Struggling trying to get cookie out of response with HttpClient in .net 4.5
I've got the following code that works successfully. I can't figure out how to get the cookie out of the response. My goal is that I want to be able to set cookies in the request and get cookies out of the response. Thoughts?
private async Task<string> Login(string username, string password)
{
try
{
string url = "http://app.agelessemail.com/account/login/";
Uri address = new Uri(url);
var postData = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("username", username),
new KeyValuePair<string, string>("password ", password)
};
HttpContent content = new FormUrlEncodedContent(postData);
var cookieJar = new CookieContainer();
var handler = new HttpClientHandler
{
CookieContainer = cookieJar,
UseCookies = true,
UseDefaultCredentials = false
};
var client = new HttpClient(handler)
{
BaseAddress = address
};
HttpResponseMessage response = await client.PostAsync(url,content);
response.EnsureSuccessStatusCode();
string body = await response.Content.ReadAsStringAsync();
return body;
}
catch (Exception e)
{
return e.ToString();
}
}
Here is the complete answer:
HttpResponseMessage response = await client.PostAsync(url,content);
response.EnsureSuccessStatusCode();
Uri uri = new Uri(UrlBase);
var responseCookies = cookieJar.GetCookies(uri);
foreach (Cookie cookie in responseCookies)
{
string cookieName = cookie.Name;
string cookieValue = cookie.Value;
}
To add cookies to a request, populate the cookie container before the request with CookieContainer.Add(uri, cookie). After the request is made the cookie container will automatically be populated with all the cookies from the response. You can then call GetCookies() to retreive them.
CookieContainer cookies = new CookieContainer();
HttpClientHandler handler = new HttpClientHandler();
handler.CookieContainer = cookies;
HttpClient client = new HttpClient(handler);
HttpResponseMessage response = client.GetAsync("http://google.com").Result;
Uri uri = new Uri("http://google.com");
IEnumerable<Cookie> responseCookies = cookies.GetCookies(uri).Cast<Cookie>();
foreach (Cookie cookie in responseCookies)
Console.WriteLine(cookie.Name + ": " + cookie.Value);
Console.ReadLine();
There's alternative if you don't have access to the HttpClient and can't inject the CookieContainer. This works in .NET Core 2.2:
private string GetCookie(HttpResponseMessage message)
{
message.Headers.TryGetValues("Set-Cookie", out var setCookie);
var setCookieString = setCookie.Single();
var cookieTokens = setCookieString.Split(';');
var firstCookie = cookieTokens.FirstOrDefault();
var keyValueTokens = firstCookie.Split('=');
var valueString = keyValueTokens[1];
var cookieValue = HttpUtility.UrlDecode(valueString);
return cookieValue;
}
var setCookieString = setCookie.Single(); should probably be changed as it is quite possible for setCookie to have multiple values and thus cause an exception to be thrown. I ended up adding a parameter string cookieName and then used setCookie.Single(x => x.StartsWith(cookieName));. This does still assume the requested cookie exists.
Set-Cookie header does have multiple values, they are separated by a semicolon(;), but normally there should be only a single Set-Cookie header
You can easily get a cookie value with the given URL.
private async Task<string> GetCookieValue(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);
var cookie = cookieContainer.GetCookies(uri).Cast<Cookie>().FirstOrDefault(x => x.Name == cookieName);
return cookie?.Value;
}
}
}
Not in every case you can add httpClientHandler to httpClient. For example, when you use integration tests testServer.CreateClient() or inject httpClient from IHttpClientFactory. So, I have simply read values from header.
public static List<Cookie> GetCookies(this HttpResponseMessage message)
{
message.Headers.TryGetValues("Set-Cookie", out var cookiesHeader);
var cookies = cookiesHeader.Select(cookieString => CreateCookie(cookieString)).ToList();
return cookies;
}
private static Cookie CreateCookie(string cookieString)
{
var properties = cookieString.Split(';', StringSplitOptions.TrimEntries);
var name = properties[0].Split("=")[0];
var value = properties[0].Split("=")[1];
var path = properties[2].Replace("path=", "");
var cookie = new Cookie(name, value, path)
{
Secure = properties.Contains("secure"),
HttpOnly = properties.Contains("httponly"),
Expires = DateTime.Parse(properties[1].Replace("expires=", ""))
};
return cookie;
}
CreateCookie method may be modified to exactly match your cookie properties.
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httpclientis built from the httpclient factory ? i.e builder method added to services.AddHttpClient