AS7, EJB3, JSF, JPA2: LazyInitializationException

[jabu10245]

Hello Forum,

I'm new to AS7 etc. and I'm trying to create a little EAR project in the Standalone environment.

Here's my project configuration (using Maven):

myapp.ear:

<ear>/META-INF/application.xml:

[...]
<module><ejb>myapp-ejb.jar</ejb></module>
<module><web><web-uri>myapp-jsf.war</web-uri></web></module>
<library-directory>lib</library-directory>

<ear>/lib/commons-lang.jar

<ear>/myapp-ejb.jar

<ear>/myapp-jsf.war

myapp-ejb.jar:

<jar>/META-INF/beans.xml => empty beans.xml

<jar>/META-INF/persistence.xml:

[...]
<persistence-unit name="primary">
    <jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>
    <properties>
        <property name="hibernate.hbm2ddl.auto" value="create-drop" />
    </properties>
</persistence-unit>

and an EJB (for testing purpose as singleton):

@LocalBean
@Named("fooManager")
@Singleton @Startup
public class FooManagerBean implements FooManager {
    private @PersistenceContext EntityManager entityManager;

    public Foo getFoo(String name) { /* JPA lookup using entityManager */ }
}

The class Foo is just a mapped entity having Foos as children:

@Entity @Table(name = "foo")
public class Foo implements Serializable {
    @Column(name = "name", nullable = false, unique = true, length = 64)
    private String name;

    @ManyToOne
    private Foo parent;  // nullable

    @OneToMany(mappedBy = "parent")
    private List<Foo> children;

    // Getters and Setters, hashCode, equals, toString
}

myapp-jsf.war:

<war>/WEB-INF/beans.xml => empty beans.xml

<war>/WEB-INF/faces-config.xml => empty JSF 2.0 config xml

<war>foo.xhtml => displays all root foos with all their children => LazyInitializationException

@Named @RequestScoped
public class FooController implements Serializable {
[...]
}

The FooController uses the

@EJB FooManager

to load all root Foo objects, the foo.xhtml should display them with

all their children. The root Foo objects are being loaded correctly, but when I try to access the

children a LazyInitializationException is being thrown, because I access them outside the transaction

scope of the Entity Manager from the FooManager.

My question is: Is there something like Spring's OpenEntityManagerInViewInterceptor?

I googled it and found some descriptions using Seam, but I have no experience with that. Is Seam

party of JBoss AS7? Or do I have to include it in my WAR as a dependency? What version should I

use? Or is there any simpler way solving my problem?

Thanks to anyone who can point me to a solution ;-)

[sfcoy]

Strictly speaking this is not a JBoss AS7 issue and you would probably be better off checking over on the Hibernate Forums.

I will mention that you should be loading your Foo objects with a query that performs a fetch join as described in 16.3. Associations and joins, otherwise your application will scale horribly with "N+1 SELECT" problems, even if you use something like the OpenEntityManagerInViewInterceptor.

[david_sing]

Try it with an extended persistence context.

{code}
@PersistenceContext(type=PersistenceContextType.EXTENDED)
private EntityManager em;
{code}