android - Volley response headers

Question

I try to use volley for http request. I tried a request on postman and the response headers are below :

1. Content-Encoding →gzip
2. Content-Length →153
3. Content-Type →application/json; charset=utf-8
4. Date →Fri, 30 Jun 2017 13:36:10 GMT
5. ETag →W/"23-E742p6pP4kakmVh3lok1ww"
6. Server →Microsoft-IIS/8.0
7. Vary→X-HTTP-Method-Override, Accept-Encoding,Accept-Encoding
8. X-Powered-By →Express, ASP.NET

Volley adds some extra keys and removes Content-Length and Content-Encoding key. I write keys and values on parseNetworkResponse function. Response headers are below :

Content-Type : application/json; charset=utf-8 Date : Fri, 30 Jun 2017 09:05:23 GMT ETag : W/"23-E742p6pP4kakmVh3lok1ww" Server : Microsoft-IIS/8.0 Set-Cookie : ARRAffinity=16d81073e15abb17d2faba962adb6504734210ff2b9ff1ddfa770750ac7752e2;Path=/;xxx.net Vary : X-HTTP-Method-Override, Accept-Encoding,Accept-Encoding X-Android-Received-Millis : 1498813523832 X-Android-Response-Source : NETWORK 200 X-Android-Selected-Protocol : http/1.1 X-Android-Sent-Millis : 1498813523632 X-Powered-By : Express

Why does it change content? How can I get Content-Length and Content-Encoding ?

Answer 1

if you are using the java.net.HttpURLConnection and the getHeaderFieldKey method, then do not forget to check the 0th element from the header according to the API reference :

Some implementations may treat the 0th header field as special, ie as the status line returned by the HTTP server. In this case, getHeaderField(0) returns the status line , but getHeaderFieldKey(0) returns null.