Question

I am connecting a MYSQL database through hibernate and i seem to have processes that are not being killed after they are finished in the session. I have called flush and close on each session but when i check the server the last processes are still there with a sleep command. This is a new problem which i am having and was not the case yesterday. Is there any way i can ensure the killng of theses processes when i am done with a session.
Below is an example of one of my classes.

    public JSONObject check()
{
    //creates a new session needed to add elements to a database
    Session session = null;

    //holds the result of the check in the database
    JSONObject check = new JSONObject();
    try{
        //creates a new session needed to add elements to a database
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); 
        session = sessionFactory.openSession();


        if (justusername){

            //query created to select a username from user table
            String hquery = "Select username from User user Where username = ? ";

            //query created
            Query query = session.createQuery(hquery);

            //sets the username of the query the values JSONObject contents
            query.setString(0, username);

            // executes query and adds username string variable 
            String user = (String) query.uniqueResult();

            //checks to see if result is found (null if not found)
            if (user == null)
            {
                //adds false to Jobject if not found
                check.put("indatabase", "false");
            }
            else
            {
                check.put("indatabase", "true");
            }

            //adds check to Jobject to say just to check username
            check.put("justusername", true);

        }
        else
        {
            //query created to select a username and password from user table
            String hquery = "Select username from User user Where username = :user and password = :pass ";
            Query query = session.createQuery(hquery);

            query.setString("user", username);
            query.setString("pass", password);

            String user = (String) query.uniqueResult();

            if(user ==null)
            {
                check.put("indatabase", false);
            }
            else
            {
                check.put("indatabase", true);
            }

            check.put("justusername", false);

        }


        }catch(Exception e){

        System.out.println(e.getMessage());
            //logg.log(Level.WARNING, " Exception", e.getMessage());

    }finally{
    // Actual contact insertion will happen at this step

        session.flush();
        session.close();

    }
    //returns Jobject
    return check;
}

Answer 1

You should call sessionFactory.close() at the end, that will release all connections in the connection pool.

Note that normally you should have a single session factory for your whole app, which can then create as many sessions as you need. Creating the session factory is very costly.