Class visibility problems in deployed OC4J application

Question

I have an entity, autogenerated from a database table by JDeveloper, which has the form:
Entity.java:
package a.b.c;
import ...
@Entity
@NamedQuery( ... )
@Table( ... )
public class Entity implements Serializable {
    @Column( ... )
    : etc.
}Then I have a stateless session bean, also autogenerated by JDeveloper, which has the form:
SessionEJBBean.java:
package a.b.c;
import ...
@Stateless(name="SessionEJB")
public class SessionEJBBean implements SessionEJB {
    @PersistenceContext(unitName="Simple")
    private EntityManager em;
    public List<Entity> queryFindAll() {
        return em.createNamedQuery( ... ).getResultList();
    : etc.
}Then I have my client (again, largely autogenerated):
SessionEJBClient.java:
package a.b.c;
import ...
public class SessionEJBClient {
    public static void main(String [] args) {
        try {
            final Context context = getInitialContext();
            SessionEJB sessionEJB = (SessionEJB)context.lookup("SessionEJB");
            List<Entity> entities = sessionEJB.queryFindAll();
        } catch (Exception ex) {
            ex.printStackTrace();
    private static Context getInitialContext() throws NamingException {
     : etc.
}The above code works fine, however I now want to experiment with the oracle.toplink.essentials.tools.sessionconfiguration.SessionCustomizer interface. To this end, I create a bare-bones customizer class:
Customizer.java:
package a.b.c;
import ...
public class Customizer implements SessionCustomizer {
    public Customizer() {
    public void customize(Session session) {
}and make corresponding updates to the persistence.xml file:
persistence.xml:
<?xml version="1.0" encoding="windows-1252" ?>
<persistence
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
  http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
  version="1.0" xmlns="http://java.sun.com/xml/ns/persistence">
  <persistence-unit name="Simple">
    <properties>
      <property name="toplink.session.customizer" value="a.b.c.Customizer"/>
    </properties>
  </persistence-unit>
</persistence>Now, when I redeploy and attempt to run my client application, I'm told that the customizer class cannot be found:
11-Jun-2007 16:32:17 oracle.j2ee.rmi.RMIMessages
EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER
WARNING: Exception returned by remote server: {0}
javax.ejb.EJBException: Exception [TOPLINK-28006]
(Oracle TopLink Essentials - 2006.8 (Build 060829)):
oracle.toplink.essentials.exceptions.EntityManagerSetupException
Exception Description: ClassNotFound: [a.b.c.Customizer]
specified in [toplink.session.customizer] property.
Internal Exception: oracle.classloader.util.AnnotatedClassNotFoundException:
       Missing class: com.logicacmg.security.Customizer
     Dependent class: oracle.toplink.essentials.internal.security.PrivilegedAccessHelper
              Loader: oracle.persistence:1.0
         Code-Source: /usr/oc4j/toplink/jlib/toplink-essentials.jar
       Configuration: <code-source> in /usr/oc4j/j2ee/home/config/server.xml
This load was initiated at oracle.persistence:1.0 using the Class.forName() method.
The missing class is available from the following locations:
     1. Code-Source: /usr/oc4j/j2ee/home/applications/SimpleApp/SimpleApp.jar
(from <ejb> in /usr/oc4j/j2ee/home/applications/SimpleApp)
        This code-source is available in loader SimpleApp.root:0.0.0.
This is the current thread's context loader, and it appears that Class.forName()
was used to load the dependent class. If a loader was not explicitly passed to
Class.forName(), try passing the result of calling
Thread.currentThread().getContextClassLoader()So, my question is: what is the correct way for me to configure the system so that my Customizer class is picked up?
Apologies if this is obvious - I'm still rather new to working in this area (so if anything else I've written doesn't make sense - please don't be afraid to point it out!).
Regards,
Alistair.

Answer 1

Hi, you all seem highly intelligent so I'll give this a shot.
We're having a similar problem, but TopLink is not involved. Axis2 is, but in our case, the Axis2 application runs fine, it's the other applications that fail.
We have three applications, Login, Candle, and Webservices (the one with Axis2). When we first start up the applications, they all instantiate fine. We can run Login pages and Candle pages fine. We can also run non-Axis2 Webservices servlets without breaking Login and Candle. But when we run a webservices servlet that uses Axis2, something happens that causes all future Login and Candle class loading to fail! From the error message, OC4J indicates that it is trying to load classes for Login and Candle using the classloader for Webservices.
So, to summarize, once the webservices app runs an Axis2 servlet, OC4J tries to use the webservices' classloader to load classes for the other applications instead of using their classloaders. The example error message I give below is for the Candle application, but the same problem occurs for Login.
Please help, even if it's just a suggestion for something to try!! We've been trying to understand this for 2 days and we're still as stumped as ever.
[java] 2007-06-15 14:59:59,159 ERROR [org.apache.struts.action.RequestProcessor] - No action instance for path /adpThrowableHandler could be created
[java] oracle.classloader.util.AnnotatedClassNotFoundException:
[java] Missing class: com.adp.candle.core.ui.struts.exceptionhandler.AdpThrowableHandlerAction
[java] Dependent class: org.apache.struts.util.RequestUtils
[java] Loader: default.web.candle:0.0.0
[java] Code-Source: /C:/build/javaroot/candle/WEB-INF/lib/struts.jar
[java] Configuration: WEB-INF/lib/ directory in C:\build\javaroot\candle\WEB-INF\lib
[java] This load was initiated at default.web.webservices:0.0.0 using the loadClass() method.
[java] The missing class is available from the following locations:
[java] 1. Code-Source: /C:/build/javaroot/candle/WEB-INF/classes/ (from WEB-INF/classes/ in C:\build\javaroot\candle\WEB-INF\classes)
[java] This code-source is available in loader default.web.candle:0.0.0.
-- Brad