CODEWITHSUNDEEP
javaspringspring-mvc
sparrow
sparrow

Reputation: 1875

Request Header is getting as null in spring mvc

I am having two mapping methods in my controller. one is redirecting to other. Before redirecting I'm setting a header in response. But I getting the request header as null. These are my methods in controller. both are in same controller.

@RequestMapping(value="/testStart", method=RequestMethod.POST)
        public String testStart(HttpServletRequest request, HttpServletResponse response){
            String token = "126712810-1289291":

            response.addHeader("authToken", token);

            return "redirect:/test";
        }
@RequestMapping(value="/test", method={ RequestMethod.POST, RequestMethod.GET })
    public String getTestPage(Model model, HttpServletRequest request, HttpServletResponse response){

        String token = request.getHeader("authToken");
        System.out.println(token);  //prints null
        model.addAttribute("Testtoken", token);
        System.out.println("Test page about to load ..");
        return "test";

}

I'm using postman client to test this api. It is hitting the url and redirecting to other url. but the header is null. I don't know what's wrong. can any one help me to figure this out? Thanks

Upvotes: 3

Views: 8504

Answers (2)

Ömer Erden
Ömer Erden

Reputation: 8793

With Redirect method web app tells browser to load the page which you want to redirect. So this makes new http request from browser, the original requests are not reachable at this moment.

So your problem can be solved with Forward method. Web app forwards all request data to another handler method internally

return "forward:/test";

Additionally , please change your 

String token = request.getHeader("authToken");

with 

String token = response.getHeader("authToken");

because you are adding your authToken to the response object.(from comments HttpServletResponse -> getHeader(String name) works since Servlet 3.0)

EDIT :

this code will be your complete solution "/test" method supports forwarded reuqest and also supports request from browser. (You want to get token info from request becuase you want to call /test method without forwarding, so it works in this way, but when forwarding you cant add header so you tried to add in response and get it from request but that doesnt work in that way so you need to resolve token according to dispatcher's type so check the code ) 

@RequestMapping(value="/testStart", method=RequestMethod.POST)
public String testStart(HttpServletRequest request, HttpServletResponse response){
    String token = "126712810-1289291";

    request.setAttribute("authToken", token);

    return "forward:/test";
}

@RequestMapping(value="/test", method={ RequestMethod.POST, RequestMethod.GET })
public String getTestPage(Model model, HttpServletRequest request, HttpServletResponse response)
{   

    //-----------------
    //resolving token
    String token = null;
    DispatcherType type = request.getDispatcherType();

    if(type == DispatcherType.FORWARD)
    {
        token = (String) request.getAttribute("authToken");
    }
    else if(type == DispatcherType.REQUEST)
    {
        token = (String) request.getHeader("authToken");
    }
    //-----------------

    System.out.println(token);  //prints the value
    model.addAttribute("Testtoken", token);
    System.out.println("Test page about to load ..");
    return "test";
}

Upvotes: 2

Prasanna Kumar H A
Prasanna Kumar H A

Reputation: 3431

Use RedirectAttributes to pass parameters with redirect URL:

@RequestMapping(value="/test1", method=GET)
public String test(RedirectAttributes redirectAttributes){
   redirectAttributes.addAttribute("authToken", "val");
   return "redirect:/test";
}

or if you can use forward:/test you can go with request.setAttribute and request.getAttribute

Still if you want to add in header then use RestTemplate and HTTPHeaders and get the response String

Upvotes: 1

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