Start transaction in one action class and commit it on another in struts 2

Start transaction in one action class and commit it on another in struts 2

I am writting a code in an action class to insert a record in database but
not commit it at the same time as I want to commit it later after some
other record has been inserted using a different action class. I am new to
hibernate and don't know how to do this. Please, guide me. I am using
struts 2.Thanks in advance. I am using the following code in an Action to
insert a record in database without commiting
public void addExamDetails( ExamDetails examDetails){
try {
sessionFactory = new
Configuration().configure().buildSessionFactory();
session = sessionFactory.getCurrentSession();
transaction = session.beginTransaction();
session.save(examDetails);
} catch (Exception e) {
System.out.println("ExamDetailsDAO.addExamDetails()");
e.printStackTrace();
}
}
After this, in another action class I am writting the following code to
insert other record and commiting at the same time but I am not able to
commit the previous insertion
public void addExamShift( ExamShift examShift){
try {
sessionFactory = new
Configuration().configure().buildSessionFactory();
session = sessionFactory.getCurrentSession();
transaction = session.getTransaction();
transaction.begin();
session.save(examShift);
transaction.commit();
} catch (Exception e) {
System.out.println("ExamShiftDAO.addExamShift()");
e.printStackTrace();
}
}