使用带注释的@Controllers的AbstractWizardFormController


问题内容

在Spring Framework中,AbstractWizardFormController似乎已弃用。如何在Spring MVC
Framework中实现多页表单。(我没有使用webflow)

任何示例或指针都将有助于考虑我在Spring方面的知识有限。


问题答案:

@Controller是定义表单/向导的更灵活的方法。您应该根据请求的路径/请求参数/请求方法将方法映射到请求。因此,您可以根据需要定义向导的步骤(而不是定义视图列表并根据某些必需的“
step”参数处理请求)(还将更透明地处理命令对象)。这是模拟经典AWFC功能的方法(这仅是一个示例,您可以做很多事情)。

@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";
    }

}

我试图改变方法签名,以便您对我提到的灵活性有所了解。当然,还有很多其他功能:您可以在中使用请求方法(GET或POST)@RequestMapping,可以定义带有注释的方法@InitBinder,等等。

编辑: 我有一个固定的未映射方法(顺便说一句,您需要确保您没有模棱两可的映射-可以映射到多个方法的请求-或未映射的请求-
无法被映射的请求映射到任何方法)。还可以查看@ SessionAttributes,@
SessionStatus和@ModelAttribute,它们也是完全模拟经典AWFC的行为所必需的(我已经编辑了代码以使这一点变得清楚)。