problem using EntityManager (JDBC Driver class not found)

MistaMoasn · **Posted:** Mon Jul 04, 2005 8:43 am

hi!

i want to use hibernate, ejb3 and the entitymanager, but i got the exception displayed below. i get the exception when executing the following code in my main-method (exactly when calling createEntityMangerFactory):

Code:

   public static void main (String[] args) {
      
      // Use persistence.xml configuration
      EntityManagerFactory emf = Persistence.createEntityManagerFactory("IngresManager");
      EntityManager em = emf.createEntityManager(); // Retrieve a transactional-scoped entity manager
      //Work with the EM

      
      
      em.close();
      emf.close(); //close at application end   
   }

i know this is a simple problem, but i don't know where i have to put my jdbc-driver (= edbc.jar from ingres database) that hibernate can use it.

my folder structure is as follows:

DipasNgHibernate (Eclipse Project)
|
- src (hibernate.cfg.xml and source-files)
|
- META-INF (including persistence.xml)
- bin
- lib (with all the hibernate3 and related libs plus edbc.jar)

any hints are appreciated.

regards
patrik

my environment:
eclipse 3.1rc4, jdk1.5

Hibernate version:
3.1alpha1, the latest annotations (3.1beta3) and latest entity-manager (3.1beta1)

persistence.xml from META-INF

Code:

<?xml version="1.0" encoding="UTF-8"?>
<entity-manager>
   <name>IngresManager</name>
   <provider>org.hibernate.ejb.HibernatePersistence</provider>
   <class>ams.ingres.PvStamp</class>
   <class>ams.ingres.PvFamip</class>
   <properties>
        <property name="hibernate.connection.username">ingres</property>
        <property name="hibernate.connection.password">ingres</property>
        <property name="hibernate.dialect">org.hibernate.dialect.IngresDialect</property>
        <property name="hibernate.connection.url">jdbc:edbc://192.168.193.132:21071/dipasdem</property>
        <property name="hibernate.connection.driver_class">ca.edbc.jdbc.EdbcDriver</property>
      <property name="hibernate.hbm2ddl.auto" value="create-drop"/>
   </properties>
</entity-manager>

Full stack trace of any exception that occurs:

Code:

FATAL DriverManagerConnectionProvider:65 - JDBC Driver class not found: 
java.lang.ClassNotFoundException: 
   at java.lang.Class.forName0(Native Method)
   at java.lang.Class.forName(Unknown Source)
   at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:109)
   at org.hibernate.connection.DriverManagerConnectionProvider.configure(DriverManagerConnectionProvider.java:61)
   at org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider(ConnectionProviderFactory.java:80)
   at org.hibernate.cfg.SettingsFactory.createConnectionProvider(SettingsFactory.java:362)
   at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:60)
   at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:1429)
   at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:980)
   at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:182)
   at org.hibernate.ejb.HibernatePersistence.createFactory(HibernatePersistence.java:77)
   at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:93)
   at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:42)
   at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:29)
   at ams.hibernate.PvStampManager.main(PvStampManager.java:12)

Name and version of the database you are using:

christian · **Posted:** Mon Jul 04, 2005 9:56 am

Download CaveatEmptor and start from there: http://caveatemptor.hibernate.org/

MistaMoasn · **Posted:** Tue Jul 05, 2005 1:44 am

the caveatemptor sample mentions that i should copy my jdbc-driver into the lib-directory. i've already done that and i'm still receiving the fatal error "JDBC Driver class not found" as already described in my posting before.

what else can i try?

regards
patrik

christian · **Posted:** Tue Jul 05, 2005 4:05 am

Use HSQL DB that comes bundled with CaveatEmptor. It runs out of the box. Start from there...

MistaMoasn · **Posted:** Tue Jul 05, 2005 8:50 am

i've already tried that, it works fine, and now i want to go one step further.

i figured out that the <property name="hibernate.connection.driver_class">ca.edbc.jdbc.EdbcDriver</property> in the persistence.xml file won't work for me. this causes the fatal error (i guess).

i changed the whole properties in persistence.xml to the one following:
<property name="hibernate.ejb.cfgfile" value="hibernate.cfg.xml"/>

this link to the hibernate.cfg.xml file works in my case, but i've no idea where's the difference between the config in the persistence.xml and the hibernate.cfg.xml. they use exactly the same properties.

maybe a bug?

regards
patrik

christian · **Posted:** Tue Jul 05, 2005 8:52 am

This hasn't been finalized when the EntityManager was released. You need the CVS version to get Hibernate properties in the persistence.xml. AFAIK this still is moving and can change any day again.

MistaMoasn · **Posted:** Tue Jul 05, 2005 9:19 am

ok, good to know!
thanks for the quick response and your hints.

regards
patrik

emmanuel · **Posted:** Wed Jul 06, 2005 3:36 pm

MistaMoasn wrote:

i figured out that the <property name="hibernate.connection.driver_class">ca.edbc.jdbc.EdbcDriver</property> in the persistence.xml file won't work for me. this causes the fatal error (i guess).

This is supposed to work, even with the beta1 version. But that's true that the persistence.xml processing is a bit "fresh".