How to fix an invalid XML so it can be consumed by Spring WebServiceTemplate

I'm using Spring's WebServiceTemplate to consume a Soap service. Once in a while this Soap service responds with an invalid XML. I would like to intercept its parser and fix the invalid XML before it is parsed. How could I do that? Right now I'm calling:

wsTemplate.sendSourceAndReceiveToResult(new StreamSource(new StringInputStream(msg)),new StreamResult(stringWriter))

I suppose I have to call sendSourceAndReceive and define my own SourceExtractor but that seems like I'm meddling too much on the process when I actually wanted to do something simple.

This is the problem I want to fix:

An invalid XML character (Unicode: 0x1f) was found in the element content of the document.

SystemErr     R    at org.springframework.ws.soap.saaj.SaajSoapMessageFactory.createWebServiceMessage(SaajSoapMessageFactory.java :210)

That character is accepted in XML 1.1 but the document is described as XML 1.0:

<?xml version="1.0" encoding="utf-8"?>

So what I want is to replace that character for a tab or a space.

Solution

I was able to fix the message before it's parsed by decorating the webServiceTemplate's WebServiceMessageFactory as follows:

final WebServiceMessageFactory mfOriginal = myWebServiceTemplate.getMessageFactory();
WebServiceMessageFactory mfDecorator = new WebServiceMessageFactory() {
    @Override
    public WebServiceMessage createWebServiceMessage(final InputStream inputStream) throws InvalidXmlException, IOException {
        InputStream decoratedIs = new InputStream() {

            @Override
            public int read() throws IOException {
                int nextByte = inputStream.read();
                // Replacing the invalid character with a tab. Touching nothing else.
                if (nextByte == 0x1f) {
                    nextByte = 0x09;
                }
                return nextByte;
            }
        };
        return mfOriginal.createWebServiceMessage(decoratedIs);
    }

    @Override
    public WebServiceMessage createWebServiceMessage() {
        return mfOriginal.createWebServiceMessage();
    }
};
myServiceTemplate.setMessageFactory(mfDecorator);