ClassLoader error when importing or exporting BPMN diagrams with WebLogic

Compatible Application Servers

Problem

Under some circumstances, when importing or exporting a BPMN file using WebLogic, you may run into ClassLoader errors. You may get an error similar to:

ClassLoader error

JAVA

2018-05-24 10:24:25 ERROR GlobalExceptionResolver - Handler dispatch 
failed; nested exception is java.lang.LinkageError: loader constraint 
violation in interface itable initialization: when resolving method 
"org.apache.xpath.jaxp.XPathImpl.getNamespaceContext()Ljavax/xml/namespace/NamespaceContext;"
 the class loader (instance of 
weblogic/utils/classloaders/ChangeAwareClassLoader) of the current 
class, org/apache/xpath/jaxp/XPathImpl, and the class loader (instance 
of <bootloader>) for interface javax/xml/xpath/XPath have 
different Class objects for the type 
javax/xml/namespace/NamespaceContext used in the signature

org.springframework.web.util.NestedServletException: Handler dispatch 
failed; nested exception is java.lang.LinkageError: loader constraint 
violation in interface itable initialization: when resolving method 
"org.apache.xpath.jaxp.XPathImpl.getNamespaceContext()Ljavax/xml/namespace/NamespaceContext;"
 the class loader (instance of 
weblogic/utils/classloaders/ChangeAwareClassLoader) of the current 
class, org/apache/xpath/jaxp/XPathImpl, and the class loader (instance 
of <bootloader>) for interface javax/xml/xpath/XPath have 
different Class objects for the type 
javax/xml/namespace/NamespaceContext used in the signature
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1006)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)

Solution

Because of the classloader issues the following files will need to be removed from the iGrafxWebApp.war file that is located inside the EAR file:

WEB-INF/lib/stax-api.jar