Question

I am writing a wizard-like controller that handles the management of a single bean across multiple views. I use @SessionAttributes to store the bean, and SessionStatus.setComplete() to terminate the session in the final call. However, if the user abandons the wizard and goes to another part of the application, I need to force Spring to re-create the @ModelAttribute when they return. For example:

@Controller
@SessionAttributes("commandBean")
@RequestMapping(value = "/order")
public class OrderController
{
  @RequestMapping("/*", method=RequestMethod.GET)
  public String getCustomerForm(@ModelAttribute("commandBean") Order commandBean)
  {
    return "customerForm";
  }

  @RequestMapping("/*", method=RequestMethod.GET)
  public String saveCustomer(@ModelAttribute("commandBean") Order commandBean, BindingResult result)
  {
    [ Save the customer data ];
    return "redirect:payment";
  }

  @RequestMapping("/payment", method=RequestMethod.GET)
  public String getPaymentForm(@ModelAttribute("commandBean") Order commandBean)
  {
    return "paymentForm";
  }

  @RequestMapping("/payment", method=RequestMethod.GET)
  public String savePayment(@ModelAttribute("commandBean") Order commandBean, BindingResult result)
  {
    [ Save the payment data ];
    return "redirect:confirmation";
  }

  @RequestMapping("/confirmation", method=RequestMethod.GET)
  public String getConfirmationForm(@ModelAttribute("commandBean") Order commandBean)
  {
    return "confirmationForm";
  }

  @RequestMapping("/confirmation", method=RequestMethod.GET)
  public String saveOrder(@ModelAttribute("commandBean") Order commandBean, BindingResult result, SessionStatus status)
  {
    [ Save the payment data ];
    status.setComplete();
    return "redirect:/order";
  }

  @ModelAttribute("commandBean")
  public Order getOrder()
  {
    return new Order();
  }
}

If a user makes a request to the application that would trigger the “getCustomerForm” method (i.e., http://mysite.com/order), and there’s already a “commandBean” session attribute, then “getOrder” is not called. I need to make sure that a new Order object is created in this circumstance. Do I just have to repopulate it manually in getCustomerForm?

Thoughts? Please let me know if I’m not making myself clear.

Answer 1

Yes, sounds like you may have to repopulate it manually in getCustomerForm – if an attribute is part of the @SessionAttributes and present in the session, then like you said @ModelAttribute method is not called on it.

An alternative may be to define a new controller with only getCustomerForm method along with the @ModelAttribute method but without the @SessionAttributes on the type so that you can guarantee that @ModelAttribute method is called, and then continue with the existing @RequestMapped methods in the existing controller.