LazyInitializationException on @ManyToMany, although FetchType=EAGER

Question

Since I´m still facing the problem, after combing through all the solutions to this popular exception, here is my situation. In my case (a car pool), I have these two models :

@Entity
public abstract class Car {
    @GeneratedValue @Id
    private Long id;
    private String name;
    @ManyToMany (cascade = {CascadeType.ALL},  fetch = FetchType.EAGER) 
    @JoinTable  (name = "Car_Person", joinColumns=@JoinColumn(name = "CarId", referencedColumnName = "id"), 
             inverseJoinColumns=@JoinColumn(name = "personId", referencedColumnName = "id"))
    private List<Person> carUsers; 
    //rest omitted
}

And:

@Entity
public class Person {
    @GeneratedValue @Id
    private Long id;
    private String name;
    private int age;
        @ManyToMany(mappedBy = "carUsers", fetch = FetchType.EAGER)
        private List<Car> cars = new ArrayList<Car>();        
        //rest omitted
}

I even get a LazyInitializationException with FetchType=Fetch.EAGER, when I reference a Car in my JSF page like this:

<p:selectManyMenu value="#{carController.currentCar.carUsers}" converter="personConverter">     
    <f:selectItems value="#{personBean.persons}" var="person" itemLabel="#{person.name}" itemValue="#{person}"/>        
</p:selectManyMenu>

Where currentCar is a sub class of Car.

I think, there is no need for a query here, since JPA is resolving the m:n relation on it´s own, right?

Anyway, I get this stacktrace:

11:02:27,769 SEVERE [javax.enterprise.resource.webcontainer.jsf.context] (default task-42) org.hibernate.LazyInitializationException: failed to lazily initialize a collection, could not initialize proxy - no Session
    at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:587)
    at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:204)
    at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:148)
    at org.hibernate.collection.internal.PersistentBag.isEmpty(PersistentBag.java:266)
    at javax.faces.component.UIInput.isEmpty(UIInput.java:1272)
    at javax.faces.component.UIInput.validateValue(UIInput.java:1159)
    at javax.faces.component.UISelectMany.validateValue(UISelectMany.java:579)
    at javax.faces.component.UIInput.validate(UIInput.java:982)
    at javax.faces.component.UIInput.executeValidate(UIInput.java:1248)
    at javax.faces.component.UIInput.processValidators(UIInput.java:712)
    at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
    at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
    at org.primefaces.component.dialog.Dialog.processValidators(Dialog.java:423)
    at javax.faces.component.UIForm.processValidators(UIForm.java:253)
    at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
    at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1261)
    at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1195)
    at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
    at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
    at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
    at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
    at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
    at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
    at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
    at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
    at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
    at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
    at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
    at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)
    at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
    at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
    at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
    at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
    at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
    at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
    at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:805)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Any help would be highly appreciated.

try first changing `motUsers` to `carUsers` I see a wrong mappedby pointing in the Person class. — Jorge L. Morla, Jan 22 '18 at 12:34
sorry, I adjusted the class names to make the code more concise — Prefect73, Jan 22 '18 at 13:25
Take care of using EAGER on ToMany relationships. Read why: https://stackoverflow.com/questions/24150199/hibernate-many-to-many-fetch-method-eager-vs-lazy Probably it would be better to keep Lazy and initialize the collection with Hibernate.initialize or by using a EntityGraph — Simon Martinelli, Jan 22 '18 at 14:37
Thanks Simon, I know that EAGER is not quite recommendable. Could you tell me how and where to place `Hibernate.initialize`? — Prefect73, Jan 22 '18 at 15:05

Prefect73 · Accepted Answer · 2018-01-30T12:14:49.127

1

Ok, I found the answer here. Thanks to the great BalusC.

The problem is not only related to the Many-to-many relation, that´s why EAGER fetching didn´t help and not even the anti-patterns (hibernate.enable_lazy_load_no_trans, Open Session in View)

The real cause for the problem was the SelectManyMenu. You have to tell it, what kind of result set it should deal with. In my case I had to add the collectionType like this:

<p:selectManyMenu value="#carController.currentCar.motUsers}" collectionType="java.util.LinkedHashSet">

edited Jan 30 '18 at 12:14

answered Jan 26 '18 at 09:34

Prefect73

321
3
14

Thanks for adding the url to the 'answer elsewhere' – Kukeltje Jan 26 '18 at 09:54
[link](https://stackoverflow.com/questions/30103161/lazyinitializationexception-in-selectmanycheckbox-on-manytomanyfetch-lazy/30103575) You´re welcome – Prefect73 Jan 29 '18 at 11:27
You can edit your answer and add such a relevant thing there – Kukeltje Jan 29 '18 at 11:31

score 0 · Answer 2 · answered Jan 22 '18 at 21:40

Depending to you configuration , you should try this in your web.xml as a Filter to load lazily properties.

Hibernate (note on your spring and hibernate version to use correct version of org.springframework.orm.hibernate{***YOUR_VERSION***}):

<filter>
      <filter-name>hibernateFilter</filter-name>
      <filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
      <init-param>
         <param-name>sessionFactoryBeanName</param-name>
         <param-value>sessionFactory</param-value>
      </init-param>     
   </filter>
   <filter-mapping>
     <filter-name>hibernateFilter</filter-name>
    <url-pattern>/*</url-pattern>

Jpa:

<filter>
    <filter-name>oemInViewFilter</filter-name>
    <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
    <init-param>
        <param-name>entityManagerFactoryBeanName</param-name>
        <param-value>entityManagerFactory</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>oemInViewFilter</filter-name>
    <url-pattern>/*</url-pattern>

Thanks Moodi, but I get an `ClassNotFoundException: org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter` I´m on Wildfly and do not use spring. — Prefect73, Jan 23 '18 at 11:04
Yes, I´m using Maven. What exactly do you mean, if I´m using JPA? Wildfly automatically uses Hibernate as JPA provider. — Prefect73, Jan 23 '18 at 11:49

LazyInitializationException on @ManyToMany, although FetchType=EAGER

2 Answers2