Model generation for manually entered page in Spring framework

Question

I have to extend some Spring web application, but I'm not very familiar with the framework (however, I have some experience with few other frameworks). I can see that there is "ModelAndView" concept used by the framework. Controller returns both: a model and a view from onSubmit() method. But what to do if a model have to be generated for a page entered manually (user enters the page address to the browser address bar, instead of submitting a form). In such a case there is no onSubmit() call, so a model isn't prepared.

I thought of (ab)using formBackingObject() method of BaseFormController class, which prepares "command" object. But I don't know how to refer the object in the jsp code. Any hints would be appreciated.

Answer 1

You can configure the supported HTTP methods of the controller with the supportedMethods property. The default values are HEAD, GET and POST. If the same parameters are sent with a GET request (there are some restrictions on what can be transmitted) there should be no difference from the controller perspective.

It has to be noted that the HTTP methods have a semantic that should not be broken: get to retrieve (without changes), post to manipulate etc.

Answer 2

The proper method to override to provide model data for the "initial" view is referenceData(). As you can see in the Javadoc, there are two overloads of this method, depending on what you need to do.

Create a reference data map for the given request and command, consisting of bean name/bean instance pairs as expected by ModelAndView.

The default implementation delegates to referenceData(HttpServletRequest). Subclasses can override this to set reference data used in the view.