ClassCastException: org.apache.xerces.parsers.XIncludeAwareParserConfiguration cannot be cast to org.apache.xerces.xni.parser.XMLParserConfiguration

Question

I am developing a GWT application in Eclipse and use jdom2 to read some custom xml property files.

Following a recent update my application now fails with the above

Answer 1

I had a same exception when I upgraded my project from GWT 2.7 to GWT 2.8. I have no idea why I had not this problem with GWT 2.7 (maybe different position of in .classpath file of Eclipse project could affect it).

The reason for that exception was that before with such code like:

DocumentBuilderFactory newInstance = DocumentBuilderFactory.newInstance();
DocumentBuilder newDocumentBuilder = newInstance.newDocumentBuilder();
baseLayoutXmlDocument = newDocumentBuilder.parse( baseLayoutSvgInputStream );

SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();

the implementations from JDK package com.sun.org.apache.xerces.internal.jaxp was used, but after upgrade to GWT2.8 my app chose the xerces from gwt-dev.jar. I found the fix for that according to Javadoc and link here to used system properties

-Djavax.xml.parsers.DocumentBuilderFactory=com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl
-Djavax.xml.parsers.SAXParserFactory=com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl