Warning : java.lang.IllegalArgumentException: .jsff is not a source file

Oracle JDeveloper 11.1.2.3

While running an application designed with TaskFlow & Page Fragments got below error

Warning: weblogic.utils.compiler.ToolFailureException: Unexpected exception while compiling jsps :java.lang.IllegalArgumentException: The file file:<Path>\page.jsff is not a source file
 
Solution - Add in web.xml file below lines to specifically recognize jsff page pattern.

<jsp-config>
    <jsp-property-group>
      <url-pattern>*.jsff</url-pattern>
      <is-xml>true</is-xml>
    </jsp-property-group>
</jsp-config>

 




Refer - https://blogs.oracle.com/jdevotnharvest/entry/warning_java_lang_illegalargumentexception_the