获取 ASP.NET MVC 5 Web API 令牌有时会失败

Posted 2023-03-30

【中文标题】获取 ASP.NET MVC 5 Web API 令牌有时会失败

【英文标题】：Get ASP.NET MVC5 WebAPI token fails sometimes

【发布时间】：2016-08-24 13:19:41

【问题描述】：

获取 ASP.NET MVC5 WebAPI 令牌有时会失败

代码

string GetAPITokenSync(string username, string password, string apiBaseUri)
        
            var token = string.Empty;

            using (var client = new HttpClient())
            
                client.BaseAddress = new Uri(apiBaseUri);
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                client.Timeout = TimeSpan.FromSeconds(60);  

                //setup login data
                var formContent = new FormUrlEncodedContent(new[]
                
                 new KeyValuePair<string, string>("grant_type", "password"),
                 new KeyValuePair<string, string>("username", username),
                 new KeyValuePair<string, string>("password", password),
                 );

                //send request               
                Task t = Task.Run(() =>
                
                    HttpResponseMessage responseMessage = client.PostAsync("/Token", formContent).Result;
                    var responseJson = responseMessage.Content.ReadAsStringAsync().Result;
                    var jObject = JObject.Parse(responseJson);
                    token = jObject.GetValue("access_token").ToString();
                );

                t.Wait();
                t.Dispose();
                t = null;
                GC.Collect();

                return token;
            
        

错误

发生了一个或多个错误。 ---> System.AggregateException：一个或 发生了更多错误。 ---> System.Threading.Tasks.TaskCanceledException：任务已取消。 --- 内部异常堆栈跟踪结束 --- 在 System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceled 异常）在 System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at System.Threading.Tasks.Task1.get_Result()

WebAPi 登录方式默认没有变化。

[HttpPost]
[AllowAnonymous]
[Route("Login")]
public HttpResponseMessage Login(string username, string password)
    
        try
        
            var identityUser = UserManager.Find(username, password);

            if (identityUser != null)
            
                var identity = new ClaimsIdentity(Startup.OAuthOptions.AuthenticationType);
                identity.AddClaim(new Claim(ClaimTypes.Name, username));

                AuthenticationTicket ticket = new AuthenticationTicket(identity, new AuthenticationProperties());
                var currentUtc = new SystemClock().UtcNow;
                ticket.Properties.IssuedUtc = currentUtc;
                ticket.Properties.ExpiresUtc = currentUtc.Add(TimeSpan.FromMinutes(1440));

                var token = Startup.OAuthOptions.AccessTokenFormat.Protect(ticket);

                var response = new HttpResponseMessage(HttpStatusCode.OK)
                
                    Content = new ObjectContent<object>(new
                    
                        UserName = username,
                        ExternalAccessToken = token
                    , Configuration.Formatters.JsonFormatter)
                ;

                return response;


            
        
        catch (Exception)
        
        

        return new HttpResponseMessage(HttpStatusCode.BadRequest);
    

Startup 类默认没有变化

 public partial class Startup
    
        public static OAuthAuthorizationServerOptions OAuthOptions  get; private set; 

        public static string PublicClientId  get; private set; 


        public void ConfigureAuth(IAppBuilder app)
        
            // Configure the db context and user manager to use a single instance per request
            app.CreatePerOwinContext(ApplicationDbContext.Create);
            app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);

            // Enable the application to use a cookie to store information for the signed in user
            // and to use a cookie to temporarily store information about a user logging in with a third party login provider
            app.UseCookieAuthentication(new CookieAuthenticationOptions());
            app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);

            // Configure the application for OAuth based flow
            PublicClientId = "self";
            OAuthOptions = new OAuthAuthorizationServerOptions
            
                TokenEndpointPath = new PathString("/Token"),
                Provider = new ApplicationOAuthProvider(PublicClientId),
                AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
                // In production mode set AllowInsecureHttp = false
                AllowInsecureHttp = true
            ;

            // Enable the application to use bearer tokens to authenticate users
            app.UseOAuthBearerTokens(OAuthOptions);
        
    

有什么线索吗？

【问题讨论】：

不是超时了吗？ 60秒后？你为什么要在一个任务上运行 Post？然后阻塞你的调用线程等待任务完成？

@BrunoGarcia 我猜 60 秒就可以拿到令牌了。请提出一些需要考虑的建议...谢谢！

我的意思是：问题不是因为您的通话超时了吗？是因为它无法到达服务器还是需要太长时间（超过 60 秒）才能完成？特别是如果它有时只会失败

@BrunoGarcia 它应该可以工作......我也会尝试这个解决方案***.com/questions/30656795/…

@Dimi 我认为您没有回答是否超时的问题。是吗？

【参考方案1】：

很难确定，但阻止 HttpClient 调用的方式无济于事。 HttpClient 是一个仅异步库；您可能会遇到死锁情况。我建议摆脱所有.Results 和.Wait()s 并使用async/await 异步编写所有内容。而且您的 Task.Run 没有取得任何成果，所以应该去。

我知道这是从控制台应用移植过来的 Topshelf 应用。我对 Topshelf 不是很熟悉，但我认为，就像控制台应用程序一样，您需要在 某处 进行屏蔽，否则您的应用程序将直接退出。执行此操作的位置位于最顶部 - 应用程序的入口点。

这演示了该模式，并重写了您的 GetApiToken 方法：

// app entry point - the only place you should block
void Main()

    MainAsync().Wait();


// the "real" starting point of your app logic. do everything async from here on
async Task MainAsync()

    ...
    var token = await GetApiTokenAsync(username, password, apiBaseUri);
    ...


async Task<string> GetApiTokenAsync(string username, string password, string apiBaseUri)

    var token = string.Empty;

    using (var client = new HttpClient())
    
        client.BaseAddress = new Uri(apiBaseUri);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        client.Timeout = TimeSpan.FromSeconds(60);  

        //setup login data
        var formContent = new FormUrlEncodedContent(new[]
        
         new KeyValuePair<string, string>("grant_type", "password"),
         new KeyValuePair<string, string>("username", username),
         new KeyValuePair<string, string>("password", password),
         );

        //send request               
        HttpResponseMessage responseMessage = await client.PostAsync("/Token", formContent);
        var responseJson = await responseMessage.Content.ReadAsStringAsync();
        var jObject = JObject.Parse(responseJson);
        token = jObject.GetValue("access_token").ToString();

        return token;