Hi
i am a newbie to the hibernate
Can you explain me what is the need
of to open the session in the view

is n't it a bad design pattern

why not we close the session in our controller class
but before close the session
we store all the data in a collection
and set that collection in the request scope
then show the data in the view

after open the session in the view
then get the object from the session
is n't we trying to access the database entity
in our view

here where is the MVC pattern

i am confuse
please help me

Well, open session in view allows you to access the data you need, when you need it. Otherwise, you need to anticipate all of the data your view will need, and then close the session. Having the back end try and figure out the needs of the front end IS a bad design.

Open session in view is very efficient.

Hi
thanks for your reply
but i have to ask another question

suppose we use the open session in 50 view(osiv)
and there would be reqirement to delete that data
which is used by these view
then will it not cumbersome to update all these views
according to our current data

suppose we delete that references from our tables
that is used by the views

so test all these view according to our updated data
and have to prepare to catch all the exception
that is generated by these types of views

and one more question
how i integrate hibernate in my web application

1) by using servlet filter
2) by using plugin in my struts-config file
3) Simply call the HibernateUtil class in my action class
and get the session and then doing all the operation

Suggest me which one will be better to use

Well, a transaction isolation level eliminates any problem here, so it's not to worry. And updating is not cumbersome - that is the whole purpose of Hibernate!!! :)



It is all done transactionally and each transaction is isolated. This is how every J2EE works, so it's no different for Hibernate or Toplink or Open Session in View or Session per query.



Each way you mention will work! The best and easiest way to implement "Open Session in View" is with a filter. That's always been my preference.

Great questions!

Thanks for your
reply
i want to discuss with you
of the making of HibernateUtil class
i declare in the HibernateUtil class


that is right
from that code we generate a particular session for each thread
that sounds good by using ThreadLocal class


but i saw
another declaration



that code is generate one transaction for particular thread
that sounds, little bit confuse me
suppose if thread first goes to save the data
but first it delete the data
then it save

then for all sql operation the one transaction is used

is it right
suppose transaction executes a long batch of query

why not consider a separate transaction

for each operation in the database
like save() or delete() or find by id()
means

for save operation
Transaction tx=session.beginTransaction()
getting the session
doing the database operation
then commit the transaction

same for delete

in the first case
for
one request
one session
one transaction

in second case
for
one request
one session
multiple transaction

can transaction should be unique for one request

ya i have one more question
do i need for setting the transaction
isolation
or
can i use default hibernate transaction isolation