Controllers

At class level

@Controller
@RequestMapping("/appointments")
public class AppointmentsController {

At method level for HTTP GET

@GetMapping(path = "/{day}")
public Map<String, Appointment> getForDay(@PathVariable @DateTimeFormat(iso=ISO.DATE) Date day, Model model) {

Getting request parameter

@RequestMapping(method = RequestMethod.GET)
public String setupForm(@RequestParam("petId", required=false) int petId, ModelMap model) {

You can use consumes and/or produces to control data type

@RequestMapping(path = "/pets", method = RequestMethod.POST, consumes="application/json", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
@ResponseBoddy
public Pet addPet(@RequestBody Pet pet, Model model) {

NB: You can avoid using ResponseBody if you use @RestController instead of @Controller

Handling cookies

@RequestMapping("/displayInfo")
public void displayHeaderInfo(@CookieValue("JSESSIONID") String cookie)

Handling HTTP headers

@RequestMapping("/displayHeaderInfo")
public void displayHeaderInfo(@RequestHeader("Accept-Encoding") String encoding, @RequestHeader("Keep-Alive") long keepAlive) {

Using ModelAttribute and SessionAttributes

Full example:

@Controller @RequestMapping("/trades")
@SessionAttributes("visitor")
public class TradeController {
    @RequestMapping("/**")
    public String handleRequestById (@ModelAttribute("visitor") Visitor visitor,Model model, HttpServletRequest request) {
        model.addAttribute("msg", "trades request, serving page " + request.getRequestURI());
        visitor.addPageVisited(request.getRequestURI());
        return "traders-page";
    }
    @ModelAttribute("visitor")
    public Visitor getVisitor (HttpServletRequest request) {
        return new Visitor(request.getRemoteAddr());
    }
}

Handling exceptions

@ControllerAdvice
public class ErrorController {
  ...
  @ExceptionHandler(AccessDeniedException.class)
  @ResponseBody
  @ResponseStatus(HttpStatus.FORBIDDEN)
  public ErrorResponse accessDenied(AccessDeniedException e) {
  }
}

Asynchronous request processing

It is possible to use the Servlet 3.0 asynchronous request processing feature in Spring:

@RequestMapping(method=RequestMethod.POST)
public Callable<String> processUpload(final MultipartFile file) {
  return new Callable<String>() {
      public String call() throws Exception {
        // ...
        return "someView";
        }
  }
}

Or using DefferedResult

@RequestMapping("/quotes")
@ResponseBody
public DeferredResult<String> quotes() {
  DeferredResult<String> deferredResult = new DeferredResult<String>();
  // Save the deferredResult somewhere..
  return deferredResult;
}
// In some other thread...
deferredResult.setResult(data);