Spring MVC 既不是 BindingResult 也不是使用 ModelAndView 和 Form 标记的 bean 名称的普通目标对象答案

【问题标题】：Spring MVC Neither BindingResult nor plain target object for bean name using ModelAndView and Form tagSpring MVC 既不是 BindingResult 也不是使用 ModelAndView 和 Form 标记的 bean 名称的普通目标对象
【发布时间】：2016-12-17 09:28:50
【问题描述】：

即使我在这里阅读了一些问题和答案，我似乎也无法解决这个问题。我正在使用 spring mvc 并尝试制作会员信息编辑表单。

这是错误信息。

Neither BindingResult nor plain target object for bean name 'id' available as request attribute

我正在使用 Member.vo，它已经包含了所有需要的 getter 和 setter。

这是控制器。第一个是获取会员信息

@RequestMapping(value = "/setting", method = RequestMethod.GET)
    public String setting(HttpSession httpSession){

    String s_id = (String) httpSession.getAttribute("s_id");
    ModelAndView mav = new ModelAndView("memberedit");

     if(s_id !=null){
        Member member = membermapper.memberEdit(s_id);
        mav.addObject("command", member); }

return "setting"; }

这个正在上传会员的新信息

@RequestMapping(value = "/membereditadd", method = RequestMethod.POST)
     public String memberEdit(Model model, HttpSession httpSession){
        Member member = new Member();
        membermapper.editForm(member);

        String s_url = (String) httpSession.getAttribute("s_url");
        model.addAttribute("command", new Member());

        return "redirect:"+s_url;

    }

这是setting.jsp

<form action="membereditadd" commandName="command" method="post" name="form">

<label for="id">id</label>
 <form:input class="form-styling" type="text" path="id" />

 <label for="pw">password</label>
 <form:input class="form-styling" type="text" path="pw"/>

 <label for="email">e-mail</label>
 <form:input class="form-styling" type="text" path="email"/> 

        <input type="submit" class="btn-signin" value="submit">

     </form>

【问题讨论】：

标签： jsp spring-mvc model-view-controller javabeans

【解决方案1】：

这里有各种各样的问题。例如，您在 GET 处理程序中创建了一个 ModelAndView，然后返回一个纯字符串。您需要返回 ModelAndView。

我已经整理了一下。以下期望您的 JSP 被命名为 editMember.jsp

GET 处理程序：

/**
  * Spring MVC Controller. Loads an existing Member, sets it in the Model 
  * and forwards to the edit member page.
  *
  */
@RequestMapping(value = "/editMember", method = RequestMethod.GET)
public ModelAndView loadEditMemberForm(HttpSession httpSession){

    String s_id = (String) httpSession.getAttribute("s_id");
    ModelAndView mav = new ModelAndView("editMember");

     if(s_id != null){
        Member member = membermapper.memberEdit(s_id);
        mav.addObject("member", member); 
      }

    return mav; 
}

POST 处理程序：

/**
  * Spring MVC Controller. Handles form submit. Framework will automatically
  * bind for fields with path X to Member fields named X assuming corressponding
  * setter setX() is present.
  *
  */
@RequestMapping(value = "/editMember", method = RequestMethod.POST)
public String editMember(ModelAttribte("member") member, HttpSession httpSession, RedirectAttributes ra){
    Member member = new Member();
    membermapper.editForm(member);

    String s_url = (String) httpSession.getAttribute("s_url");

    //if you are using a redirect 
    //then you need to use RedirectAttributes
    //this makes the Member available to next view
    ra.addFlashAttribute("member", member);

    return "redirect:"+s_url;
}

更新表格。使用 'modelAttribute' 而不是 'command'。

<form:form modelAttribute="member" method="post">

    <label for="id">id</label>
    <form:input class="form-styling" type="text" path="id" />

    <label for="pw">password</label>
    <form:input class="form-styling" type="text" path="pw"/>

    <label for="email">e-mail</label>
    <form:input class="form-styling" type="text" path="email"/> 

    <input type="submit" class="btn-signin" value="submit">
</form:form>

【讨论】：