no persistence provider for entitymanager named - tried everything - jpa

Question

I'm new to JPA, and i got this infamous error "no persistence provider for entitymanager named". I search far and wide on google, and tried every single solution available, to no extent i'm afraid.
Stack Trace
javax.persistence.PersistenceException: No Persistence provider for EntityManager named suplink
at javax.persistence.Persistence.createEntityManagerFactory(Unknown Source)
at javax.persistence.Persistence.createEntityManagerFactory(Unknown Source)
at com.supinfo.suplink.util.PersistenceManager.getEntityManagerFactory(PersistenceManager.java:13)
Persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="suplink" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/SupLink" />
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" />
</properties>
<class>com.supinfo.suplink.entity.User</class>
</persistence-unit>
PersistenceManager
public class PersistenceManager {
private static EntityManagerFactory emf;
private PersistenceManager() { }
public static EntityManagerFactory getEntityManagerFactory() {
if(emf == null) {
emf = Persistence.createEntityManagerFactory("suplink");
}
return emf;
}
public static void closeEntityManagerFactory() {
if(emf != null && emf.isOpen()) emf.close();
}
}
Thanks for your help :)

Answer 1

try to remove the transaction-type="RESOURCE_LOCAL"
works on my machine without this code

Answer 2

Good luck for your graded exercise, try code underneath ;)
public class PersistenceManager {
private static final EntityManagerFactory emf;
private static final ThreadLocal<EntityManager> threadLocal;
private static final Logger logger;
static {
emf = Persistence.createEntityManagerFactory("SupLink");
threadLocal = new ThreadLocal<EntityManager>();
logger = Logger.getLogger("SupLink");
logger.setLevel(Level.ALL);
}
public static EntityManager getEntityManager() {
EntityManager manager = threadLocal.get();
if (manager == null || !manager.isOpen()) {
manager = emf.createEntityManager();
threadLocal.set(manager);
}
return manager;
}
public static void closeEntityManager() {
EntityManager em = threadLocal.get();
threadLocal.set(null);
if (em != null)
em.close();
}
public static void beginTransaction() {
getEntityManager().getTransaction().begin();
}
public static void commit() {
getEntityManager().getTransaction().commit();
}
public static void rollback() {
getEntityManager().getTransaction().rollback();
}
public static Query createQuery(String query) {
return getEntityManager().createQuery(query);
}
public static void log(String info, Level level, Throwable ex) {
logger.log(level, info, ex);
}
}