Hibernate- common errors

• Mapping (RESOURCE) not found

  IDEA in, Entity of xml should be placed resources folder, and hibernate.cfg.xml corresponding mapping-resource modification

• No CurrentSessionContext configured

  Use getCurrentSession when

  • session = sessionFactory.openSession();
  • In hibernate.cfg.xml add profile

<property name="hibernate.current_session_context_class">thread</property>

• Calling method 'get' is not valid without an active transaction

  Use getCurrentSession when

  hibernate requires that all operations on the database must be open transaction management

  transaction = session.beginTransaction();

  try{

  Operation ;

  transcation.commit();

  }catch( Exception e){

  transcation.rollback();

  }

• failed to lazily initialize a collection of role

  When many mapping, the default lazy loading

  Modify loading:

  In the collection mapping at the mapping file, add the lazy properties

  Optional values:

  false : no delay in loading, disposable loading all values

  to true : ( default ) delay loading, load (can not be invoked when a specific entity size )

  Extra : automatic, load only the required information