I am working on a web application using hibernate and spring. We are using spring for managing transactions. Our application uses native queries heavily along with Hibernate queries. Below is code in a DAO how we execute it:

Session hibernateSession = getSession();
myList = hibernateSession.createSQLQuery(query).list();
hibernateSession.flush();
hibernateSession.close();

As shown in above code every time the query executes new session is created and hence separate connection is obtained for each call. This makes number of busy connections jumps to maximum pool size. With this and new incoming request are not entertained with exception failed to check out connection from pool.

Using the sessionFactory.getCurrentSession() throws exception "No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here"

are you creating new session in your getSession method or retrieving the already open session

code calls getSession() from HibernateDaoSupport.clas and always create new session.

I am looking is it possible to use existing session just like Spring do for whole request instead of for each method call.

i have no idea about spring but it is possible to reuse the hibernate session,depends how u r using it
i use session per transaction rather session per request

Ok could you give bit more details. If a transaction require multiple DAO method calls and native queries how you use all these under single transaction.

//Open your session
Session sess=...............;
Transaction trans=s.beginTransaction();
//call your dao method
//if u r passing session
daoMethod(....,sess);


//in dao simply get the session check whether transaction is active execute native queries


trans.commit();