LazyInitializationException using HibernateDaoSupport

I'm trying to use HibernateDaoSupport but I'm getting stuck with a org.hibernate.LazyInitializationException problem.

This is an example of what I want to do;

public class MyDaoImpl extends HibernateDaoSupport {

    public Set<Long> getCoreItemIdsForCustomerIds(Set<Long> customerIds) {
        Set<Long> itemIds = new HashSet<Long>();
        for (Long customerId : customerIds) {
            Customer customer = getCustomerWithId(customerId);
            itemIds.addAll(getItemIdsFromItems(customer.getCoreItems()));
        }
        return itemIds;
    }

    private Customer getCustomerWithId(Long customerId) {
        return getHibernateTemplate().get(Customer.class, customerId);
    }

    private Set<Long> getItemIdsFromItems(Set<Item> items) {
        Set<Long> itemIds = new HashSet<Long>();
        for (Item item : items) {
            itemIds.add(item.getId());
        }
        return itemIds;
    }
}

A Customer has a collection 开发者_Python百科of Items. The entity is Fetched lazily, so I guess the problem is after getCustomerWithId completes the session is closed, and 'customer' is now detached. So when customer.getCoreItems() is invoked the exception is thrown.

Does any one know how I can use HibernateDaoSupport and keep the session open until getCoreItemIdsForCustomerIds returns?

Or do I need to start and close the transaction manually myself to do this?

Hope that has made sense! Thanks.

Use the OpenSessionInView filter. The session will be open for the duration of the request-response render phase.