this before that can hopefully shed some light on it? Thanks! -Adrian -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
