org.hibernate.MappingException: Unknown entity: annotations.Users

Question

Consider the hierarchy :

And the following classes and xml :

Answer 1

Add the following code to hibernate.cfg.xml

  <property name="hibernate.c3p0.min_size">5</property>
  <property name="hibernate.c3p0.max_size">20</property>
  <property name="hibernate.c3p0.timeout">300</property>
  <property name="hibernate.c3p0.max_statements">50</property>
  <property name="hibernate.c3p0.idle_test_period">3000</property>

Answer 2

Instead of using HibernateUtil.java, to create sessionfactory object, you should use this:

SessionFactory sessionFactory=new AnnotationConfiguration().configure().buildSessionFactory();

Because in order to avoid the exception, you'll have to declare the class object in HibernateUtil.java file as configuration.addAnnotatedClass(Student_Info.class); which looks dumb because we have provided the entry already in hibernate.cfg.xml file.

To use the AnnotationConfiguration class you'll have to add a jar to your project build path: http://www.java2s.com/Code/Jar/h/Downloadhibernate353jar.htm

Answer 3

I was having same problem.

Use @javax.persistence.Entity instead of org.hibernate.annotations.Entity

Answer 4

I was having similar issue and adding

 sessionFactory.setAnnotatedClasses(User.class);

this line helped but before that I was having

sessionFactory.setPackagesToScan(new String[] { "com.rg.spring.model" });

I am not sure why that one is not working.User class is under com.rg.spring.model Please let me know how to get it working via packagesToScan method.

Answer 5

The Hibernate configuration file must define the entity classes:

<mapping class="annotations.Users"/>

Or you must explicitly add the class to the configuration using

configuration.addClass(annotations.Users.class)
// Read mappings as a application resourceName
 // addResource is for add hbml.xml files in case of declarative approach
configuration.addResource("myFile.hbm.xml");  // not hibernateAnnotations.cfg.xml

Answer 6

In my case it resolves by adding configuration.addAnnotatedClass(com.myApp.model.Example.class); after Configuration configuration = new Configuration().configure(HibernateUtil.class.getResource("/hibernate.cfg.xml")); in hibernateUtill class. It Read a mapping from the class annotation metadata . Read more about addAnnotatedClass() from here.