Redirect to an external URL from controller action in Spring MVC

You can do it with two ways.

First:

@RequestMapping(value = "/redirect", method = RequestMethod.GET)
public void method(HttpServletResponse httpServletResponse) {
    httpServletResponse.setHeader("Location", projectUrl);
    httpServletResponse.setStatus(302);
}

Second:

@RequestMapping(value = "/redirect", method = RequestMethod.GET)
public ModelAndView method() {
    return new ModelAndView("redirect:" + projectUrl);
}

You can use the RedirectView. Copied from the JavaDoc:

View that redirects to an absolute, context relative, or current request relative URL

Example:

@RequestMapping("/to-be-redirected")
public RedirectView localRedirect() {
    RedirectView redirectView = new RedirectView();
    redirectView.setUrl("http://www.yahoo.com");
    return redirectView;
}

You can also use a ResponseEntity, e.g.

@RequestMapping("/to-be-redirected")
public ResponseEntity<Object> redirectToExternalUrl() throws URISyntaxException {
    URI yahoo = new URI("http://www.yahoo.com");
    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.setLocation(yahoo);
    return new ResponseEntity<>(httpHeaders, HttpStatus.SEE_OTHER);
}

And of course, return redirect:http://www.yahoo.com as mentioned by others.

You can do this in pretty concise way using ResponseEntity like this:

  @GetMapping
  ResponseEntity<Void> redirect() {
    return ResponseEntity.status(HttpStatus.FOUND)
        .location(URI.create("http://www.yahoo.com"))
        .build();
  }

Looking into the actual implementation of UrlBasedViewResolver and RedirectView the redirect will always be contextRelative if your redirect target starts with /. So also sending a //yahoo.com/path/to/resource wouldn't help to get a protocol relative redirect.

So to achieve what you are trying you could do something like:

@RequestMapping(method = RequestMethod.POST)
public String processForm(HttpServletRequest request, LoginForm loginForm, 
                          BindingResult result, ModelMap model) 
{
    String redirectUrl = request.getScheme() + "://www.yahoo.com";
    return "redirect:" + redirectUrl;
}

Another way to do it is just to use the sendRedirect method:

@RequestMapping(
    value = "/",
    method = RequestMethod.GET)
public void redirectToTwitter(HttpServletResponse httpServletResponse) throws IOException {
    httpServletResponse.sendRedirect("https://twitter.com");
}

For me works fine:

@RequestMapping (value = "/{id}", method = RequestMethod.GET)
public ResponseEntity<Object> redirectToExternalUrl() throws URISyntaxException {
    URI uri = new URI("http://www.google.com");
    HttpHeaders httpHeaders = new HttpHeaders();
    httpHeaders.setLocation(uri);
    return new ResponseEntity<>(httpHeaders, HttpStatus.SEE_OTHER);
}

For external url you have to use "http://www.yahoo.com" as the redirect url.

This is explained in the redirect: prefix of Spring reference documentation.

redirect:/myapp/some/resource

will redirect relative to the current Servlet context, while a name such as

redirect:http://myhost.com/some/arbitrary/path

will redirect to an absolute URL

Did you try RedirectView where you can provide the contextRelative parameter?

This works for me, and solved "Response to preflight request doesn't pass access control check ..." issue.

Controller

    RedirectView doRedirect(HttpServletRequest request){

        String orgUrl = request.getRequestURL()
        String redirectUrl = orgUrl.replaceAll(".*/test/","http://xxxx.com/test/")

        RedirectView redirectView = new RedirectView()
        redirectView.setUrl(redirectUrl)
        redirectView.setStatusCode(HttpStatus.TEMPORARY_REDIRECT)
        return redirectView
    }

and enable securty

@EnableWebSecurity
class SecurityConfigurer extends WebSecurityConfigurerAdapter{
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and().csrf().disable()
    }
}

In short "redirect://yahoo.com" will lend you to yahoo.com.

where as "redirect:yahoo.com" will lend you your-context/yahoo.com ie for ex- localhost:8080/yahoo.com