I have upgraded application to use javax.faces-2.2.4 and primefaces-4.0 jars.After deploying my application to weblogic from myeclipse I am getting below error:
java.lang.IllegalStateException: Could not find backup for factory javax.faces.application.ApplicationFactory.
One of more common causes of this exception is that the webapp's runtime classpath is polluted with multiple different JSF API versions which are colliding/confusing each other.
This is likely also the case in your case. Weblogic itself already ships with JSF bundled, however you're supplying another one along with your webapp. So effectively you end up with two different versioned JSF APIs in the webapp's runtime classpath.
I don't do Weblogic, but basically you have 2 options:
Consult its admin documentation for clues.