How to read cookies from HttpResponseMessage?

Question

This is my recent code:

HttpClient authClient = new HttpClient(); authClient.BaseAddress = new Uri("http://localhost:4999/test_db/_session"); authClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); var user = new LoginUserSecretModel { name = userKey, password = loginData.Password, }; HttpResponseMessage authenticationResponse = authClient.PostAsJsonAsync("", user).Result;

Anyway, don't use Result. Use await authClient.PostAsJsonAsync() instead. — abatishchev
– abatishchev, Commented Mar 24, 2015 at 3:58

Daniel · Accepted Answer · 2022-08-17 00:23:22Z

36

The issue I have with many of the answers here is that using CookieContainer uses short-lived HttpClient objects which is not recommended.

Instead, you can simply read the "Set-Cookie" header from the response:

// httpClient is long-lived and comes from a IHttpClientFactory HttpResponseMessage response = await httpClient.GetAsync(uri); IEnumerable<string> cookies = response.Headers.SingleOrDefault(header => header.Key == "Set-Cookie").Value;

If the "Set-Cookie" header is not present, cookies will be null.

edited Aug 17, 2022 at 0:23

answered Feb 21, 2020 at 20:24

Daniel

9,6396 gold badges69 silver badges94 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Chatonne Over a year ago

Once we get the "cookies" string, is there a clean way to obtain a specific cookie value? It feels a bit clunky to have to parse the string to extract the actual cookie value. I assume there's probably be a helper method in .Net to handle it, but most of my researches circle back to CookieContainer which we can't use when reusing our HttpClient instance.

justian17 Over a year ago

Best answer if a person wants to have both a response and the cookies from that response. In my humble opinion, parsing the string is trivial.

cubesnyc Over a year ago

KeyValuePair is not nullable

Hari Over a year ago

Small technicality: KeyValuePair<string, IEnumerable<string>> cannot be tested for null so ?.Value is a syntax error.

Daniel Over a year ago

Thanks @cubesnyc and @Hari, I've fixed the answer and added a line describing what happens if there is no "Set-Cookie" header.

|

RagtimeWilly · Accepted Answer · 2015-03-24 04:53:22Z

Try this:

CookieContainer cookies = new CookieContainer(); HttpClientHandler handler = new HttpClientHandler(); handler.CookieContainer = cookies; HttpClient authClient = new HttpClient(handler); var uri = new Uri("http://localhost:4999/test_db/_session"); authClient.BaseAddress = uri; authClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json")); var user = new LoginUserSecretModel { name = userKey, password = loginData.Password, }; HttpResponseMessage authenticationResponse = authClient.PostAsJsonAsync("", user).Result; var responseCookies = cookies.GetCookies(uri).Cast<Cookie>();

thank you for your answer .... but "cookie" count was 0 and nothing containing when i get HttpResponseMassage.
yes i already set, i found the cookies are in authenticationResponse.headers.
Are the cookies secure? See here: stackoverflow.com/questions/14681144/…
Also, if you are using HttpClient as a shared instance for many parallel requests (as it is recommended aspnetmonsters.com/2016/08/2016-08-27-httpclientwrong ) , be aware that cookies in the handler might belong to a different parallel response, not the one you just received. Unless you do some locking for every request to avoid such cookie race conditions.

Alper Ebicoglu · Accepted Answer · 2018-08-10 13:01:15Z

This is what you need to get a list of cookies;

 private async Task<List<Cookie>> GetCookies(string url, string cookieName) { var cookieContainer = new CookieContainer(); var uri = new Uri(url); using (var httpClientHandler = new HttpClientHandler { CookieContainer = cookieContainer }) { using (var httpClient = new HttpClient(httpClientHandler)) { await httpClient.GetAsync(uri); List<Cookie> cookies = cookieContainer.GetCookies(uri).Cast<Cookie>().ToList(); return cookies; } } }

and if you need only one cookie value here's how

 private async Task<string> GetCookieValue(string url) { var cookieContainer = new CookieContainer(); var uri = new Uri(url); using (var httpClientHandler = new HttpClientHandler { CookieContainer = cookieContainer }) { using (var httpClient = new HttpClient(httpClientHandler)) { await httpClient.GetAsync(uri); var cookie = cookieContainer.GetCookies(uri).Cast<Cookie>().FirstOrDefault(x => x.Name == cookieName); return cookie?.Value; } } }

MarioVW · Accepted Answer · 2022-01-03 09:50:14Z

Building on top of Daniel's answer and this answer to another question, this would be an easy way to read the cookies from an HTTP response.

// httpClient is long-lived and comes from a IHttpClientFactory HttpResponseMessage response = await httpClient.GetAsync(uri); CookieContainer cookies = new CookieContainer(); foreach (var cookieHeader in response.Headers.GetValues("Set-Cookie")) cookies.SetCookies(uri, cookieHeader); string cookieValue = cookies.GetCookies(uri).FirstOrDefault(c => c.Name == "MyCookie")?.Value;

This worked better for me because I have a shared HttpClient instance and didn't need to work with cookies on all of the endpoints.

Collectives™ on Stack Overflow

How to read cookies from HttpResponseMessage?

4 Answers 4

6 Comments

6 Comments

Comments

1 Comment

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

6 Comments

6 Comments

Comments

1 Comment

Linked

Related