org.hibernate.LazyInitializationException at com.sun.faces.renderkit.html_basic.MenuRenderer.convertSelectManyValuesForModel

by

While submitting, the JSF UISelectMany components need to create a brand new instance of the collection with the submitted and converted values prefilled. It won’t clear out and reuse the existing collection in the model as that may either get reflected in other references to the same collection, or may fail with an UnsupportedOperationException because the collection is unmodifiable, such as the ones obtained by Arrays#asList() or Collections#unmodifiableList().

The MenuRenderer, the renderer behind UISelectMany (and UISelectOne) components who’s responsible for this all, will by default create a brand new instance of the collection based on collection’s getClass().newInstance(). This would in turn fail with LazyInitializationException if the getClass() returns an implementation of Hibernate’s PersistentCollection which is internally used by Hibernate to fill the collection property of an entity. The add() method namely needs to initialize the underlying proxy via the current session, but there’s none because the job isn’t performed within a transactional service method.

To override this default behavior of MenuRenderer, you need to explicitly specify the FQN of the desired collection type via the collectionType attribute of the UISelectMany component. For a List property, you’d like to specify java.util.ArrayList and for a Set property, you’d like to specify java.util.LinkedHashSet (or java.util.HashSet if ordering isn’t important):

<p:selectManyMenu ... collectionType="java.util.LinkedHashSet">

The same applies to all other UISelectMany components as well which are directly tied to a Hibernate-managed JPA entity. E.g:

<p:selectManyCheckbox ... collectionType="java.util.LinkedHashSet">
<h:selectManyCheckbox ... collectionType="java.util.LinkedHashSet">
<h:selectManyListbox ... collectionType="java.util.LinkedHashSet">
<h:selectManyMenu ... collectionType="java.util.LinkedHashSet">

See also the VDL documentation of among others <h:selectManyMenu>. This is unfortunately not specified in VDL documentation of <p:selectManyMenu>, but as they use the same renderer for converting, it must work. If the IDE is jerking about an unknown collectionType attribute and annoyingly underlines it even though it works when you ignore’n’run it, then use <f:attribute> instead.

<p:selectManyMenu ... >
    <f:attribute name="collectionType" value="java.util.LinkedHashSet" />
    ...
</p:selectManyMenu>

More Related Contents:

  1. JSF Controller, Service and DAO
  2. Showing Hibernate/JPA results in JSF datatable causes: java.lang.NumberFormatException: For input string: “[propertyname]”
  3. How do UISelectOne and UISelectMany components preselect defaults in f:selectItems
  4. LazyInitializationException in selectManyCheckbox on @ManyToMany(fetch=LAZY)
  5. javax.faces.application.ViewExpiredException: View could not be restored
  6. How and when should I load the model from database for h:dataTable
  7. Get JSF managed bean by name in any Servlet related class
  8. Conditionally displaying JSF components
  9. How to save uploaded file in JSF
  10. Invoke JSF managed bean action on page load
  11. Packaging Facelets files (templates, includes, composites) in a JAR
  12. Default action to execute when pressing enter in a form
  13. What URL to use to link / navigate to other JSF pages
  14. How to compare a char property in EL
  15. internationalization in JSF with ResourceBundle entries which are loaded from database
  16. PrimeFaces CSS skin not showing in login page, also JavaScript undefined errors
  17. How to write a file to resource/images folder of the app?
  18. Creating master-detail table and dialog, how to reuse same dialog for create and edit
  19. h:outputText seems to trim whitespace, how do I preserve whitespace?
  20. What is the function of @this exactly?
  21. How to insert special characters like & and < into JSF components' value attribute?
  22. How to conditionally render an f:selectItem tag?
  23. Customize primefaces chart
  24. How to display my application’s errors in JSF?
  25. How to use EL in PrimeFaces oncomplete attribute which is updated during action method
  26. Set a default time zone for f:convertDateTime
  27. Passing parameters to a view scoped bean in JSF
  28. Conditionally render a component based on selectOneMenu value
  29. JSF redirect to other page
  30. Skip required validation and invoke the application

Leave a Comment