Hello everyone!

I am a new in EJB3. I started learning with this link:

http://www.netbeans.org/kb/55/ejb30-jboss.html

I changed ma database on MySQL 4.1 and everything went ok to the moment when I added a new Session Bean for Entity Classes:

public List find_new() {
 return em.createQuery("select object(o) from Access as o where o.loginID=:a")
 .setParameter("a","1234567")
 .getResultList();

 }

I also added a line in the servlet:

list=af.find_new();

Then the JBoss server displayed this information:

java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
org.jboss.ejb3.EJBContainer.construct(EJBContainer.java:471)
org.jboss.ejb3.AbstractPool.create(AbstractPool.java:62)
org.jboss.ejb3.ThreadlocalPool.get(ThreadlocalPool.java:48)
org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:54)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:78)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:47)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:181)
org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:79)
$Proxy191.findAll(Unknown Source)
web.test.processRequest(test.java:38)
web.test.doGet(test.java:59)
javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

I don't know what this info is about?

My persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/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">
 <persistence-unit name="gogo2-ejbPU" transaction-type="JTA">
 <provider>org.hibernate.ejb.HibernatePersistence</provider>
 <jta-data-source>java:/bankingDS</jta-data-source>
 <class>ejb.Access</class>
 <class>ejb.Customer</class>
 <class>ejb.IdType</class>
 <properties>
 <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306//banking"/>
 <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
 <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
 <property name="hibernate.hbm2ddl.auto" value="update"/>
 </properties>
 </persistence-unit>
</persistence>

What's wrong, what did I miss, did I forget to add some libraries, please help.
Thanks in advance.