Question

I am using spring framework 3.
I have a form for posting comments to the article. When the form is submitted, it is checked if there any errors.
In case there is no errors, controller returns string

"redirect:entryView/"+comment.getEntryId();

And everything is okay.

But when there are some errors, if controller returns

"redirect:entryView/"+comment.getEntryId();

The errors should be displaed near the form with spring-form.tld tags:

<form:errors path="author"/>

But there are no displayed errors!
When i am trying to return

"entryView/"+comment.getEntryId();

Without redirect: prefix, then it is going to /rus/WEB-INF/jsp/entryView/8.jsp and there is HTTP Status 404. But it must go to http://example.com/rus/entryView/8, i.e page where the article and form for comments are!

This is view resolver:

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
</bean>

What should i do?

Rest of controller:

@Controller
public class CommentController {
private RusService rusService;
private CommentValidator commentValidator;
@Autowired
public CommentController(RusService rusService,CommentValidator commentValidator){
    this.rusService = rusService;
    this.commentValidator = commentValidator;
}
@RequestMapping(value="/addComment",method=RequestMethod.POST)
public String addComment(Comment comment,BindingResult result){
    commentValidator.validate(comment, result);
    if(result.hasErrors()){
        return "redirect:entryView/"+comment.getEntryId();
    }else{
        rusService.postComment(comment);
        return "redirect:entryView/"+comment.getEntryId();
    }
}
}

Answer 1

The display of errors in <form:errors path="author"/> works like this:

• During validation/binding, the Errors are saved as an attribute in the HttpServletResponse object
• The implementation of this JSP tag calls response.getAttribute(name) to find the Errors instance to display

When you use redirect:url, you are instructing Spring to send a 302 Found to the client’s browser to force the browser to make a second request, to the new URL.

Since the redirected-to page is operating with a different set of request/response objects, the original Errors is lost.

The simplest way to pass “errors” to a page you want to redirect to in order for the new page to display it would be to handle it yourself, by adding a message to the Session object which the second page’s controller can look at (or by passing an argument in the URL).