provider tag in persistence.xml

[Christophe Verré]

I was trying to make a sample using Spring3 and JPA2. The persistence provider is Hibernate.
It might be a Spring-related issue, but I'm not sure, so I ask here first.

My persistence.xml was looking like this :

<?xml version="1.0" encoding="UTF-8"?>
<persistence 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_2_0.xsd"
        version="2.0">

    <persistence-unit name="galleryPersistenceUnit" />
</persistence>

I was getting the following error :

Caused by: java.lang.IllegalArgumentException: No PersistenceProvider specified in EntityManagerFactory configuration, and chosen PersistenceUnitInfo does not specify a provider class name either
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:207)
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:308)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)

I solved it by adding the provider tag in persistence.xml :

<?xml version="1.0" encoding="UTF-8"?>
<persistence 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_2_0.xsd"
        version="2.0">

    <persistence-unit name="galleryPersistenceUnit">
         <provider>org.hibernate.ejb.HibernatePersistence</provider>
    </persistence-unit>
</persistence>

Why doesn't it work without the provider tag ? The hibernate documentation says:

The provider is a fully-qualified class name of the EJB Persistence provider. You do not have to define it if you don't work with several EJB3 implementations. This is needed when you are using multiple vendor implementations of EJB Persistence.

.
I'm using a standalone application, so I don't think that I need to set the provider tag. Or could it be that I have several providers on my classpath ?

[Matt Kirk]

Hi Christophe,

Did you ever get an answer on this topic?

Thanks,
Matt