JAXB in jBPM

[hauch]

I'm trying to use JAXB in jBPM, which produces the error mentioned in https://jira.jboss.org/jira/browse/JBPM-1404.
I have downloaded the source code and tried to apply the patch described in the jira by replacing only the class and the inner classes.
Unfortunately I am not able to get it to work.
I am using the jBPM bundled with JBoss ESB 4.4, and I have downloaded and patched jpdl-3.2.2-SOA-4.2 from subversion.

The findClass in ProcessClassLoader now looks like:

public Class findClass(String name) throws ClassNotFoundException {
 Class clazz = null;

 FileDefinition fileDefinition = processDefinition.getFileDefinition();
 if (fileDefinition!=null) {
 String fileName = "classes/" + name.replace( '.', '/' ) + ".class";
 byte[] classBytes;
 try {
 classBytes = fileDefinition.getBytes(fileName);
 clazz = defineClass(name, classBytes, 0, classBytes.length);
 } catch (JbpmException e) {
 clazz = null;
 }
 // Add the package information
 final int packageIndex = name.lastIndexOf('.') ;
 if (packageIndex != -1) {
 final String packageName = name.substring(0, packageIndex) ;
 final Package classPackage = getPackage(packageName) ;
 if (classPackage == null) {
 definePackage(packageName, null, null, null, null, null, null, null) ;
 }
 System.out.println("package is: "+packageName);
 }
 }

 if (clazz==null) {
 throw new ClassNotFoundException("class '"+name+"' could not be found by the process classloader");
 }

 return clazz;
 }

- and the output is:
20:14:04,030 INFO [STDOUT] package is: dk.lenio.em.smile.jbpm.vo
20:14:04,063 ERROR [GraphElement] action threw exception: "dk.lenio.em.smile.jbpm.vo" doesnt contain ObjectFactory.class or jaxb.index
javax.xml.bind.JAXBException: "dk.lenio.em.smile.jbpm.vo" doesnt contain ObjectFactory.class or jaxb.index

I have a class named ObjectFactory in the package dk.lenio.em.smile.jbpm.vo.

Any suggestions?

[kukeltje]

with all these kinds of new reflection using frameworks with custom classloader things, the processclassloader (used for versioning mainly) becomes less and less usefull (imo).

So my suggestion would be to try it without loading any classes that are in the processarchive. Put all in jars on the classpath but jou might run into https://jira.jboss.org/jira/browse/JBPM-1148 then....

[hauch]

Thanks for your reply.
I'm not to happy about the suggestion, however.
That would require a restart with every change in objects (internal to jbpm) - and might cause problems if a class used in a long running workflow changes.

[kukeltje]

Yep... correct... but my suggestion was just to check if it works then, so we have a more narrow path to search for the real problem... and maybe rethink (redesign?) the class versioning in relation to processdefinitions

[hauch]

Fair enough...

So I did as suggested: copied my objects using jaxb to lib, which worked fine.
This is however an unacceptable solution (as mentioned above), and the only purpose was to narrow down the problem.

So back to start: any suggestions how to make jaxb work with classes loaded with the jbpm classloader?

[kukeltje]

Hauch,

I think the first thing to do is to make a jira issue for this. This does not solve your problem, I know, but it puts it on the radar. A complete yet simple example would help a lot.

This is such a fundamental thing (the classloader in relation to other frameworks) that I suspect that you will not get any help from the community. Not that they do not want to, but for some that had kind of similar issues, it was not a big deal to do it differently. The core developers are the ones that can either help you with some suggestions, fix it or whatever.

Sorry

[hauch]

Ronald

Thanks for your help.
There is already a jira on this issue - I just couldn't get the described fix to work (see the first post).
My hope was that somebody actually had tried the fix, and was able to help me.

I will find another way to solve the problem (probably using xStream, xmlBeans or equivalent).