RestTemplate client with cookies

RestTemplate has a method in which you can define Interface ResponseExtractor<T>, this interface is used to obtain the headers of the response, once you have them you could send it back using HttpEntity and added again.

 .add("Cookie", "SERVERID=c52");

Try something like this.

String cookieHeader = null;

new ResponseExtractor<T>(){
      T extractData(ClientHttpResponse response) {
        response.getHeaders();
      }
}

Then

  HttpHeaders headers = new HttpHeaders();
  headers.add("Cookie", cookieHeader );

  ResponseEntity<byte[]> response = restTemplate.exchange("http://example.com/file/123",
      GET,
      new HttpEntity<String>(headers),
      byte[].class);

Also read this post

I've solved the problem by creating an interceptor which stores a cookie and puts it in next requests.

public class StatefulRestTemplateInterceptor implements ClientHttpRequestInterceptor {
    private String cookie;

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        if (cookie != null) {
            request.getHeaders().add(HttpHeaders.COOKIE, cookie);
        }
        ClientHttpResponse response = execution.execute(request, body);

        if (cookie == null) {
            cookie = response.getHeaders().getFirst(HttpHeaders.SET_COOKIE);
        }
        return response;
    }
}

Set the interceptor for your RestTemplate:

@Bean
public RestTemplate restTemplate(RestTemplateBuilder templateBuilder) {
    return templateBuilder
            .requestFactory(new BufferingClientHttpRequestFactory(new HttpComponentsClientHttpRequestFactory()))
            .interceptors(new StatefulRestTemplateInterceptor())
            .build();
}