Spring 3.1 M2: Spring MVC Enhancements

Programming Model Improvements

This is the list of programming model improvements introduced in the new @MVC support classes.

1. Declared @PathVariable arguments are now automatically added to the model. For example this:
@RequestMapping("/develop/apps/edit/{slug}") public String editForm(@PathVariable String slug, Model model) { model.addAttribute("slug", slug); // ... }
is replaced by:
@RequestMapping("/develop/apps/edit/{slug}") public String editForm(@PathVariable String slug, Model model) { // model contains "slug" variable }


2. Redirect strings support URI templates expanded with variables from the model (including declared @PathVariables). For example this:
@RequestMapping( value="/groups/{group}/events/{year}/{month}/{slug}/rooms", method=RequestMethod.POST) public String createRoom( @PathVariable String group, @PathVariable Integer year, @PathVariable Integer month, @PathVariable String slug) { // ... return "redirect:/groups/" + group + "/events/" + year + "/" + month + "/" + slug; }
is replaced by:
@RequestMapping( value="/groups/{group}/events/{year}/{month}/{slug}/rooms", method=RequestMethod.POST) public String createRoom( @PathVariable String group, @PathVariable Integer year, @PathVariable Integer month, @PathVariable String slug) { // ... return "redirect:/groups/{group}/events/{year}/{month}/{slug}"; }


3. URI template variables are supported in data binding. For example this:
@RequestMapping("/people/{firstName}/{lastName}/SSN") public String find(Person person, @PathVariable String firstName, @PathVariable String lastName) { person.setFirstName(firstName); person.setLastName(lastName); // ... }
is replaced by:
@RequestMapping("/people/{firstName}/{lastName}/SSN") public String search(Person person) { // person.getFirstName() and person.getLastName() are populated // ... }


4. Consumable and producible media types can be specified via @RequestMapping. For example this:
@RequestMapping(value="/pets", headers="Content-Type=application/json") public void addPet(@RequestBody Pet pet, Model model) { // ... }
is replaced by:
@RequestMapping(value="/pets", consumes="application/json") public void addPet(@RequestBody Pet pet, Model model) { // ... }
Besides being shorter the above returns NOT_ACCEPTABLE (406) if the URL matches but the input media type doesn't.


5. For producible media types this:
@Controller @RequestMapping(value = "/pets/{petId}", headers="Accept=application/json") @ResponseBody public Pet getPet(@PathVariable String petId, Model model) { // ... }
is replaced by:
@Controller @RequestMapping(value = "/pets/{petId}", produces="application/json") @ResponseBody public Pet getPet(@PathVariable String petId, Model model) { // ... }
The above returns a NOT_SUPPORTED_MEDIA_TYPE (415) if the URL matches but the acceptable media type doesn't.