Java 带ModelAndView的Spring MVC验证

我正在尝试将验证添加到我的SpringMVC应用程序中。在尝试设置验证之前，我一直在使用ModelAndView来提供jsp页面，但没有显示错误消息

模型

控制器

@RestController
@RequestMapping("/employee")
public class EmployeeController {

private static final Logger LOGGER = LogManager
        .getLogger(EmployeeController.class.getName());

@Autowired
private EmployeeServiceImpl employeeService;

@RequestMapping(value = "/new", method = RequestMethod.GET)
public ModelAndView getRegisterView(Model m) {
    return new ModelAndView("addEmployee", "employeeForm", new Employee());
}

@RequestMapping(value = "/register", method = RequestMethod.POST)
public ModelAndView postUser(@Valid Employee employee, BindingResult result) {
    ModelAndView model;
    if (result.hasErrors()) {
        model = new ModelAndView("addEmployee", "employeeForm", employee);
    } else {
        employeeService.addEmployee(employee);
        model = new ModelAndView();
        model.setViewName("displayEmployee");
        model.addObject("employees", employeeService.getEmployees());
    }

    return model;
}
}

形式

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清楚的

您自己在代码中破坏了模型，因此当返回页面时，基本上什么都没有了。当返回

ModelAndView

Spring时，MVC假设您已经准备并添加了自己渲染视图所需的所有内容

而是将

@modeldattribute（“employeeForm”）

添加到

@Valid

注释旁边的方法参数中，并使用

BindingResult

中已经存在的模型来构建

模型和视图

@RequestMapping(value = "/register", method = RequestMethod.POST)
public ModelAndView postUser(@Valid @ModelAttribute("employeeForm" Employee employee, BindingResult result) {
    ModelAndView model;
    if (result.hasErrors()) {
        model = new ModelAndView("addEmployee", result.getModel());

虽然这会起作用，但为什么不简单地返回一个
字符串作为视图的名称，并在需要时进行一些
模型的准备工作呢

@RequestMapping(value = "/register", method = RequestMethod.POST)
public String postUser(@Valid @ModelAttribute("employeeForm") Employee employee, BindingResult result, Model model) {
    if (result.hasErrors()) {
        return "addEmployee";
    } else {
        employeeService.addEmployee(employee);
        model.addObject("employees", employeeService.getEmployees());
        return "displayEmployee";
    }
}

我甚至认为，为
displayEmployee
页面填充
Model
不属于这里，而是用一种单独的方法为该页面准备模型
 看起来很完美，我知道我还没有应用到最佳实践中。我现在只是想推出一个粗略的工作版本。谢谢你的帮助！
model = new ModelAndView("addEmployee", "employeeForm", employee);

@RequestMapping(value = "/register", method = RequestMethod.POST)
public ModelAndView postUser(@Valid @ModelAttribute("employeeForm" Employee employee, BindingResult result) {
    ModelAndView model;
    if (result.hasErrors()) {
        model = new ModelAndView("addEmployee", result.getModel());

@RequestMapping(value = "/register", method = RequestMethod.POST)
public String postUser(@Valid @ModelAttribute("employeeForm") Employee employee, BindingResult result, Model model) {
    if (result.hasErrors()) {
        return "addEmployee";
    } else {
        employeeService.addEmployee(employee);
        model.addObject("employees", employeeService.getEmployees());
        return "displayEmployee";
    }
}