Spring MVC @RestController and redirect

Question

I have a REST endpoint implemented with Spring MVC @RestController. Sometime, depends on input parameters in my controller I need to send http redirect on client.

Is it possible with Spring MVC @RestController and if so, could you please show an example ?

Answer 1

Add an HttpServletResponse parameter to your Handler Method then call response.sendRedirect("some-url");

Something like:

@RestController
public class FooController {

  @RequestMapping("/foo")
  void handleFoo(HttpServletResponse response) throws IOException {
    response.sendRedirect("some-url");
  }

}

Answer 2

To avoid any direct dependency on HttpServletRequest or HttpServletResponse I suggest a "pure Spring" implementation returning a ResponseEntity like this:

HttpHeaders headers = new HttpHeaders();
headers.setLocation(URI.create(newUrl));
return new ResponseEntity<>(headers, HttpStatus.MOVED_PERMANENTLY);

If your method always returns a redirect, use ResponseEntity<Void>, otherwise whatever is returned normally as generic type.

Answer 3

Came across this question and was surprised that no-one mentioned RedirectView. I have just tested it, and you can solve this in a clean 100% spring way with:

@RestController
public class FooController {

    @RequestMapping("/foo")
    public RedirectView handleFoo() {
        return new RedirectView("some-url");
    }
}

Answer 4

redirect means http code 302, which means Found in springMVC.

Here is an util method, which could be placed in some kind of BaseController:

protected ResponseEntity found(HttpServletResponse response, String url) throws IOException { // 302, found, redirect,
    response.sendRedirect(url);
    return null;
}

---

But sometimes might want to return http code 301 instead, which means moved permanently.

In that case, here is the util method:

protected ResponseEntity movedPermanently(HttpServletResponse response, String url) { // 301, moved permanently,
    return ResponseEntity.status(HttpStatus.MOVED_PERMANENTLY).header(HttpHeaders.LOCATION, url).build();
}

Answer 5

As the redirections are usually needed in a not-straightforward path, I think throwing an exception and handling it later is my favourite solution.

Using a ControllerAdvice

@ControllerAdvice
public class RestResponseEntityExceptionHandler
    extends ResponseEntityExceptionHandler {

  @ExceptionHandler(value = {
      NotLoggedInException.class
  })
  protected ResponseEntity<Object> handleNotLoggedIn(
      final NotLoggedInException ex, final WebRequest request
  ) {
    final String bodyOfResponse = ex.getMessage();

    final HttpHeaders headers = new HttpHeaders();
    headers.add("Location", ex.getRedirectUri());
    return handleExceptionInternal(
        ex, bodyOfResponse,
        headers, HttpStatus.FOUND, request
    );
  }
}

The exception class in my case:

@Getter
public class NotLoggedInException extends RuntimeException {

  private static final long serialVersionUID = -4900004519786666447L;

  String redirectUri;

  public NotLoggedInException(final String message, final String uri) {
    super(message);
    redirectUri = uri;
  }
}

And I trigger it like this:

if (null == remoteUser)
  throw new NotLoggedInException("please log in", LOGIN_URL);

Answer 6

if you @RestController returns an String you can use something like this

return "redirect:/other/controller/";

and this kind of redirect is only for GET request, if you want to use other type of request use HttpServletResponse