Why is hibernate returning a proxy object?

Question

I have a service method that calls a DAO which then returns an object from the database. This method is called from numerous parts of the system. However, one particular method

Answer 1

In my opinion this expression:

hibernateTemplate.find("from User u where u.username = ?", username)

Should always return POJO, not a proxy. This is because standard HQL/criteria returns non-proxied object, but objects of your original entity classes. This is different from lazy associations fetching:

@Entity
class X {
    @ManyToOne(fetch = FetchType.LAZY)
    private User user;
}

Getting X object from the db here, we will have a lazy proxy in X.user field (a proxied User instance).

Now, it happens that doing from User where [...] you sometimes have POJO and sometimes proxy object. Usually this is because in some executions User object was first fetched from the db through associations (from X where [...] query was called first in given hibernate session). Having already (proxied) User instance, hibernate will reuse this instance even for your plain queries like from User where [...].