Aucun fournisseur de Persistance pour l'EntityManager nommé X

Je suis en train d'élaborer un JavaSE application utilisant JPA. Malheureusement, je me null après l'appel:
Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);

Ci-dessous vous trouverez:

• Un extrait de mon code qui appelle EntityManagerFactory et inattendue renvoie null
• Mon persistence.xml fichier
• Mon projet de structure

Extrait de mon code:

public class Main {
    private static final String PERSISTENCE_UNIT_NAME = "MeineJpaPU";
    private static EntityManagerFactory factory;

    public static void main(String[] args) {
        //I get null on this line!!!
       factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);

       EntityManager em = factory.createEntityManager();
       //do stuff with entity manager
       ...
    }
}

Mon 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="MeineJpaPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
    <class>path.to.package.server.Todo</class>
      <exclude-unlisted-classes>false</exclude-unlisted-classes>
     <properties>       
            <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>       
            <property name="javax.persistence.jdbc.url"  value="jdbc:postgresql://localhost:5432/test"/>       
            <property name="javax.persistence.jdbc.user" value="postgres"/>       
            <property name="javax.persistence.jdbc.password" value="postgres"/>       
        </properties>
  </persistence-unit>
</persistence>

Mon projet structure:

OriginalL'auteur joshi737 | 2013-10-11