AbstractWizardFormController using Annotated @Controllers

Question

In Spring Framework , AbstractWizardFormController seems deprecated. How to implement multiple pages form in the Spring MVC Framework. (I am not using webflow)

any example or pointer would help considering my limited knowledge in Spring.

Answer 1

A @Controller is a more flexible way to define a form / wizard. You are supposed to map methods to requests based on requested path / request parameters / request method. So instead of defining a list of views and processing the request based on some required "step" parameter, you can define the steps of your wizard as you wish (also the command object will be handled more transparently). Here's how you can get to emulate a classic AWFC functionality (this is only meant to be an example, there's a lot more you can do).

@Controller
@RequestMapping("/wizard.form")
@SessionAttributes("command")
public class WizardController {

    /**
     * The default handler (page=0)
     */
    @RequestMapping
    public String getInitialPage(final ModelMap modelMap) {
        // put your initial command
        modelMap.addAttribute("command", new YourCommandClass());
        // populate the model Map as needed
        return "initialView";
    }

    /**
     * First step handler (if you want to map each step individually to a method). You should probably either use this
     * approach or the one below (mapping all pages to the same method and getting the page number as parameter).
     */
    @RequestMapping(params = "_step=1")
    public String processFirstStep(final @ModelAttribute("command") YourCommandClass command,
                                   final Errors errors) {
        // do something with command, errors, request, response,
        // model map or whatever you include among the method
        // parameters. See the documentation for @RequestMapping
        // to get the full picture.
        return "firstStepView";
    }

    /**
     * Maybe you want to be provided with the _page parameter (in order to map the same method for all), as you have in
     * AbstractWizardFormController.
     */
    @RequestMapping(method = RequestMethod.POST)
    public String processPage(@RequestParam("_page") final int currentPage,
                              final @ModelAttribute("command") YourCommandClass command,
                              final HttpServletResponse response) {
        // do something based on page number
        return pageViews[currentPage];
    }

    /**
     * The successful finish step ('_finish' request param must be present)
     */
    @RequestMapping(params = "_finish")
    public String processFinish(final @ModelAttribute("command") YourCommandClass command,
                                final Errors errors,
                                final ModelMap modelMap,
                                final SessionStatus status) {
        // some stuff
        status.setComplete();
        return "successView";
    }

    @RequestMapping(params = "_cancel")
    public String processCancel(final HttpServletRequest request,
                                final HttpServletResponse response,
                                final SessionStatus status) {
        status.setComplete();
        return "canceledView";
    }

}

I tried to vary the method signatures so that you can get an idea about the flexibility I mentioned. Of course, there's a lot more to it: you can make use of request method (GET or POST) in the @RequestMapping, you can define a method annotated with @InitBinder, etc.

EDIT: I had an unmapped method which I fixed (by the way, you need to make sure you don't have ambiguous mappings -- requests that could be mapped to more than one method -- or unmapped requests -- requests that cannot be mapped to any method). Also have a look at @SessionAttributes, @SessionStatus and @ModelAttribute, which are also needed for fully simulating the behaviour of the classic AWFC (I edited the code already to make this clear).