Exception in thread "main" org.hibernate.MappingException: Unknown entity

LinhSaysHi, I've executed your code with Hibernate 5 and I have the exact same error. I've executed it with Hibernate 4 and there is no problem.

The tutorial on Pluralsight has been created for Hibernate 4. Here is a session factory builder that works with Hibernate 5:

public class HibernateUtilities_5 {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
                    .configure("hibernate.cfg.xml").build();
            Metadata metadata = new MetadataSources(standardRegistry).getMetadataBuilder().build();
            return metadata.getSessionFactoryBuilder().build();

        } catch (HibernateException he) {
            System.out.println("Session Factory creation failure");
            throw he;
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

I also faced the same error while trying it out with Hibernate 5.1.1. But I resolved it by replacing ServiceRegistry interface with StandardServiceRegistryBuilder and used "metadatasources" to create session factory. Please see my code below

static
{
    try
    {
        //Configuration configuration = new Configuration().configure();
        standardServiceRegistry = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml")
                                    .build();
        Metadata metadata = new MetadataSources(standardServiceRegistry)
                                .getMetadataBuilder().build();
        sessionFactory = metadata.getSessionFactoryBuilder().build();

    }catch(HibernateException exception)
    {
        System.out.println("problem creating session factory!");
    }
}

public static SessionFactory getSessionFactory(){

    return sessionFactory;
}

I made these changes and it worked like a charm. please make changes in your code to the way you load the configuration file and try it again. Let me know if you still face hurdles.

Please check the schema name that you created in MySQL and the one specied in hibernate.cfg file.It was mismatching for me and i was getting same issue.

Also modify connection url like below and remove the default schema field from hibernate.cfg. jdbc:mysql://localhost:3306/protein_tracker

this worked for me.

Change the code as per Hibernate 5

    static
    {
        try {
            //Configuration configuration = new Configuration().configure();
            serviceRegistry = new 
            StandardServiceRegistryBuilder().configure("hibernate.cfg.xml")
                                        .build();
            Metadata metadata = new MetadataSources(serviceRegistry)
                                .getMetadataBuilder().build();
            sessionFactory = metadata.getSessionFactoryBuilder().build();   
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
    public static SessionFactory getSessionFactory() {
    return sessionFactory;
    }

give the give full class path in user.hbm.xml

     <class name="com.simpleprogrammer.Users" table="USERS">

map the resource in hibernate.cfg.xml

      <mapping resource="com/simpleprogrammer/Users.hbm.xml"/>

and execute the following code

    Session session = HibernateUtilities.getSessionFactory().openSession();

    session.beginTransaction();

    Users user = new Users();

    user.setuserName("Prince");
    user.setGoal(100);
    user.setId(101);
    user.setTotal(10);

    session.save(user);

    session.getTransaction().commit(); 
    session.close();
    HibernateUtilities.getSessionFactory().close();

The mapping is having a little issue. Make sure the path you specified is correct. When i had same issue, i only re-modified my mapping in the hibernate.cfg.xml to

<mapping class="com.simpleprogrammer.User"/>

Other attribute like resource were not added

I used your example and was able to get it to work with a few minor tweaks.

Verified that User.hbm.xml was located in src/main/resources/com/simpleprogrammer. Changed to lowercase table="users"

Then in hibernate.cfg.xml:

1. removed the name="" attribute from session-factory.
2. added a <property name="hibernate.connection.password">SomePassword</property>
3. added <property name="hibernate.hbm2ddl.auto">create</property>

there is problem with Hibernate jars... here i can see u are using the Hibernate 4....for developing the project... so add the hibernate 4.3.5 jar it should work.........

if u are not working with metadata than better to use hibernate 4.3 jar

The easy solution is, when you create SessionFactory object, just check your HibernateUtil class which you have created. Write correct hibernateUtility class and import correct package. If you have created multiple src packages in single project then keep packages name for hibernateutility class different.

Try this method for this problem:

1. In Entity Class use the annotations like this Annotations
2. Make Sure That FactoryConfiguration class is like this FactoryConfiguration Class

for this issue the simple solution is to make sure that, you need to update correctly in cfg.xml file 1.mapping should be done correctly as package.className. 2.Make sure you make th pojo class as @Entity

I faced the same problem what fixed my problem is I used method .addAnnotatedClass("ClassName".class) Example:

SessionFactory factory = new Configuration()
    .configure()
    .addAnnotatedClass(Students.class)
    .buildSessionFactory();

Use

Configuration.addAnnotatedClass(com.simpleprogrammer.User);