title: Testing Hibernate with JUnit: "session is closed" exception
body: <p>sometimes when testing some CRUD operations in my DAO classes using JUnit 4.5, Hibernate throws an exception:</p>
  
  <p>org.hibernate.SessionException: Session is closed!</p>
  
  <p>The session is not closed explicitly, so what happens?</p>
  
  <p>Thanks</p>