Hi Friends, I am using Hibernate for my <b>web application..<b>

I have an exception <b>java.lang.ExceptionInInitializerError</b>
when ever i call Hibernate method to insert..

My code is very simple as shown in basic tutorials of Hibernate :
static {
try {
// Create the SessionFactory from standard (hibernate.cfg.xml)
// config file.

sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
//In above line the cause of exception
} catch (Throwable ex) {
// Log the exception.
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}

When ever I put mouse over this error it show's me like:
org.Hibernate.DuplicateMappingException

I am not getting to the problem..
Can any one help me?

org.Hibernate.DuplicateMappingException means that you defined some entity class or property twice which is not allowed.
The error lies most probably in how you mapped your persistent classes.