[jboss-dev-forums] [JBoss AS 7 Development] - AS7, EJB3, JSF, JPA2: LazyInitializationException

[jabu10245]

jabu10245 [https://community.jboss.org/people/jabu10245] created the discussion

"AS7, EJB3, JSF, JPA2: LazyInitializationException"

To view the discussion, visit: https://community.jboss.org/message/648068#648068

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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 ;-)
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