REST Controller

Our Spring MVC controllers dealt with GET requests for views, as well as POST requests from forms.

@RequestMapping(path = "films.do", method = RequestMethod.GET)
public ModelAndView index() {
  ModelAndView mv = new ModelAndView("index.jsp");
  mv.addObject("films", filmDAO.index());
  return mv;
}

• Spring provides shortcuts for @RequestMapping:

@GetMapping(path = "films.do") // or just @GetMapping("films.do")
public ModelAndView index() { ...

Because REST controllers deal with the full variety of HTTP verbs, these shortcuts are more convenient.

@Controller
public class BookController {
  @GetMapping("api/books")
  @ResponseBody
  public List<Book> allBooks() { ... }

  @PostMapping("api/books")
  @ResponseBody
  public Book addBook(@RequestBody Book book) { ... }

  @PutMapping("api/books/{bookId}")
  @ResponseBody
  public Book replaceBook(@PathVariable Integer bookId, @RequestBody Book book) { ... }

  @DeleteMapping("api/books/{bookId}")
  @ResponseBody
  public void removeBook(@PathVariable("bookId") Integer id) { ... }

  // ...
}

You can put both @RequestMapping and @ResponseBody above a controller class declaration to precede every endpoint method with these annotations.

@RequestMapping("api")
@ResponseBody
@Controller
public class BookController {
  @GetMapping("books")
  public List<Book> allBooks() { ... }

  @PostMapping("books")
  public Book addBook(@RequestBody Book book) { ... }
}

• The allBooks method will be automatically mapped to "api/books".

@RestController implies both @Controller and @ResponseBody:

@RequestMapping("api")
@RestController
public class BookController {
  @GetMapping("books")
  public List<Book> allBooks() { ... }

Practice Exercise

Never use Controller or RestController as a class name, e.g. public class RestController or public class Controller. Creating classes with these names would override the Spring implementations and you would lose access to their respective annotations.

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