Failed to Laizy load the Collection

[efmcuiti]

Hello everyone,

I'm using jboss 4.0.5 GA and EJB3 specification with JPA(Java Persistence API). In one persistent entity a have something like this:

@OneToMany
private Collection roles;

But when in my web application (in a Servlet or jsp) i do something like this:

Collection roles = user.getRoles() (in a servlet)
or
${user.roles} (in a JSP),

The jboss console displays:

Laizy Initialization failed in collection of role: org.tha.Role (or something like this)

I don't know if have something related with entity managers or with the database that i'm using (Mysql 4.1).

Thanks if you people can help me.

[efmcuiti]

Here is the error message that the jboss console throws:

org.hibernate.lazyInitializationException: failed to lazily initialize a collection of role: org.tha.User.roles, no session or session was closed

I hope you can help me

[reubenf]

I think the problem is as follows: With lazy loading, objects are not loaded until referenced. Until then, references are to proxy objects. So, since all loads need to be done in the context of a session, if you load a parent object and never reference the child object until after the session has been closed, you will get a lazy initialization exception

[efmcuiti]

"reubenf" wrote:
I think the problem is as follows: With lazy loading, objects are not loaded until referenced. Until then, references are to proxy objects. So, since all loads need to be done in the context of a session, if you load a parent object and never reference the child object until after the session has been closed, you will get a lazy initialization exception

Yes, i've realized that before.... but there is no way to configure the container in order to work with lazy load without problems?

Thanks

[nschweig]

Hi,

I have got the same problem. In the hibernate forum they say that you have to use the opensessioninview pattern.
http://www.hibernate.org/43.html

If you use Spring (I do not) there ist a OpenSessionInViewFilter you can use (I think you only have to configure it in the web.xml)
But I do not really understand how to implement the OSIV-Pattern by myself when I use EJB.... ???
Perhaps you have some ideas.

Nicki