I. 1 am using Hibernate in my DAO layer to get data from MySQL and
using HQL query every thing is going fine.

2. And i am using core jdbc statements on connections getting from
hibernate session in some other classes of my application.

But i am getting the error "No operations allowed after statement closed"
in class where i am using HQL query (in code mentioned in case 1) even
though i am not using any jdbc statement in this class ?

Can anybody please explain me the reason behind this problem and
give me the possible solution ?

and How the hibernate uses jdbc statement internally to execute HQL query ?