And the correct answer is "user error". I'm building CAS via maven. I created profiles to hold logging, and then incorrectly configured it so that the default_views.properties file wasn't in the profiles. As a result, when CAS did its overlay as part of the maven build, it included the baseline default_views.properties instead of my copy.
NPE while trying to render a View in Spring Webflow
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26-06-2022 - |
Question
When trying to use a webflow, I keep getting the following error:
{
"failure":"true",
"exception.message":"org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing org.springframework.webflow.action.ViewFactoryActionAdapter@200a5beb in state 'accountCannotLogInView' of flow 'login' -- action execution attributes were 'map[[empty]]'",
"exception.stacktrace":"org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing org.springframework.webflow.action.ViewFactoryActionAdapter@200a5beb in state 'accountCannotLogInView' of flow 'login' -- action execution attributes were 'map[[empty]]'
...
Caused by: java.lang.IllegalStateException: Exception occurred rendering view null
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:191)
at org.springframework.webflow.action.ViewFactoryActionAdapter.doExecute(ViewFactoryActionAdapter.java:40)
at org.springframework.webflow.action.AbstractAction.execute(AbstractAction.java:188)
at org.springframework.webflow.execution.ActionExecutor.execute(ActionExecutor.java:51)
... 66 more
Caused by: java.lang.NullPointerException
at org.springframework.webflow.mvc.servlet.ServletMvcView.doRender(ServletMvcView.java:50)
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:187)
... 69 more
"
}
Does anybody have any idea what the cause of this might be? From my login-webflow.xml:
<action-state id="checkAccountType">
<evaluate expression="lookupAccountTypeAction.lookup(flowScope.principal)" />
<transition on="EMAIL" to="accountCannotLogInView" />
<transition on="Login" to="checkAccountStatus" />
<transition on="CONTACT" to="accountCannotLogInView" />
</action-state>
<end-state id="accountCannotLogInView" view="myAccountCannotLogInView"/>
From default_views.properties:
myAccountCannotLogInView.(class)=org.springframework.web.servlet.view.JstlView
myAccountCannotLogInView.url=/WEB-INF/view/jsp/default/ui/myAccountCannotLogInView.jsp
From my log file:
2013-09-09 08:29:25,645 DEBUG [org.springframework.webflow.engine.EndState] - Entering state 'accountCannotLogInView' of flow 'login'
2013-09-09 08:29:25,645 DEBUG [org.springframework.webflow.execution.ActionExecutor] - Executing org.springframework.webflow.action.ViewFactoryActionAdapter@359d136a
2013-09-09 08:29:25,645 DEBUG [org.springframework.webflow.mvc.view.AbstractMvcView] - Rendering MVC [null] with model map [{flowRequestContext=[RequestControlContextImpl@55bf756b externalContext = org.springframework.webflow.mvc.servlet.MvcExternalContext@2bb4d74, currentEvent = EMAIL, requestScope = map['ticketGrantingTicketId' -> 'TGT-1-GxALVR7PEtbagbnRlStOTbHoRHlb61YVm1m2hvWx3pgWCEXgPb-cas01.example.org'], attributes = map[[empty]], messageContext = [DefaultMessageContext@cb5efc8 sourceMessages = map[[null] -> list[[empty]]]], flowExecution = [FlowExecutionImpl@3f5c0d33 flow = 'login', flowSessions = list[[FlowSessionImpl@419d87bc flow = 'login', state = 'accountCannotLogInView', scope = map['principal' -> sso_test_user, 'userInfoBean' -> com.mycompany.authentication.UserInfoBean@54394557[username=<null>,firstName=<null>,lastName=<null>,emailAddress=<null>,streetAddress=<null>,city=<null>,state=<null>,zip=<null>,country=<null>], 'changePasswordBean' -> com.mycompany.authentication.ChangePasswordBean(username=null, newPassword=null, confirmNewPassword=null), 'service' -> https://my.server.com:443/casauth/facade/norenew?idp=https://my.server.com/idp/externalAuthnCallback, 'credentials' -> [username: sso_test_user], 'warnCookieValue' -> false, 'ticketGrantingTicketId' -> 'TGT-1-GxALVR7PEtbagbnRlStOTbHoRHlb61YVm1m2hvWx3pgWCEXgPb-cas01.example.org']]]]], flashScope=map[[empty]], principal=sso_test_user, currentUser=null, userInfoBean=com.mycompany.authentication.UserInfoBean@54394557[username=<null>,firstName=<null>,lastName=<null>,emailAddress=<null>,streetAddress=<null>,city=<null>,state=<null>,zip=<null>,country=<null>], changePasswordBean=com.mycompany.authentication.ChangePasswordBean(username=null, newPassword=null, confirmNewPassword=null), service=https://my.server.com:443/casauth/facade/norenew?idp=https://my.server.com/idp/externalAuthnCallback, credentials=[username: sso_test_user], flowExecutionKey=e1s1, warnCookieValue=false, flowExecutionUrl=/authentication/login?username=%5BLjava.lang.String%3B%405b65afa5&submit=%5BLjava.lang.String%3B%4070eea883&_eventId=%5BLjava.lang.String%3B%4044796a61&service=%5BLjava.lang.String%3B%407f372965<=%5BLjava.lang.String%3B%407e7ee722&password=%5BLjava.lang.String%3B%403d78aa0f&execution=%5BLjava.lang.String%3B%403ce4de50, ticketGrantingTicketId=TGT-1-GxALVR7PEtbagbnRlStOTbHoRHlb61YVm1m2hvWx3pgWCEXgPb-cas01.example.org}]
2013-09-09 08:29:25,645 DEBUG [org.springframework.webflow.engine.impl.FlowExecutionImpl] - Attempting to handle [org.springframework.webflow.execution.ActionExecutionException: Exception thrown executing org.springframework.webflow.action.ViewFactoryActionAdapter@359d136a in state 'accountCannotLogInView' of flow 'login' -- action execution attributes were 'map[[empty]]'] with root cause [java.lang.NullPointerException]
2013-09-09 08:29:25,645 DEBUG [org.springframework.webflow.engine.impl.FlowExecutionImpl] - Rethrowing unhandled flow execution exception
And yes, the file does exist in that location. I've been banging on this for a few days, so if anybody has any insight, I'd really appreciate it.
Solution
OTHER TIPS
it seems like your property is not parsed to your flow.xml.
defining your view hardcoded should work.
see here: Specifying view identifiers
The reason for this issue is: The JSP view is not found.
In cas-servlet.xml, mention the properties file which has the basename of the custom JSP view inside the "viewResolver" bean as below:
<bean id="viewResolver"
class="org.springframework.web.servlet.view.ResourceBundleViewResolver"
p:order="0">
<property name="basenames">
<util:list>
<value>${cas.viewResolver.basename}</value>
<value>custom_view</value>
<value>protocol_views</value>
</util:list>
</property>
</bean>
And in the custom_view.properties, mention the following:
casRegisterView.(class)=org.springframework.web.servlet.view.JstlView
casRegisterView.url=/WEB-INF/view/jsp/default/ui/casRegisterView.jsp
Here the JSP view is "casRegisterView.jsp". Place custom_view.properties in /src/main/resources.