What is the use of META-INF/services in the JAR and which are the Implementation classes that are picked up ?

Issue

• There are some XSLT Tranformation issues where the Transformation appear to work fine in another application server, but not in JBoss.
• Packaging the JBoss xalan.jar files for the Transformation, in the WEB-INF/lib folder.
• Need to see from where the Transformer class comes into picture. Added xalan.jar and serializer.jar to the application's WEB-INF/lib in hopes that it would pickup the needed Transformer classes, if it needed ones that were in xalan.jar versus rt.jar.