Simple flow definition causes null pointer exception

[canard_gris]

Hi,

as a spring web flow newbie, I wrote the following simple flow definition:


<?xml version="1.0" encoding="UTF-8"?>
<flow xmlns="http://www.springframework.org/schema/webflow"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/webflow
http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd">

<start-state idref="firstState"></start-state>

<view-state id="firstState" view="firstView">
<transition on="ready" to="endState"/>
</view-state>

<end-state id="endState"/>

</flow>


which causes a null pointer exception:


java.lang.NullPointerException
at org.springframework.webflow.engine.builder.xml.Xml FlowBuilder.parseViewInfo(XmlFlowBuilder.java:625)
at org.springframework.webflow.engine.builder.xml.Xml FlowBuilder.parseAndAddViewState(XmlFlowBuilder.ja va:555)
at org.springframework.webflow.engine.builder.xml.Xml FlowBuilder.parseAndAddStateDefinitions(XmlFlowBui lder.java:525)
at org.springframework.webflow.engine.builder.xml.Xml FlowBuilder.buildStates(XmlFlowBuilder.java:341)
at org.springframework.webflow.engine.builder.FlowAss embler.directAssembly(FlowAssembler.java:105)
at org.springframework.webflow.engine.builder.FlowAss embler.assembleFlow(FlowAssembler.java:90)
at org.springframework.webflow.engine.builder.Refresh ableFlowDefinitionHolder.assembleFlow(RefreshableF lowDefinitionHolder.java:127)
at org.springframework.webflow.engine.builder.Refresh ableFlowDefinitionHolder.getFlowDefinition(Refresh ableFlowDefinitionHolder.java:88)
at org.springframework.webflow.definition.registry.Fl owDefinitionRegistryImpl.getFlowDefinition(FlowDef initionRegistryImpl.java:61)
at org.springframework.webflow.executor.FlowExecutorI mpl.launchExecution(FlowExecutorImpl.java:114)
at org.springframework.webflow.executor.FlowExecutorI mpl.executeFlowRequest(FlowExecutorImpl.java:108)
at org.springframework.webflow.context.servlet.Servle tExternalContext.executeFlowRequest(ServletExterna lContext.java:279)
at org.springframework.webflow.mvc.FlowController.han dleRequestInternal(FlowController.java:36)
at org.springframework.web.servlet.mvc.AbstractContro ller.handleRequest(AbstractController.java:153)
at org.springframework.web.servlet.mvc.SimpleControll erHandlerAdapter.handle(SimpleControllerHandlerAda pter.java:48)
at org.springframework.web.servlet.DispatcherServlet. doDispatch(DispatcherServlet.java:875)
at org.springframework.web.servlet.DispatcherServlet. doService(DispatcherServlet.java:809)
at org.springframework.web.servlet.FrameworkServlet.p rocessRequest(FrameworkServlet.java:476)
at org.springframework.web.servlet.FrameworkServlet.d oGet(FrameworkServlet.java:431)
...


Even an empty view-state like


<view-state id="firstState">
</view-state>


shows the same behaviour.

What's going wrong?

Thanx,
canard_gris

[Keith Donald]

I would recommend upgrading to 2.0 M4 and see if this fixes your problem.

[canard_gris]

Sorry, I'm just using 2.0 M4, and this doesn't fix my problem.

Further ideas?

[Keith Donald]

Hmmm... the stack trace above is not a M4 stack trace - it is definitely either M2 or M3. Can you post the stack trace you are seeing in M4?

Thanks

Keith