Question

我的 SpringMVC 控制器中有下一个工作代码：

@RequestMapping(value = "/register", method = RequestMethod.GET)
public void registerForm(Model model) {
    model.addAttribute("registerInfo", new UserRegistrationForm());
}

@RequestMapping(value = "/reg", method = RequestMethod.POST)
public String create(
        @Valid @ModelAttribute("registerInfo") UserRegistrationForm userRegistrationForm,
        BindingResult result) {

    if (result.hasErrors()) {
        return "register";
    }
    userService.addUser(userRegistrationForm);
    return "redirect:/";
}

简而言之create方法尝试验证UserRegistrationForm。如果表单有错误，它会将用户留在同一页面上，其中填写的表单字段将显示错误消息。

现在我需要将相同的行为应用到另一个页面，但是我遇到了一个问题：

@RequestMapping(value = "/buy/{buyId}", method = RequestMethod.GET)
public String buyGet(HttpServletRequest request, Model model, @PathVariable long buyId) {
    model.addAttribute("buyForm", new BuyForm());
    return "/buy";
}

@RequestMapping(value = "/buy/{buyId}", method = RequestMethod.POST)
public String buyPost(@PathVariable long buyId,
                          @Valid @ModelAttribute("buyForm") BuyForm buyForm,
                          BindingResult result) {

    if (result.hasErrors()) {
        return "/buy/" + buyId;
    }

    buyForm.setId(buyId);
    buyService.buy(buyForm);
    return "redirect:/show/" + buyId;
}

我遇到了动态网址的问题。现在，如果表单有错误，我应该指定相同的页面模板以保留在当前页面上，但我也应该将buyId作为路径变量传递。这两个要求在哪里发生冲突。如果我按原样保留此代码，则会出现错误（我使用 Thymeleaf 作为模板处理器）：

Error resolving template "/buy/3", template might not exist or might not be accessible by any of the configured Template Resolvers

我可以编写类似return "redirect:/buy/" + buyId的内容，但在这种情况下，我会丢失表单对象的所有数据和错误。

我应该如何在buyPost方法中实现与create方法相同的行为？

Answer 1

本周末我尝试了这个post中提到的解决方案，但它对BindingResult不起作用。

以下代码有效但不完美。

@ModelAttribute("command")
public PlaceOrderCommand command() {
    return new PlaceOrderCommand();
}

@RequestMapping(value = "/placeOrder", method = RequestMethod.GET)
public String placeOrder(
        @ModelAttribute("command") PlaceOrderCommand command,
        ModelMap modelMap) {
    modelMap.put(BindingResult.MODEL_KEY_PREFIX + "command",
            modelMap.get("errors"));
    return "placeOrder";
}

@RequestMapping(value = "/placeOrder", method = RequestMethod.POST)
public String placeOrder(
        @Valid @ModelAttribute("command") PlaceOrderCommand command,
        final BindingResult bindingResult, Model model,
        final RedirectAttributes redirectAttributes) {
    if (bindingResult.hasErrors()) {
        redirectAttributes.addFlashAttribute("errors", bindingResult);

        //it doesn't work when passing this          
        //redirectAttributes.addFlashAttribute(BindingResult.MODEL_KEY_PREFIX + "command", bindingResult);

        redirectAttributes.addFlashAttribute("command", command);
        return "redirect:/booking/placeOrder";
    }
    ......
}

Answer 2

*我使用Hibernate Validator APIs来验证我的bean。要保留表单数据以及显示错误消息，您需要执行以下三项操作：

注释你的bean（例如@NotEmpty，@ Pattern，@ Length，@ Email等）

enter image description here

内部控制器：

@Controller 公共类RegistrationController {

@Autowired
private RegistrationService registrationService;

@RequestMapping(value="register.htm", method=RequestMethod.GET, params="new")
public String showRegistrationForm(Model model) {
    if (!model.containsAttribute("employee")) {
        model.addAttribute("employee", new Employee());
    }
    return "form/registration";
}

@RequestMapping(value="register.htm", method=RequestMethod.POST)
public String register(@Valid @ModelAttribute("employee") Employee employee, BindingResult bindingResult, RedirectAttributes redirectAttributes) {
    if (bindingResult.hasErrors()) {
        redirectAttributes.addFlashAttribute("org.springframework.validation.BindingResult.employee", bindingResult);
        redirectAttributes.addFlashAttribute("employee", employee);
        return "redirect:register.htm?new";
    }
    registrationService.save(employee);
    return "workspace";
}
// ....

}

更新您的view / jsp以保留错误消息：

enter image description here

这article肯定会有所帮助。

Answer 3

您可以将POST实施更改为：

@RequestMapping(value = "/buy/{buyId}", method = RequestMethod.POST)
public String buyPost(@PathVariable long buyId,
                          @Valid @ModelAttribute("buyForm") BuyForm buyForm,
                          BindingResult result) {

    buyForm.setId(buyId); // important to do this also in the error case, otherwise, 
                          // if the validation fails multiple times it will not work.

    if (result.hasErrors()) {
        byForm.setId(buyId);
        return "/buy/{buyId}";
    }

    buyService.buy(buyForm);
    return "redirect:/show/{buyId}";
}

如果您使用的是Spring 4.3或更高版本，也可以使用@PostMapping("/buy/{buyId}")注释该方法。

SpringMVC控制器：如果发生表单验证错误，如何保持在页面上

3 个答案: