Header is not able to be extracted from HttpServletRequest

Sudip Bolakhe :

I am working on micro-service architecture. I have 3 different application with a different domain name. Suppose application 1 has an API:

 "/app/foo-bar"

This API is called from some service of application 2, the service is also triggered by some API. This API can also be called from application 3.

What I need now is, when the API is called in application 1, I want to find out from which application it was called. ( domain name of application 2 or application 3)

I tried this :

request.getHeader("referer");

But this returns me null

Is there any way to solve this?

Md. Sajedul Karim :

You have to set header during call to the API.Also you have to get header in that API for origin of caller.

SET header during API call: app/foo-bar

RestTemplate restTemplate = new RestTemplate();

HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
headers.setContentType(MediaType.APPLICATION_JSON);
headers.set("referer", "APP_1");

HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);

Get Header In API

@RequestMapping(value = "/app/foo-bar")
    public String serveRest(@RequestBody String body, @RequestHeader HttpHeaders headers) {


        List<String> parameters = headers.get("parameters");

        String referer = null;
        for (String header : parameters) {
            if (header.equals("referer")) {
                referer = header;
            }
        }
        System.out.println(referer);

        return referer;
    }

Here is the imports:

import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;