Control the hibernate session(when to close it manually)

Question

I am new in hibernate,after read the hibernate api and tutorial,it seems that the session should closed when not used.

Like this:

Session sess=getSe         


        

Answer 1

We can make use of ThreadLocal.

public class MyUtil {
private static SessionFactory sessionFactory;
private static ServiceRegistry serviceRegistry;
private static final ThreadLocal threadLocal;

static {
try {
    Configuration configuration = new Configuration();
    configuration.configure();
    serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
    sessionFactory = configuration.buildSessionFactory(serviceRegistry);
    threadLocal = new ThreadLocal();

    } catch(Throwable t){
      t.printStackTrace();
      throw new ExceptionInInitializerError(t);
    }
}
public static Session getSession() {
    Session session = threadLocal.get();
    if(session == null){
        session = sessionFactory.openSession();
        threadLocal.set(session);
    }
    return session;
}

public static void closeSession() {
    Session session = threadLocal.get();
    if(session != null){
    session.close();
    threadLocal.set(null);
    }
}

public static void closeSessionFactory() {
    sessionFactory.close();
    StandardServiceRegistryBuilder.destroy(serviceRegistry);
   }
}

Here, the SessionFactory is initialized only once using the static block. Hence, whenever the main class makes a call to getSession(), the presence of Session object is first checked in the threadLocal object. Therefore, this program provides thread-safety. After each operation, closeSession() will close the session and set the threadLocal object to null. Finally call the closeSessionFactory().