Problem with parser from XML to String on GWT

Hi,
I have a problem when I try parser from XML to String on GWT. In other application that it´s not GWT, I don´t have problem and I make correctly. I´m reading but I don´t find any solution.
The next code work well, but It don´t work on GWT.

-------------------------------------------------------------------------------------------
//Construction of the XML file on DOM
...

XMLSerializer xmlSerializer = new XMLSerializer();
StringWriter strWriter = new StringWriter();
OutputFormat outFormat = new OutputFormat();

outFormat.setEncoding("UTF-8");
//outFormat.setEncoding("ISO-8859-1");
outFormat.setVersion("1.0");
outFormat.setIndenting(true);

outFormat.setIndent(4);
//outFormat.setIndent(2);
outFormat.setOmitXMLDeclaration(false);

outFormat.setMethod("xml");


xmlSerializer.setOutputCharStream(strWriter);
xmlSerializer.setOutputFormat(outFormat1);
//xmlDoc es el Documento (Document) XML
xmlSerializer.serialize(xmlDoc);
strWriter.close();

//And strWriter.toString() have the xml document convert to string

-------------------------------------------------------------------------------------------

In GWT give me a mistake because I cann´t import its librery. It show the next message of mistake:

Exclude "name my class.java" from App Engine validation

Thanks

--
You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group.
To view this discussion on the web visit https://groups.google.com/d/msg/google-web-toolkit/-/zRLptuwIwrkJ.
To post to this group, send email to google-web-toolkit@googlegroups.com.
To unsubscribe from this group, send email to google-web-toolkit+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.