Error : "No Persistence Provider for Entitymanager"

Question

I have a project in Eclipse with an application that persists in the Postgresql 9.6 database through Hibernate, but Java is not recognizing the "persistence-Unit name" which is set in the persistence.xml, even this name conferring with the name passed to the object "Entitymanagerfactory".

Below is the Exception log:

Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named bd2_persistence_unit
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:61)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
    at br.com.bd2.teste.TesteDatabase.main(TesteDatabase.java:15)

This is the code of my main:

package br.com.bd2.teste;

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

import br.com.bd2.exemplo.model.Fruteira;

public class TesteDatabase {
    public static void main(String[] args) {
        // Inicializacao da fabrica de objetos
        // persistenceUnitName = "bd2", ou seja, relaciona com a conexao na
        // persistence.xml (podera ter "n" unidades de persistencia)
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("bd2_persistence_unit");
        EntityManager em = emf.createEntityManager();

        // Os comandos a seguir devem ser executados "um por vez"
        // Inserindo...
        em.getTransaction().begin();
        em.persist(new Fruteira("Fruteira"));
        em.persist(new Fruteira("Fruteira 3"));
        em.getTransaction().commit();

        // Atualizando...
        // Buscara a fruteira com id = 1. Observe o numero do id pelo pgAdmin3!
        Fruteira fruteira = em.find(Fruteira.class, 1L); 
        if (fruteira != null) {
            em.getTransaction().begin();
            fruteira.setNome("Fruteira Legal");
            em.merge(fruteira);
            em.getTransaction().commit();
        }
        // Recuperando "n" objetos...
        TypedQuery<Fruteira> q = em.createQuery("SELECT f " +
                                                "FROM Fruteira f", Fruteira.class);
        for (Fruteira each : q.getResultList()) {
            System.out.println(each.toString());
        }       

        // Excluindo...
        // Buscara a fruteira com id = 1. Observe o numero do id pelo pgAdmin3!
        fruteira = em.find(Fruteira.class, 1L); 
        if (fruteira != null) {
            em.getTransaction().begin();
            em.remove(fruteira);
            em.getTransaction().commit();
        }

        // Recuperando "n" objetos...
        q = em.createQuery("FROM Fruteira f", Fruteira.class);
        for (Fruteira each : q.getResultList()) {
            System.out.println(each.toString());
        }

        System.exit(0);
    }
}

This is the organization of my project:

This is my Hibernate configuration xml:

     <?xml version="1.0" encoding="UTF-8"?>

    <persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
        version="2.1">


        <persistence-unit name="bd2_persistence_unit">
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> 


            <class>br.com.bd2.exemplo.model.Fruteira</class>
            <exclude-unlisted-classes>true</exclude-unlisted-classes>

            <properties>
                <property name="hibernate.connection.driver_class" value="org.postgresql.Driver" />
                <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />

                <property name="hibernate.connection.url" value="jdbc:postgresql://localhost/bd2" />
                <property name="hibernate.connection.username" value="postgres" />
                <property name="hibernate.connection.password" value="postgres" />
                <property name="hibernate.hbm2ddl.auto" value="create-drop" />
                <property name="hibernate.show_sql" value="true" />
                <property name="hibernate.format_sql" value="false" />          

                <property name="hibernate.archive.autodetection" value="true" />
            </properties>
        </persistence-unit>

    </persistence>

Answer 1

In your persistence.xml, or file you configure the persistence of Hibernate has a tag there has a name attribute.

These Names must be the same.