title: Spring Web Flow flowExecutionUrl is empty
body: <p>I'm making simple order-flow via Spring Web Flow, also i have Spring MVC on my project. I've been doing everything according to guides, but my web-app doesn't react to my flow at all. Spring Web Flow Config: </p>
  
  <pre><code>     @Configuration
       @ComponentScan(basePackages = "config")
       public class WebFlowConfig extends AbstractFlowConfiguration {
  @Bean
  public FlowBuilderServices flowBuilderServices() {
      return getFlowBuilderServicesBuilder()
              .setViewFactoryCreator(mvcViewFactoryCreator())
              .setDevelopmentMode(true).build();
  }
  
  @Bean
  public MvcViewFactoryCreator mvcViewFactoryCreator() {
      MvcViewFactoryCreator factoryCreator = new MvcViewFactoryCreator();
      factoryCreator.setViewResolvers(
  
      Collections.singletonList(this.webMvcConfig.resourceViewResolver()));
      factoryCreator.setUseSpringBeanBinding(true);
      return factoryCreator;
  }
  @Autowired
  private DispatcherConfig webMvcConfig;
  
  @Bean
  public FlowDefinitionRegistry flowRegistry() {
     FlowDefinitionRegistry registry = getFlowDefinitionRegistryBuilder().addFlowLocation("/WEB-INF/flows/order/flowcnf.xml","order").build();
     return registry;
  }
  
  @Bean
  public FlowExecutor flowExecutor() {
      return
  
              getFlowExecutorBuilder(flowRegistry()).build();
  }
  
  @Bean
  public FlowHandlerMapping flowHandlerMapping(){
      final FlowHandlerMapping handeler = new FlowHandlerMapping();
      handeler.setFlowRegistry(flowRegistry());
      handeler.setFlowUrlHandler(defaultFlowUrlHandler());
      return handeler;
  }
  @Bean
  public DefaultFlowUrlHandler defaultFlowUrlHandler(){
      return new DefaultFlowUrlHandler();
  }
  
  @Bean
  public FlowHandlerAdapter adapter(){
      FlowHandlerAdapter adapter = new FlowHandlerAdapter();
      adapter.setFlowUrlHandler(defaultFlowUrlHandler());
      adapter.setFlowExecutor(flowExecutor());
      return adapter;
  }
  }
  </code></pre>
  
  <p>As I said I'm using Spring MVC maybe the problems occurs due to it.</p>
  
  <p>Code snippet below must run "thankCustomer" view-state, but it doesn't.
  I get 404 eror if i click the link.</p>
  
  <pre><code>&lt;a class=button href="${flowExecutionUrl}&amp;_eventId=thankCustomer"&gt;Замовити!&lt;/a&gt;
  </code></pre>
  
  <p>And the flow code: </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
    &lt;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="identify"&gt;
  &lt;var name="order" class="entity.BookOrder"/&gt; 
  
  &lt;subflow-state id="identify" subflow="order/custom" &gt;
      &lt;output name="user" value="order.custName" /&gt;
      &lt;transition on="userIsReady" to="buildOrder"/&gt;
  &lt;/subflow-state&gt;
  
  &lt;subflow-state id="buildOrder" subflow="order/build"&gt;
      &lt;input name="order" value="order" /&gt;
      &lt;transition to="takePayment" on="orderBuilt" /&gt;
  &lt;/subflow-state&gt;
  
  
  &lt;subflow-state id="takePayment" subflow="order/takePayment" &gt;
      &lt;input name="order" value="order"/&gt;
      &lt;transition on="paymentTaken" to="saveOrder" /&gt;
  &lt;/subflow-state&gt;
  &lt;action-state id="saveOrder"&gt;
      &lt;evaluate expression="userServiceImpl.addOrder(order.custName,order)"/&gt;
      &lt;transition to="thankCustomer" /&gt;
  &lt;/action-state&gt;
  
  &lt;view-state id="thankCustomer" view="/WEB-INF/pages/greeting.jsp" &gt;
      &lt;transition to="end-point" /&gt;
  &lt;/view-state&gt;
  
  &lt;end-state id="end-point"/&gt;
  
  &lt;global-transitions&gt;
      &lt;transition on="cancel" to="end-point" /&gt;
  &lt;/global-transitions&gt;
  
  &lt;/flow&gt;
  </code></pre>
  
  <p>I've tried to put flow id (order) instead of empty flowExecutionUrl, but still the same eror, I'll be grateful for any kinda help. </p>