The foreach tag in JSP and how to write the code in the Java controller

Question

I have one controller (RegisteredController.java) , and I want that the output of the controller is displayed in the JSP (its name is commment_form.jsp). So I use a forEach tag in the jsp to display a list of comments (the comments which the user has inserted about a given resource). For "resource" I usually mean an image. So there are a list of comments about an "image" and I want that all the comments are all displayed in the bottom page, when a comment is going to be inserted into the comment form. My question is how must be written the code into the controller in order to set the output for the jsp ? Should I use a @ModelAttribute , a put-attribute or something else ? Here is the code of the controller and of the jsp :

The comment_form.jsp is:

<form:form modelAttribute="comments">
   <table class="commento">                
      <tr>
         <th/>
         <th>ID</th>
         <th>Contenuto</th>
      </tr>

      <c:forEach items = "${comments}" var="comment">
       <tr>
           <td><c:out value="${comments.content}"></c:out></td>
           <td><c:out value="${comments.content}</c:out></td>
       </c:forEach>
    </table>
  </form:form>

The RegisteredController.java is:

 @RequestMapping("/comment.do")
 public String comment(@ModelAttribute Comment comment, BindingResult             
 bindingResult,         Model model, Locale locale) {
    User user=userService.getUserCurrent();
    comment.setDatePubblication(SQLUtility.getCurrentDate());
    comment.setIdUser(user.getId());
    commentService.create(comment);
    Object[] args = { comment.getId() };
    String message = messageSource.getMessage("message.update", args,locale);

    List<Comment> comments = 
    commentService.findAllCommentByResource(comment.getIdResource());

    model.addAttribute("comments", comments);

    model.addAttribute("id",comment.getIdResource());

    model.addAttribute("message", message);

    model.addAttribute("comment", comment);

    return "redirect:/registered/comment_start.do";
}

Please any help ? I will appreciate . Thanks you.

PLEASE DON'T SHOUT *(I've fixed it for you on this occasion.)* Also, tags don't go in the title. I've removed the "spring mvc" tag from the title and added it to the tags. — T.J. Crowder, Jul 27 '14 at 12:47

score 0 · Answer 1 · edited Jun 20 '20 at 09:12

0

In case of redirect pass additional data as redirect attributes.

To carry data across a redirect use RedirectAttributes#addFlashAttribute(key, value).

What Java doc says:

A RedirectAttributes model is empty when the method is called and is never used unless the method returns a redirect view name or a RedirectView.

After the redirect, flash attributes are automatically added to the model of the controller that serves the target URL.

One extra note :

In JSP it should be ${comment.content} instead of ${comments.content}

edited Jun 20 '20 at 09:12

Community

1
1

answered Jul 27 '14 at 12:47

Braj

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In my case what should I write for key and value ? – user3834282 Jul 27 '14 at 13:02
It depends on what is needed at client side? Read more about [Expression Language](http://stackoverflow.com/tags/el/info) – Braj Jul 27 '14 at 13:04
I need the list of comments (it is a collections) declared List – user3834282 Jul 27 '14 at 14:41
I used the redirectAttributes but it returns an error, the following --> Required Long parameter 'id' is not present – user3834282 Jul 27 '14 at 14:43
I used the redirectAttributes but it returns an error, the following --> Required Long parameter 'id' is not present – – user3834282 Jul 27 '14 at 14:45
No idea what are you doing, take your time and read more about it. follow the link that I shared you and read in documentation. – Braj Jul 27 '14 at 14:50
I found the answer by reading the link http://stackoverflow.com/questions/16482355/foreachspring-doesnt-work-in-jsp – user3834282 Jul 27 '14 at 15:47

The foreach tag in JSP and how to write the code in the Java controller

1 Answers1