marshalling converts special characters as question marks

[ivains]

In my code I want to write some fields to an xml file.When I call \[code\]Marshaller.marshal(element, out);\[/code\] th correct fields for example a field with value= "http://stackoverflow.com/questions/15761107/bar?a" will be converted in the ByteArrayOutputStream as bar??a.Any ideas what could cause this?I have set this as properties of the marshaller:\[code\]Marshaller.JAXB_FORMATTED_OUTPUT,trueMarshaller.JAXB_ENCODING,"UTF-8"\[/code\]Thanks for the help