JPA: Can't find Persistence Provider

[Merrill Higginson]

I'm working through the examples in the book "Java Persistence with Hibernate". I've created a JPA probject as a Java project in Eclipse with all the necessary dependencies set up.

According to the book, one should be able to place a persistence.xml file in the META-INF directory of the classes root directory and have the Persistence class find it when it's time to build the EntityManager. However, this just does not seem to work for me. Any ideas? Below is my code:

persistence.xml in META-INF

<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
    <a href="http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"" target="_blank" rel="nofollow">http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"</a>
version="1.0">
 
<persistence-unit name="helloworld">
 
<properties>
<property name="hibernate.ejb.cfgfile"
value="/hibernate.cfg.xml" />
</properties>
</persistence-unit>
 
</persistence>

When I try to exeute the statement:

EntityManagerFactory emf = Persistence
.createEntityManagerFactory("helloworld");

I get the error:
Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named helloworld

I'm running this from Eclipse.

[Edvins Reisons]

Have you tried to specify a <provider> element for your persistence unit?

[Pierre Henry]

Hey Merrill,

In the persistence schema definition, you have the
<provider> element which indicates what persitence provider to use the DAO.
For instance:

 <provider>org.hibernate.ejb.HibernatePersistence</provider>   

to tell it you use Hibernate as the persistence framework.

That'all

[Merrill Higginson]

Thanks for your replies. I did try adding the <provider> stanza, but unfortunately, it didn't help. This problem appears to have something to do with the way applications are run inside Eclipse, because when I download the solution code and run it from an ANT task, it works fine.

[Pierre Henry]

Merrill,

Can you send a stack trace to see the origin of the problem?

[Wally Hartshorn]

Originally posted by Merrill Higginson:
Thanks for your replies. I did try adding the <provider> stanza, but unfortunately, it didn't help. This problem appears to have something to do with the way applications are run inside Eclipse, because when I download the solution code and run it from an ANT task, it works fine.

To run it from within Eclipse, you might have to place the META-INF/persistence.xml file at the root of the source (or src) directory.

[kaan acar]

I have exactly same problem. How could you solve your problem.
Thanks.

[Neil Laurance]

I had this as well.
It is because I had forgotten to place the hibernate-entitymanager.jar into my lib directory. Then when Persistence tries to find any persistence-providers on the classpath, it was not finding any at all.
Cheers, Neil

[mohammad bany yaseen]

Hi All ,


i try add a java project to use JPA persistance (not dynamic web application) i add the jar file for the entity manager but still get the same problem
here is my configrations and class files


this is the persistence.xml file under the "src" directory

<?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_1_0.xsd" version="1.0"> <persistence-unit name="test" transaction-type="RESOURCE_LOCAL"> <provider>org.hibernate.ejb.HibernatePersistence</provider> <class>model.data.Book</class> <properties> <property name="hibernate.connection.driver_class" value="org.apache.derby.jdbc.EmbeddedDriver" /> <property name="hibernate.connection.username" value="user" /> <property name="hibernate.connection.password" value="user" /> <property name="hibernate.connection.url" value="jdbc:derby://localhost:1527/HibernateDB" /> <property name="hibernate.dialect" value="org.hibernate.dialect.DerbyDialect" /> </properties> </persistence-unit> </persistence>

and the entity class manager :

package model.dao;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

public class SessionManager {
	public static EntityManager getEntityManager(){
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("test");
		return factory.createEntityManager();
	}
}

and the DAO book class

package model.dao;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;
import javax.persistence.Query;

import model.data.Book;

public class BookDao {
	public List<Book> readAllBooks(){
		EntityManager em = SessionManager.getEntityManager();
		EntityTransaction et= em.getTransaction();
		et.begin();
		Query q= em.createQuery("select b from Book b");
		List<Book> books = q.getResultList();
		et.commit();
		em.close();
		return books;
	}
}

and about the Book Entity class

package model.data;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "BOOK")
public class Book {
	@Id
	@Column( name = "isbn" )
	String isbn;
    @Column( name = "book_Name")
	String bookName;
    @Column (name="publisher_code")
	String publisherCode;
    @Column (name="publish_date")
	Date publishDate;
    @Column (name="price")
	Long price;

	/**
	 * @return the isbn
	 */
	public String getIsbn() {
		return isbn;
	}

	/**
	 * @param isbn
	 *            the isbn to set
	 */
	public void setIsbn(String isbn) {
		this.isbn = isbn;
	}

	/**
	 * @return the bookName
	 */
	public String getBookName() {
		return bookName;
	}

	/**
	 * @param bookName
	 *            the bookName to set
	 */
	public void setBookName(String bookName) {
		this.bookName = bookName;
	}

	/**
	 * @return the publisherCode
	 */
	public String getPublisherCode() {
		return publisherCode;
	}

	/**
	 * @param publisherCode
	 *            the publisherCode to set
	 */
	public void setPublisherCode(String publisherCode) {
		this.publisherCode = publisherCode;
	}

	/**
	 * @return the publishDate
	 */
	public Date getPublishDate() {
		return publishDate;
	}

	/**
	 * @param publishDate
	 *            the publishDate to set
	 */
	public void setPublishDate(Date publishDate) {
		this.publishDate = publishDate;
	}

	/**
	 * @return the price
	 */
	public Long getPrice() {
		return price;
	}

	/**
	 * * @param price the price to set
	 */
	public void setPrice(Long price) {
		this.price = price;
	}

}

when i run the following test code as java application i get the same error :

import java.util.List;

import model.dao.BookDao;
import model.data.Book;


public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		BookDao bd= new BookDao();
		List<Book> books = bd.readAllBooks();
		System.out.println(" size is "+books.size());
	}

}

best regards