我有一个用.NET Core编写的API。我有一个令牌中间件，我有一些问题。
如果我一次向一个客户发送中间件请求，那很好。如果我一次尝试使用多个客户端的中间件，我会收到错误。
据我所知，我认为_userManager每次发出请求时都没有创建新实例，我认为这会导致我的问题。我似乎要么
System.InvalidOperationException：尝试在配置上下文时使用上下文
或
System.ObjectDisposedException：无法访问已处置的对象
我想我注射的UserManager<ApplicationUser>可能是单身人士吗？也许两个请求都试图使用相同的_userManager实例，第一个请求处理它，第二个请求错误？
我对此并不熟悉，所以也许我离开了基地。也许_userManager并不意味着以这种方式使用，或者我可能不正确地注入它。
以下是starup.cs和令牌中间件的一些代码。下面是一些错误日志。
startup.cs的部分内容
public void ConfigureServices(IServiceCollection services)
{
...
services.AddDbContext<ApplicationDbContext>(options =>
{
options.UseNpgsql(Environment.GetEnvironmentVariable("DbConnString"));
});
services.AddIdentity<ApplicationUser, IdentityRole>(o=>
{
o.Password.RequireDigit = false;
o.Password.RequiredLength = 0;
o.Password.RequireLowercase = false;
o.Password.RequireNonAlphanumeric = false;
o.Password.RequireUppercase = false;
o.SignIn.RequireConfirmedEmail = true;
o.User.RequireUniqueEmail = true;
})
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
services.AddAuthentication(o =>
{
o.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
o.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
}).AddJwtBearer(options =>
{
options.TokenValidationParameters = tokenValidationParameters;
});
...
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
...
app.UseJWTTokenProviderMiddleware(Options.Create(jwtOptions));
app.UseAuthentication();
app.UseMvc();
...
}
TokenProviderMiddleware
public class TokenProviderMiddleware
{
private readonly RequestDelegate _next;
private TokenProviderOptions _options;
private UserManager<ApplicationUser> _userManager;
private readonly ILogger<TokenProviderMiddleware> _logger;
public TokenProviderMiddleware(RequestDelegate next, IOptions<TokenProviderOptions> options, ILogger<TokenProviderMiddleware> logger)
{
_next = next;
_options = options.Value;
_logger = logger;
}
public async Task Invoke(HttpContext context, UserManager<ApplicationUser> userManager)
{
_userManager = userManager;
if (!context.Request.Path.Equals(_options.Path, StringComparison.Ordinal))
{
await _next(context);
return;
}
if (!context.Request.Method.Equals("POST") || !context.Request.HasFormContentType)
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("Bad Request");
return;
}
ApplicationUser user = null;
string refreshToken;
string accessToken;
if (context.Request.Form["grant_type"].Equals("refresh_token"))
{
refreshToken = context.Request.Form["refresh_token"];
if(String.IsNullOrEmpty(refreshToken))
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("refresh_token not sent");
return;
}
// Check that the refresh_token is valid
// I don't like using exceptions for flow control but it's how ValidateToken works
try
{
ValidateRefreshToken(refreshToken);
}
catch(SecurityTokenInvalidSignatureException ex)
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("refresh_token failed validation");
return;
}
catch(Exception ex)
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("refresh_token failed validation");
return;
}
user = await GetUserAsync(context, "from_refresh_token");
accessToken = await GenerateAccessToken(user);
var response = new
{
access_token = accessToken
};
context.Response.ContentType = "application/json";
await context.Response.WriteAsync(JsonConvert.SerializeObject(response, new JsonSerializerSettings { Formatting = Formatting.Indented }));
return;
}
private async Task<ApplicationUser> GetUserAsync(HttpContext context, string getUserFrom)
{
ApplicationUser user = null;
if(getUserFrom.Equals("from_username_password"))
{
string username = context.Request.Form["username"];
string password = context.Request.Form["password"];
if(String.IsNullOrEmpty(username) || String.IsNullOrEmpty(password))
{
throw new ArgumentException("Username/password not sent");
}
user = await _userManager.FindByNameAsync(username);
var result = _userManager.CheckPasswordAsync(user, password);
if (result.Result == false)
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("Invalid username or password");
}
if(!await _userManager.IsEmailConfirmedAsync(user))
{
context.Response.StatusCode = 400;
await context.Response.WriteAsync("Email address not confirmed");
}
}
else if (getUserFrom.Equals("from_refresh_token"))
{
JwtSecurityToken decodedRefreshToken = new JwtSecurityTokenHandler().ReadJwtToken(context.Request.Form["refresh_token"]);
string uid = decodedRefreshToken.Payload.Claims.FirstOrDefault(x => x.Type == "uid").Value;
user = await _userManager.FindByIdAsync(uid);
}
return user;
}
错误日志
2017-12-02 19:45:27.171 -05:00 [Information] Request starting HTTP/1.1 POST http://0.0.0.0:5000/api/token application/x-www-form-urlencoded 204
2017-12-02 19:45:27.171 -05:00 [Information] Request starting HTTP/1.1 POST http://0.0.0.0:5000/api/token application/x-www-form-urlencoded 204
2017-12-02 19:45:27.171 -05:00 [Debug] "POST" requests are not supported
2017-12-02 19:45:27.171 -05:00 [Debug] "POST" requests are not supported
2017-12-02 19:45:27.171 -05:00 [Debug] The request has an origin header: '"http://0.0.0.0:8080"'.
