I am getting this error when I am running my eclipselink project.

[EL Warning]: 2008.12.05 11:47:08.056--java.lang.NoClassDefFoundError: org/jboss/resource/adapter/jdbc/ValidConnectionChecker was thrown on attempt of PersistenceLoadProcessor to load class com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker. The class is ignored.

Exception in thread "main" java.lang.NoClassDefFoundError: org/jboss/resource/adapter/jdbc/ValidConnectionChecker
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$000(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.loadClass(PersistenceUnitProcessor.java:261)
        at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.initPersistenceUnitClasses(MetadataProcessor.java:247)
        at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.processEntityMappings(MetadataProcessor.java:422)
        at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processORMetadata(PersistenceUnitProcessor.java:299)
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:830)
        at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.callPredeploy(JPAInitializer.java:101)
        at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.initPersistenceUnits(JPAInitializer.java:149)
        at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.initialize(JPAInitializer.java:135)
        at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:104)
        at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:64)
        at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
        at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)
        at Main.main(Main.java:32)
Caused by: java.lang.ClassNotFoundException: org.jboss.resource.adapter.jdbc.ValidConnectionChecker
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
        ... 24 more

Any ideas? Why would eclipselink need something from jboss? What jboss jar do I need. I would use open jpa, but for some reason after quit a few persists from my app it starts giving a bunch of stackoverflow errors.