Spring Webflow - IllegalStateException when using multipart/form-data and file upload - file-upload

Question

I am trying to add file upload to my Spring Webflog form processing. As far as the form enctype is not set to multipart/form-data, form submition works just fine. But after I added enctype="multipart/form-data" to my Spring form, this Exception occurs:
java.lang.IllegalStateException: A flow execution action URL can only be obtained in a RenderRequest or a ResourceRequest
at org.springframework.webflow.context.portlet.PortletExternalContext.getFlowExecutionUrl(PortletExternalContext.java:215)
at org.springframework.webflow.engine.impl.RequestControlContextImpl.getFlowExecutionUrl(RequestControlContextImpl.java:178)
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:189)
at org.springframework.webflow.engine.ViewState.render(ViewState.java:293)
at org.springframework.webflow.engine.ViewState.refresh(ViewState.java:242)
at org.springframework.webflow.engine.ViewState.resume(ViewState.java:220)
at org.springframework.webflow.engine.Flow.resume(Flow.java:537)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:259)
at org.springframework.webflow.executor.FlowExecutorImpl.resumeExecution(FlowExecutorImpl.java:169)
at org.springframework.webflow.mvc.portlet.FlowHandlerAdapter.handleAction(FlowHandlerAdapter.java:161)
at org.springframework.web.portlet.DispatcherPortlet.doActionService(DispatcherPortlet.java:670)
at org.springframework.web.portlet.FrameworkPortlet.processRequest(FrameworkPortlet.java:520)
at org.springframework.web.portlet.FrameworkPortlet.processAction(FrameworkPortlet.java:461)
at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:71)
I have added CommonsMultipartResolver to my spring context:
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- Limit uploads to one byte smaller than the server is allowed to handle -->
<property name="maxUploadSize" value="100000" />
</bean>
and have commons-fileupload.jar in my pom.xml:
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency>
My JSP looks like this:
<portlet:actionURL var="processFormAction" >
<portlet:param name="execution" value="${flowExecutionKey}"/>
</portlet:actionURL>
<form:form action="${processFormAction}" modelAttribute="customerModel" enctype="multipart/form-data" method="post" >
<form:input path="firstName" cssClass="input-size-1 valid-required" />
<form:input path="lastName" cssClass="input-size-1 valid-required" />
<input name="avatar" id="avatar" type="file"/>
<input type="submit" name="_eventId_submit" id="send" value="Submit"/>
</form:form>
My flow.xml definition:
<view-state id="state1" model="customerModel">
...
<transition on="submit" to="submitFormActions"/>
</view-state>
<action-state id="submitFormActions">
<evaluate expression="portletAction.processForm(customerModel, flowRequestContext)" />
<transition on="success" to="state2"/>
<transition on="error" to="state1" />
</action-state>
The model object:
public class CustomerModel implements Serializable{
private String firstName;
private String lastName;
private MutlipartFile avatar;
...
//public getters and setters
}
Any thoughts what could be wrong? As I said, without enctype="multipart/form-data" the form processing works well.
Thanks

Answer 1

You are using org.springframework.web.multipart.commons.CommonsMultipartResolver which is not aware about the portlet context.
You need to change CommonsMultipartResolver to:
<bean id="portletMultipartResolver"
class="org.springframework.web.portlet.multipart.CommonsPortletMultipartResolver">
<!-- one of the properties available; the maximum file size in bytes -->
<property name="maxUploadSize" value="100000"/>
</bean>
Also, for this bean to be recognised by DispatcherPortlet, you need to define this bean id as mentioned above. The doc says:
Any configured PortletMultipartResolver bean must have the following id (or name): "portletMultipartResolver".
If you have defined your PortletMultipartResolver with any other name, then the DispatcherPortlet will not
find your PortletMultipartResolver, and consequently no multipart support will be in effect.