Classloader isolation for JPA API

[danwin]

Hi All,

I need help for a class loader problem too. My error message:

the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) of the current class, oracle/toplink/essentials/internal/ejb/cmp3/EntityManagerSetupImpl, and the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) for resolved class, javax/persistence/spi/PersistenceUnitInfo, have different Class objects for the type javax/sql/DataSource used in the signature

As Dick I placed a jboss-web.xml at WEB-INF folder:

<?xml version="1.0" encoding="UTF-8" ?>
<jboss-web>
    <class-loading java2ClassLoadingCompliance="false">
      <loader-repository>
          org.jboss.classloader.spi.base:BaseClassLoader=jsfsample.war
         <loader-repository-config>java2ParentDelegation=false</loader-repository-config>
      </loader-repository>
     </class-loading>
</jboss-web>

Without result ! Then I found an article (http://nagpals.com/blog/post.cfm/classloader-conflicts-in-railo-on-jboss, I don't use railo - but anyway) that indicates to write jboss-classloader.xml for JBoss 5.X.

<?xml version="1.0" encoding="UTF-8"?>
<classloading xmlns="urn:jboss:classloading:1.0"
    name="jsfsample.war"           
    domain="jsfsample"
    export-all="NON_EMPTY"
    import-all="true">
</classloading>

Again, without result, same error.

Thx,

Daniel

[jaikiran]

Daniel Winz wrote:

Hi All,

I need help for a class loader problem too. My error message:

the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) of the current class, oracle/toplink/essentials/internal/ejb/cmp3/EntityManagerSetupImpl, and the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) for resolved class, javax/persistence/spi/PersistenceUnitInfo, have different Class objects for the type javax/sql/DataSource used in the signature

If you are packaging jars containing javax.sql.* classes and/or javax.persistence.* classes then remove those jars from the application packaging.

[danwin]

When I remove javax/sql/DataSource (i.e. removing jdbc2_0-stdext.jar) from my package I get this warning:

Starting persistence unit persistence.unit:unitName=#Employee-Details
Warning]: 2010.08.19 07:53:57.542--java.lang.NullPointerException:  null was thrown on attempt of PersistenceLoadProcessor to load class ...

Does the persistence unit not have access to the AS library?

[danwin]

I see! I don't have to remove the jdbc2_0-stdext.jar but the javax/persistence folder from the toplink-essentials.jar. 

Then I still get the NullPointerException warning. But it seams to be caused by the "temporary UCL3" classloader,  not by missing classes. I don't have a clue what this "temporary"  classloader is for, but following threads indicate to switch it off:

http://forums.oracle.com/forums/thread.jspa?threadID=584031
https://glassfish.dev.java.net/issues/show_bug.cgi?id=3721

Summerized, to switch the classloader off, I added two toplink properties to my persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="Employee-Details">
<provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
<jta-data-source>java:/jdbc/employee</jta-data-source>
<properties>
<property name="toplink.weaving" value="false"/>
<property name="toplink.logging.level" value="OFF" />          
</properties>          
</persistence-unit>
</persistence>

Deployment without errors then !