2017-12-02 19:45:27.171 -05:00 [Debug] The request has an origin header: '"http://0.0.0.0:8080"'.
2017-12-02 19:45:27.171 -05:00 [Information] Policy execution successful.
2017-12-02 19:45:27.172 -05:00 [Information] Policy execution successful.
2017-12-02 19:45:27.172 -05:00 [Debug] Connection id ""0HL9PS1UOQ2DS"", Request id ""0HL9PS1UOQ2DS:000000C7"": started reading request body.
2017-12-02 19:45:27.172 -05:00 [Debug] Connection id ""0HL9PS1UOQ2E0"", Request id ""0HL9PS1UOQ2E0:0000000B"": started reading request body.
2017-12-02 19:45:27.175 -05:00 [Debug] Connection id ""0HL9PS1UOQ2DS"", Request id ""0HL9PS1UOQ2DS:000000C7"": done reading request body.
2017-12-02 19:45:27.175 -05:00 [Debug] Connection id ""0HL9PS1UOQ2E0"", Request id ""0HL9PS1UOQ2E0:0000000B"": done reading request body.
2017-12-02 19:45:27.450 -05:00 [Information] Entity Framework Core "2.0.0-rtm-26452" initialized '"ApplicationDbContext"' using provider '"Npgsql.EntityFrameworkCore.PostgreSQL"' with options: "None"
2017-12-02 19:45:27.762 -05:00 [Debug] System.InvalidOperationException occurred, checking if Entity Framework recorded this exception as resulting from a failed database operation.
2017-12-02 19:45:27.762 -05:00 [Debug] Entity Framework did not record any exceptions due to failed database operations. This means the current exception is not a failed Entity Framework database operation, or the current exception occurred from a DbContext that was not obtained from request services.
2017-12-02 19:45:27.763 -05:00 [Error] An unhandled exception has occurred while executing the request
System.InvalidOperationException: An attempt was made to use the context while it is being configured. A DbContext instance cannot be used inside OnConfiguring since it is still being configured at this point. This can happen if a second operation is started on this context before a previous operation completed. Any instance members are not guaranteed to be thread safe.
at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
at Microsoft.EntityFrameworkCore.DbContext.Set[TEntity]()
at Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore`9.get_UsersSet()
at Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore`9.FindByIdAsync(String userId, CancellationToken cancellationToken)
at Microsoft.AspNetCore.Identity.UserManager`1.FindByIdAsync(String userId)
at MyProject.TokenProviderMiddleware.<GetUserAsync>d__9.MoveNext() in /home/jrow/Projects/MyProject/MyProject/Middleware/TokenProviderMiddleware.cs:line 220
System.ObjectDisposedException: Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose() on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'AsyncDisposer'.
at Microsoft.EntityFrameworkCore.Internal.ConcurrencyDetector.AsyncDisposer.Dispose()
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider.ExceptionInterceptor`1.EnumeratorExceptionInterceptor.<MoveNext>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
at System.Linq.AsyncEnumerable.<Aggregate_>d__6`3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore`9.<GetClaimsAsync>d__38.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Microsoft.AspNetCore.Identity.UserManager`1.<GetClaimsAsync>d__103.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at MyProject.TokenProviderMiddleware.<CreateClaims>d__10.MoveNext() in /home/jrow/Projects/MyProject/MyProject/Middleware/TokenProviderMiddleware.cs:line 239
答案 0 :(得分：1)
通过传递变量而不是每次全局新增来修复它。 （得到了reddit的回答）。
public async Task Invoke(HttpContext context, UserManager<ApplicationUser> userManager)
{
...
try
{
user = await GetUserAsync(_userManager, context, "from_refresh_token");
}
...
}
private async Task<ApplicationUser> GetUserAsync(UserManager<ApplicationUser> _userManager, HttpContext context, string getUserFrom)
{
//Do stuff with _userManager
}
答案 1 :(得分：0)
如果您的UserManager依赖于dbcontext，则它不应该是单例。应为每个请求单独创建dbcontext。使您的UserManager瞬态正确管理dbcontext。