Help with error : Class X violates loader constraints

[joao.clemente]

Hi! I get this error when running a servlet/ejb program that I wrote, but I don't know what this means, or from where does it comes from.

----- Error sample here ---------

java.lang.LinkageError: Class web/Subscribe/SubscribeBean violates loader constraints at web.Subscribe.SubscribeServlet.processRequest(SubscribeServlet.java:84)

---------------------------------


I had the same example running in a Sun J2ee implementation, with the aid of the sun deployment tool, that writes the web.xml, apllication.xml and propryetary sun j2e xml file. It ran without a problem.

Then I tryed to deploy it in JBoss, and I've done (or tried to) a jboss.xml that would reflect the same things that were in the sun's xml file...

At this time I'm not sure if the error I'm getting can be simply by a badly made jboss.xml or not...

Any help or comments? Thank you.

Joao Clemente
Computer Science - IST - Portugal

[jasonbrome]

Hi,

I'm experiencing this exception as well. Today I started to test with the v2.4.4 (Tomcat 4.0.1) release. I took my .ear that works perfectly with JBoss 2.4.4 / Tomcat 3.2.3, and am now experiencing issues with this new release.

It seems to be a Class Loader related issue - the class in my app that is reported as violating loader constraints is a Value Object class, an instance of which is returned from a Session Bean method. I've read elsewhere that there maybe potential packaging/scope issues related to this, and I was wondering if anybody has any guidelines?

Thanks,

Jason

[joao.clemente]

You mean that this may be a problem with the code itself? And not with the deployment?

I haven't still solved the issue I'm having and I think I'll try with the bundel with the older Tomcat version to see if it works there...

[jasonbrome]

I'm not sure what is the cause of the problem, but it seems that there is a difference in class loading behavior between the Tomcat 3.2.3 package and the Tomcat 4.0.1 package - can anyone else shed any light on this?

Thanks

Jason

[joao.clemente]

One other strange thing :

I've now reverted to using JBoss+Tomcat3.x , and with the app I was trying to deploy (that originated this thread) I don't get the error I was getting with Tomcat4 ...

However, one other app I was running fine in Tomcat4 doesn't deploy in tomcat3.x .. weird ...

I have looked a bit through Tomcat's homepage trying to find out if they had a report on diferences between the two versions but found nothing...

[cs710]

I had the same problem. Everything runs well on Solaris, but gets the problem on Linux. Any update?

[jkrause]

I get the same error when I update a class in a EJB jar file then jar/upload it to the JBoss server. When debugging a problem, I have to frequenty upload the changed EJB jar files to the jboss server folder, overwriting the old ones then have the server auto-reload it. When my jsp tries to load the EJB again, I get this error. However if I kill JBoss server and restart it, not changing anything, the new classes load without error.

Its just annoying to have to reload JBoss every time I make a change to a EJB class in a Jar file. I used to not have to do that.