Spring Webflow - IllegalStateException when using multipart/form-data and 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.