JPA/Hibernate: @GeneratedValue doesnt work

[Martin Dames]

Hi,

Im running into a simple issue and can not find the solution?!

I have an entity object with a technical id as primary key "BaseEntity" (its actual a superclass entity which provides the technical key for each sub-entity. Im using a Generic DAO pattern.

@Entity
@MappedSuperclass
public class BaseEntity<PK> {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private PK objectid;
...
@Entity
public class Person extends BaseEntity<Long> {
...

My Testcode looks like:

PersonDAO pDAO = new JpaPersonDAO();
Person p = new Person();
p.setFirstname("Martin");
p.setLastname("Dames");
p.setSalutation("Herr");
p.setTelephonno1("02208/910561");
pDAO.persist(p);

So, Person extends the BaseEntity above.

The persist() method throws the following exception:

Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not insert: [birthday.entities.Person]
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:226)
at birthday.dao.jpa.JpaDAO.persist(JpaDAO.java:40)
at birthday.dao.jpa.JpaDAO.persist(JpaDAO.java:1)
at birthday.test.TestDAO.main(TestDAO.java:38)

...
Caused by: java.sql.SQLIntegrityConstraintViolationException: Column 'OBJECTID' cannot accept a NULL value.
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)

So, this should not happen since the id has to be generated through hibernate/Derby.... since I used the @ID @GeneratedValue combination at the BaseEntity.

With EclipseLink as JPA Provider this works very well.... has anyone an idea what the problem is?

Thank you guys!

persistence.xml:

<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="birthday.persistence">
<!-- <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> -->
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>birthday.entities.Person</class>
<class>birthday.entities.RemindKind</class>
<class>birthday.entities.RemindIssue</class>
<properties>
<property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.EmbeddedDriver"/>
<property name="hibernate.connection.url" value="jdbc:derby:BirthdayDB;create=true"/>
<property name="hibernate.connection.username" value=""/>
<property name="hibernate.connection.password" value=""/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.show.sql" value="true"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
<property name="hibernate.archive.autodetection" value="class"/>
<property name="hibernate.current_session_context_class" value="thread"/>
<property name="hibernate.connection.pool_size" value="1"/>
<property name="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider"/>
</properties>
</persistence-unit>
</persistence>