import java.util.Date;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateSessionFactory {

            private static final ThreadLocal threadLocal = new ThreadLocal();
            private static final SessionFactory sessionFactory;


            public static Session getSession() throws HibernateException {
        Session session = (Session)threadLocal.get();
        if (session == null || !session.isOpen()) {
            session = sessionFactory.openSession();
            threadLocal.set(session);
                }
        return session;
            }

            public static Session getNewSession() throws HibernateException {
        Session session = sessionFactory.openSession();
        return session;
            }

            public static void closeSession(Session session) {
        clearSession(session);
        session.close();
            }

            public static void closeSession() {
        Session session = getSession();
        closeSession(session);
            }

            public static void clearSession(Session session) {
        session.flush();
        session.clear();
            }

            public static void clearSession() {
        Session session = getSession();
        clearSession(session);
            }

       

            static  {
        try {
            System.out.println("-------Create the SessionFactory from hibernate.cfg.xml-------From Source Code");
            sessionFactory = (new Configuration()).configure("model/hibernate/config/hibernate.cfg.xml").buildSessionFactory();
                }
        catch (Throwable ex) {
            System.err.println("Initial SessionFactory creation failed." + ex);
            ex.printStackTrace();
            throw new ExceptionInInitializerError(ex);
                }
            }
}

getSession()

org.hibernate.SessionException: Session is closed

org.hibernate.NonUniqueObjectException