Neither BindingResult nor plain target obiect available as request attribute

当使用Spring MVC @Valid对输入框进行验证的时候，可能会遇到以下的异常：

Neither BindingResult nor plain target object for bean name ‘mybean’ available as request attribute

先看下controller:

@RequestMapping(value="/{userId}/updateUser",method=RequestMethod.POST)
    public String updateUser(@PathVariable int userId,@Valid SysUser user,BindingResult br)
    {
        if(br.hasErrors())
        {
            return "updateUser";
        }
        userServiceInter.update(user);
        return "redirect:/user/users";
    }

上面代码对user的输入进行验证，报以上错误，为了解决这个问题，我们需要在@Valid之后添加一个注解@ModelAttribute("user") SysUser user，然后在jsp页面的添加

<form modelAttribute="user"></form>，解决问题。

contriller:

@RequestMapping(value="/{userId}/updateUser",method=RequestMethod.POST)
    public String updateUser(@PathVariable int userId,@Valid @ModelAttribute("user")SysUser user,BindingResult br)
    {
        if(br.hasErrors())
        {
            return "updateUser";
        }
        userServiceInter.update(user);
        return "redirect:/user/users";
    }

update.jsp:

  <sf:form method="post" modelAttribute="user">
    <tr><td>userName:</td><td><sf:input path="userName"/><sf:errors path="userName"/></td></tr>
    <tr><td>userPwd:</td><td><sf:input path="userPwd"/><sf:errors path="userPwd"/></td></tr>
    <tr><td>email:</td><td><sf:input path="email"/><sf:errors path="email"/></td></tr>
    <tr><td>userStatus:</td><td><sf:input path="userStatus"/><sf:errors path="userStatus"/></td></tr>
    <tr><td>accountNonLocked:</td><td><sf:input path="accountNonLocked"/><sf:errors path="accountNonLocked"/></td></tr>
    <tr><td></td><td><input type="submit" value="update" onclick="javascript:return window.confirm('Are you sure to update')"/></td></tr>
  </sf:form>

另一补充一下：

org.springframework.validation.annotation是放在spring-context-4.0.0RELEASE.jar下。