Adding causes java.lang.IllegalStateException: Cannot create a session after the response has been committed

by

This is a known problem and has been reported by yours truly as issue 2215. This will occur when the response buffer has overflowed (due to large content) and the response is been committed before the session is been created. This is result of bit overzealous attempts of Mojarra to postpone “unnecessary” session creation as much as possible (which is at its own a Good Thing though).

Until they get it fixed, there are several workarounds:

  1. Create a Filter which does HttpServletRequest#getSession() before FilterChain#doFilter(). Advantage: no need to change JSF configuration/code. Disadvantage: when you want to avoid unnecessary session creation yourself as well.

  2. Call ExternalContext#getSession() with true in bean’s (post)constructor or preRenderView listener. Advantage: actually, nothing. Disadvantage: too hacky.

  3. Add a context parameter with name of com.sun.faces.writeStateAtFormEnd and value of false to web.xml. Advantage: unnecessary session creation will be really avoided as opposed to #1 and #2. Disadvantage: response will now be fully buffered in memory until </h:form> is reached. If your forms are not extremely large, the impact should however be minimal. It would however still fail if your <h:form> starts relatively late in the view. This may be combined with #4.

  4. Add a context parameter with name of javax.faces.FACELETS_BUFFER_SIZE and a value of the Facelets response buffer size in bytes (e.g. 65535 for 64KB) so that the entire HTML output or at least the <h:form> (see #3) fits in the response buffer. Advantage/disadvantage, see #3.

  5. Add a context parameter with name of javax.faces.STATE_SAVING_METHOD and value of client to web.xml. Advantage: session will not be created at all unless you have session scoped beans. It also immediately solves potential ViewExpiredException cases. Disadvantage: increased network bandwidth usage. If you’re using partial state saving, then the impact should however be minimal.

As to why the problem disappears when you remove <h:form>, this is because no session needs to be created in order to store the view state.

Update: this has as per the duplicate issue 2277 been fixed since Mojarra 2.1.8. So, you can also just upgrade to at least that version.

More Related Contents:

  1. How to use in JSF page? Single form? Multiple forms? Nested forms?
  2. Localization in JSF, how to remember selected locale per session instead of per request/view
  3. How to use EL with in id attribute of a JSF component
  4. java.lang.IllegalStateException:Could not find backup for factory javax.faces.application.ApplicationFactory
  5. Rendering other form by ajax causes its view state to be lost, how do I add this back?
  6. Clear JSF form input values after submitting
  7. Check if session exists JSF
  8. within not entirely working, only the last is processed
  9. Differences between action and actionListener
  10. Migrating from JSF 1.2 to JSF 2.0
  11. When to use valueChangeListener or f:ajax listener?
  12. What are the main disadvantages of Java Server Faces 2.0?
  13. CSS selector for a checked radio button’s label
  14. Using the HTML5 “required” attribute for a group of checkboxes?
  15. Error parsing XHTML: The content of elements must consist of well-formed character data or markup
  16. JSF convertDateTime renders the previous day
  17. Get current page programmatically
  18. How to update Mojarra version in GlassFish
  19. Changing JSF prefix to suffix mapping forces me to reapply the mapping on CSS background images
  20. Adding faces message to redirected page using ExternalContext.redirect()
  21. Uploading file using Google Apps Script using HtmlService
  22. Can you update an h:outputLabel from a p:ajax listener?
  23. java.lang.IllegalStateException: CDATA tags may not nest
  24. How to use p:graphicImage with StreamedContent within p:dataTable? [duplicate]
  25. Can you require two form fields to match with HTML?
  26. Primefaces valueChangeListener or
  27. Delphi Change main form while application is running
  28. h:commandButton not working inside h:dataTable
  29. JSF 2 dataTable row index without dataModel
  30. Ajax update and submission using h:commandButton

Leave a Comment