Dealing Gracefully with ViewExpiredException in JSF2

My previous entry dove under the covers for JSF 2.0 and examined composite component metadata. This one is far less esoteric and shows how to handle the ViewExpiredException using a new JSF feature, the ExceptionHandler, contributed by Pete Muir a JSF Expert Group representative from JBoss. JSF throws a ViewExpiredException when a postback is made to a view and, for whatever reason, that view cannot be restored. Usually this is due to a session timeout, but a custom state management solution could also cause this exception to be thrown. The default behavior in JSF2 is to show the Facelets error page saying View Expired. The default page is illustrated at right. One way to fix this is to declare an element in your web.xml, as shown here.             javax.faces.application.ViewExpiredException         /faces/viewExpired.xhtml       This works well enough. You can even put JSF components on the error page if you put the proper Faces Servlet mapping in the element, as shown above. If you want to do some application level manipulation in response to the exception, you'll want something different, however. In this case, a custom ExceptionHandler is just the trick. I cover this in much more detial in my upcoming book, JavaServer Faces 2.0: The Complete Reference, and the example shown in this blog entry is neatly integrated into the chapter 10 sample...

Date: September, 03 2009
Url: http://www.java.net/blog/edburns/archive/2009/09/03/dealing-gracefully-viewexpiredexception-jsf2

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