Question

I am using 3.1.1 here.

This works fine, the form is dislayed correctly

@RequestMapping(value={"/universities"}, params="new", method=RequestMethod.GET)
public String addUniversity(Model model) {
    model.addAttribute("addForm", AddForm.newUniversity());
    return "page/add-university";
}

When testing the validation error (by emptying the fields), this results in 500 internal server error, and displays stacktraces with the main message :
Neither BindingResult nor plain target object for bean name ‘addForm’ available as request attribute

This is the method :

@RequestMapping(value={"/universities"}, method=RequestMethod.POST)
public String submitNewUniversity(@Valid AddForm form, BindingResult binding) {
    if (binding.hasErrors()) {
        return "page/add-university";
    }

    // do others here ...
}

Here is my JSP :

<%@ taglib prefix="s" uri="http://www.springframework.org/tags" %>
<%@ taglib prefix="t" uri="http://tiles.apache.org/tags-tiles" %>
<%@ taglib uri="http://java.sun.com/jstl/core_rt" prefix="c" %>
<%@ taglib prefix="sf" uri="http://www.springframework.org/tags/form"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1" 
    session="false" %>

<s:url var="action" value="/universities" />
<sf:form method="POST" modelAttribute="addForm" action="${action}">         
   <fieldset> 
   <table cellspacing="0">
      <tr>
         <th><sf:label path="name">University:</sf:label></th>
         <td><sf:input path="name" size="30" /> <br/>
             <sf:errors path="name" cssClass="error" />
         </td>
      </tr>
      .....
</sf:form>

So far what i’ve researched are these :

• The bean name is correct, which is “addForm”, both in the controller and the JSP tile.
• The view exists, since displaying the form works fine.
• The field names in the JSP are also correct, since displaying the form works fine.
• The order of parameters are fine, BindingResult follows the command bean
• I am sure that the submitNewUniversity is called by the output of the logs i added

I wonder what i did wrong here ?

Answer 1

Found it !

I changed from

@Valid AddForm form

to

@Valid @ModelAttribute("addForm") AddForm form

Although this works fine, i tried removing the annotation and changing the form name to be the same variable name as the request attribute :

@Valid AddForm addForm

and this still throws the same error.

I guess i’ll just have to stick with @ModelAttribute from now on.