AS7, EJB3, JSF, JPA2: LazyInitializationException
jabu10245 Jan 22, 2012 10:16 AMHello 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 FooManagerto 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 ;-)