[b]server.log:[/b]
...
[org.hibernate.impl.SessionFactoryObjectFactory] Not binding factory to JNDI, no JNDI name configured
...
[org.jboss.hibernate.jmx.Hibernate] SessionFactory successfully built and bound into JNDI [SessionFactory]
...

[b]hibernate-service.xml:[/b]
<server>
   <mbean code="org.jboss.hibernate.jmx.Hibernate" name="jboss.har:service=Hibernate">
      <attribute name="DatasourceName">java:/DefaultDS</attribute>
      <attribute name="Dialect">org.hibernate.dialect.Oracle9Dialect</attribute>
           <property name="hibernate.default_schema">LAGERDBA</property>
      <property name="connection.pool_size">1</property>
      <property name="show_sql">true</property>
      <attribute name="SessionFactoryName">SessionFactory</attribute>
      <attribute name="CacheProviderClass">org.hibernate.cache.HashtableCacheProvider</attribute>
      <attribute name="ShowSqlEnabled">true</attribute>
   </mbean>
</server>

[b]UserManager.java[/b]
...
InitialContext ctx = new InitialContext();
SessionFactory factory;
factory = (SessionFactory) ctx.lookup("SessionFactory");
Session hsession = factory.openSession();
Transaction tx = hsession.beginTransaction();
...

[b]AcUser.java[/b]
package de.psb_gmbh.main.business.persistence.hibernate;

import java.util.Set;

public class AcUser implements java.io.Serializable {

  // Fields
  private String UserId;
  private AcGroup AcGroup;
  private String LoginName;
  private String Name;
  private String Password;
  private Integer CheckCount;
  private Set<AcUserToGroup> SetOfAcUserToGroup;

  // Constructors
  public AcUser() {
  }

  // Property accessors
  public String getUserId() {
    return this.UserId;
  }

  public void setUserId(String UserId) {
    this.UserId = UserId;
  }

  public AcGroup getAcGroup() {
    return this.AcGroup;
  }

  public void setAcGroup(AcGroup AcGroup) {
    this.AcGroup = AcGroup;
  }

  public String getLoginName() {
    return this.LoginName;
  }

  public void setLoginName(String LoginName) {
    this.LoginName = LoginName;
  }

  public String getName() {
    return this.Name;
  }

  public void setName(String Name) {
    this.Name = Name;
  }

  public String getPassword() {
    return this.Password;
  }

  public void setPassword(String Password) {
    this.Password = Password;
  }

  public Integer getCheckCount() {
    return this.CheckCount;
  }

  public void setCheckCount(Integer CheckCount) {
    this.CheckCount = CheckCount;
  }

  public Set<AcUserToGroup> getSetOfAcUserToGroup() {
    return this.SetOfAcUserToGroup;
  }

  public void setSetOfAcUserToGroup(Set<AcUserToGroup> setOfAcUserToGroup) {
    this.SetOfAcUserToGroup = setOfAcUserToGroup;
  }
}

[b]AcUser.hbm.xml[/b]
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
  <class name="de.psb_gmbh.main.business.persistence.hibernate.AcUser" table="AC_USER" schema="LAGERDBA">
    <id name="UserId">
      <column name="USER_ID"/>
      <generator class="assigned" />
    </id>
    <many-to-one name="AcGroup" class="de.psb_gmbh.main.business.persistence.hibernate.AcGroup">
      <column name="MASTER_GROUP_ID"/>
    </many-to-one>
    <property name="LoginName">
      <column name="LOGIN_NAME"/>
    </property>
    <property name="Name">
      <column name="NAME"/>
    </property>
    <property name="Password">
      <column name="PASSWORD"/>
    </property>
    <property name="CheckCount">
      <column name="CHECK_COUNT"/>
    </property>
    <set name="SetOfAcUserToGroup">
      <key>
        <column name="USER_ID" />
      </key>
      <one-to-many class="de.psb_gmbh.main.business.persistence.hibernate.AcUserToGroup" />
    </set>
  </class>
</hibernate-mapping>