hibernate, mysql, glassfish v3, and JTA datasource
I'm attempting to use hibernate entity manager with mysql and glassfish. I'm getting the following error when attempting to use a JTA datasource:
Caused by: org.hibernate.Hibern开发者_如何学PythonateException: The chosen transaction strategy requires access to the JTA TransactionManager
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:376)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1367)
at org.hibernate.cfg.AnnotationConfiguration.buildSessionFactory(AnnotationConfiguration.java:858)
at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:733)
... 37 more
Here is how I have configured my 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="myPU" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>jdbc/mysql</jta-data-source>
<class>com.my.shared.entity.MyFile</class>
<class>com.my.shared.entity.MyRole</class>
<class>com.my.shared.entity.MyUser</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
<property name="hibernate.show.sql" value="true" />
</properties>
However, when I configure a non-jta datasource, it works fine
<?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="myPU" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<non-jta-data-source>jdbc/mysql</non-jta-data-source>
<class>com.my.shared.entity.MyFile</class>
<class>com.my.shared.entity.MyRole</class>
<class>com.my.shared.entity.MyUser</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
<property name="hibernate.show.sql" value="true" />
</properties>
</persistence-unit>
</persistence>
That's all well and good, but I would really like to use:
em.persist(myObject);
instead of:
em.getTransaction().begin();
em.persist(myObject);
em.getTransaction().commit();
Am I missing something with the hibernate configuration, or is it even possible to use a JTA datasource?
It seems like for your configuration, container-managed transactions are used by default. In this case you need to define a way of transaction synchronization so the persistence layer is notified (and can update the 2nd level cache for example). So you need to define manager_lookup_class
property as following:
// For GlassFish:
hibernate.transaction.manager_lookup_class=org.hibernate.transaction.SunONETransactionManagerLookup
// For WebSpere:
hibernate.transaction.manager_lookup_class=org.hibernate.transaction.WebSphereExtendedJTATransactionLookup
// For JBoss:
hibernate.transaction.manager_lookup_class=org.hibernate.transaction.JBossTransactionManagerLookup
// For OpenEJB:
hibernate.transaction.manager_lookup_class=org.apache.openejb.hibernate.TransactionManagerLookup
Also you have to mark business methods that access data layer as "transactional". For that you need to mark them with @javax.ejb.TransactionAttribute(REQUIRED)
(see here for more information about this annotation).
You also have an option to switch to bean-managed transactions. You can do it by saying:
hibernate.transaction.factory_class=org.hibernate.transaction.JTATransactionFactory
Then the bean is responsible for starting/ending the transaction:
org.hibernate.Session session = ...;
org.hibernate.Transaction tx = null;
try {
tx = session.beginTransaction();
session.createQuery(...); // do some staff
tx.commit();
} catch (HibernateException e)
{
if (tx != null) {
tx.rollback();
}
}
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