RedirectView isEligibleValue exposing too much?

[davoz]

Hi all,

I guess it is by design, but I noticed a change in RedirectView between 2.5.x and 3.0.0.RELEASE which seems a bit unusual.

In 2.5.x RedirectView only exposed primitives/wrappers in the url of the redirected view ala

protected boolean isEligibleProperty(String key, Object value) {
    return .... ClassUtils.isPrimitiveOrWrapper(value.getClass());
}

In 3.0.0.RELEASE, this has changed to

protected boolean isEligibleProperty(String key, Object value) {
    return .... BeanUtils.isSimpleValueType(value.getClass());
}

... which includes things like enums, dates, uris, urls, locales, classes etc.

I was wondering why this is now so? Under what circumstances would the default behaviour make sense?

I ask because, typically we expose reference data like enums for a form via @ModelAttribute. eg

@ModelAttribute
public Gender[] getGenders() {
    return Gender.values(); // Gender is an enum
}

When a form submission succeeds, we redirect to the success view. eg

@RequestMapping(...)
public String saveCustomer(...) {
    ...
    return "redirect:/customers";
}

The RedirectView now generates urls like so:

/customers?genders=MALE&genders=FEMALE

Also, I'm using the RedirectView as part of the InternalResourceViewResolver, whose behaviour is from UrlBasedViewResolver#createView(...) and that doesn't expose any configurable attribute to:

(a) create a subclass of RedirectView instead or
(b) call RedirectView#setExposeModelAttributes(false)

Can someone more familiar with the design of Spring MVC suggest why this new default behaviour makes sense? And how I can achieve what I want easily without sub-classing InternalResourceViewResolver and/or RedirectView or returning a View from my controller instead of a String.


thanks,
dave

[davoz]

Has nobody encountered this issue? Am I using Spring MVC 3.0 incorrectly?

dave

[davoz]

I ended up sub-classing InternalResourceViewResolver like so:

public class StrictInternalResourceViewResolver extends InternalResourceViewResolver {

    boolean exposeModelAttributes = false;

    @Override
    protected View createView(String viewName, Locale locale) throws Exception {
        View view = super.createView(viewName, locale);
        if (view instanceof RedirectView) {
            ((RedirectView) view).setExposeModelAttributes(exposeModelAttributes);
        }
        return view;
    }

    public boolean isExposeModelAttributes() {
        return exposeModelAttributes;
    }

    public void setExposeModelAttributes(boolean exposeModelAttributes) {
        this.exposeModelAttributes = exposeModelAttributes;
    }

}

By default, it won't expose model attributes for RedirectViews. I then just need to ensure when constructing "redirect:/customers" that I explicitly include the request parameters. eg "redirect:/customers?lastName=Smith&offset=20" etc

[Goll97]

this looks good but, here is a problem as per other post: caching of the redirect view
this is regarding you last comment, construction your own redirect parameters. Unless this is already fixed.


http://forum.springsource.org/showthread.php?t=86633
http://forum.springsource.org/showthread.php?t=75324

This isn't a good sample imho (i'll register a JIRA issue for it) because now there are issues with the caching of the RedirectView, each redirect will now lead to a cached instance of RedirectView because the key is the URL and now it includes the id, if you put it in the model it would be simple /owners and spring would take care of the rest.