Question

I have a Struts 1.3 and Hibernate 3.1 application that uses an open-session-in-view pattern for maintaining hibernate transactions. After I do a session.save() on an object its identifier is being set in the object, however after I pass the object to a new action class all of the properties that are managed by hibernate, like the object’s identifier are being set to null.

The client isn’t using Spring so I had to write my own request filter implementation of the pattern which looks like:

//get a transaction from JTA
transaction = (UserTransaction)new InitialContext().lookup("java:comp/UserTransaction");

        transaction.begin();

        // Call the next filter (continue request processing)
chain.doFilter(request, response);

// Commit and cleanup
log.finer("Committing the database transaction");
transaction.commit();

My SaveActionClass calls a service layer to persist the object and its associated list (where I’m controlling the session) looks like this:

this.saveAddresses(vendor); //saves a persistant set to the database via dao

this.saveExpCodes(vendor, expCodes); //saves a persistant set to the database  via dao

this.savePhoneNumbers(vendor); //saves a persistant set to the database  via dao

vendor.save(); //saves the vendor object to the database via dao

session.flush();  

session.refresh(vendor);

After the vendor object is persisted the vendor object and all of its children objects have valid identifiers. The vendor object is then added to a DynActionForm property and then forwarded to a ViewActionClass:

dynaActionForm.set(VENDOR_PROPERTY_NAME, vendor);

return actionMapping.findForward(target); //viewvendor

Then in the ViewActionClass when I get the vendor property all the identifiers are set to null:

Vendor vendor = (Vendor)dynaActionForm.get(VENDOR_PROPERTY_NAME); //vendorid is now null

Why is the persistent object losing its identifiers when its being passed from one action class to another via property in dynActionForm?

Answer 1

The trick here was the placement of the session.refresh() in the getVendor service method:

public Vendor getVendor(Vendor vendor, Boolean refresh) {
    Session session = HibernateUtil.getSession();

    session.setFlushMode(FlushMode.MANUAL);

        //refreshing the session here before the get call gave me the would still set some properties to null
        /*
        if(refresh.booleanValue()){
        session.refresh(vendor);
    }
    */

    vendor = vendor.get();

        //however putting the refresh here, after the get() call populated the vendor object properly
    if(refresh.booleanValue()){
        session.refresh(vendor);
    }
        ....
}