JsonValueProviderFactory: System.ArgumentException:已经添加了一个具有相同键的项

Question

我有一个用于Shopify的web钩子api处理程序，它用一个json主体调用下面的控制器操作。它立即失败，因为没有到达并记录任何log4net日志记录，只有OnException方法中的日志记录错误如下。

问题1:

Elmah日志中的Stack跟踪没有帮助，因为它不足以显示代码中的哪一行引发了错误。为什么会这样呢？我注意到async errors...they似乎很难确定代码中的根本原因行。也许我现在应该把它变成一个同步的方法？也许我应该摆脱OnException方法，因为它可能掩盖了更多的信息？

问题2:

在执行任何代码之前，一旦执行控制器操作，什么可能会导致这个错误？该控制器继承了asp.net mvc Controller，构造函数中唯一的代码是创建DBContext和log4net _logger的实例。

堆栈跟踪：

Controllers.ShopWebhooksController.OnException(C:\inetpub\wwwroot\Controllers\ShopWebhooksController.cs:44)
System.ArgumentException: An item with the same key has already been added.
       at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
       at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.AddToBackingStore(EntryLimitedDictionary backingStore, String prefix, Object value)
       at System.Web.Mvc.JsonValueProviderFactory.GetValueProvider(ControllerContext controllerContext)
       at System.Web.Mvc.ValueProviderFactoryCollection.GetValueProvider(ControllerContext controllerContext)
       at System.Web.Mvc.ControllerBase.get_ValueProvider()
       at System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor)
       at System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor)
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass3_1.<BeginInvokeAction>b__0(AsyncCallback asyncCallback, Object asyncState)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout)
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state)
       at System.Web.Mvc.Controller.<>c.<BeginExecuteCore>b__152_0(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout)
       at System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout)
       at System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state)
       at System.Web.Mvc.MvcHandler.<>c.<BeginProcessRequest>b__20_0(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout)
       at System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state)
       at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
       at System.Web.HttpApplication.<>c__DisplayClass285_0.<ExecuteStepImpl>b__0()
       at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
       at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

下面是控制器，OrderUpdate是被调用的操作：

public class ShopWebhooksController : Controller
{
private readonly ILog _logger;
private readonly InventoryMgmtContext _dbContext;

public ShopWebhooksController()
{
    _logger = LogManager.GetLogger(GetType());
    _dbContext = new InventoryMgmtContext();
}

protected override void OnException(ExceptionContext filterContext)
{
    Exception ex = filterContext.Exception;
    var action = filterContext.RouteData.Values["action"];
    // TODO: Log or report your exception.
    string msg = $"Exception in shopify webhook controller action: {action}. Message: {ex.Message}. Stack: {ex.StackTrace}.";
    _logger.Error(msg); **<---- this is being logged**

    filterContext.Result = new HttpStatusCodeResult(HttpStatusCode.OK, msg);

    //Let the base controller finish this execution
    base.OnException(filterContext);
}      


[HttpPost]
public async Task<ActionResult> OrderUpdated (int storefrontId)
{
    string msg = "Successfully submitted update request to Mozzo.";
    string webhook = "orders/updated";
    _logger.Debug($"Shopify {webhook} request received."); **<-- not being logged**

    try
    {
        var validationResult = await ValidateStorefrontWebhook(webhook, storefrontId);
        if (!validationResult.WasSuccessful) return new HttpStatusCodeResult(HttpStatusCode.OK, validationResult.Message);

        var orderSyncAppServ = new SyncErpWithPlacedOrdersTask();
        Hangfire.BackgroundJob.Enqueue(() => orderSyncAppServ.UpdateOrderFromWebhook(validationResult.Value, storefrontId));
    }
    catch (Exception e)
    {
        msg = $"Exception webhook: {webhook} for storefront Id: {storefrontId}. {e.Message}.";
        _logger.Error(msg);
    }
    return new HttpStatusCodeResult(HttpStatusCode.OK, msg);
}

#endregion

#region Private Methods


/// <summary>
/// Validates the webhook is authentic and returns the body of the request as a string
/// </summary>
/// <param name="webhook"></param>
/// <param name="storefrontId"></param>
/// <returns>request body (string version of an order, etc.</returns>
private async Task<ActionConfirmation<string>> ValidateStorefrontWebhook(string webhook, int storefrontId)
{
    string returnMessage = "";     

    //log request
    //get the request body (a json string of an order, product, etc coming from shopify.
    string jsonObject = await GetRequestBody();

    //wrap in brackets to make it an array of one because our import takes an array or orders
    jsonObject = $"[ {jsonObject} ]";

    //get storefront
    var storefront = await _dbContext.StoreFronts.Where(s => s.Id == storefrontId).SingleOrDefaultAsync();
    if (storefront == null) {
        returnMessage = $"Shopify {webhook} webhook request for Storefront Id: {storefront.Id} - storefront not found!";
        _logger.Error($"{LogHelper.GetCurrentMethodName()}: {returnMessage}");
        return ActionConfirmation<string>.CreateFailureConfirmation(returnMessage, "", false);
    }

    log4net.LogicalThreadContext.Properties["AccountId"] = storefront.Company.AccountId;
    log4net.LogicalThreadContext.Properties["CompanyId"] = storefront.CompanyId;
    log4net.LogicalThreadContext.Properties["FacilityId"] = null;
    log4net.LogicalThreadContext.Properties["UserId"] = null;

    string shopDomain = storefront.APIUrl;
    string shopSecretKey = storefront.StoreFrontTypeId == (int)StoreFront.StoreFrontTypes.ShopifyPrivate
        ? storefront.AccessToken
        : AppSettings.ShopifySecretKey;

    _logger.Debug("About to check if webhook is authentic");

    var isValidRequest = await AuthorizationService.IsAuthenticWebhook(
        Request.Headers.ToKvps(),
        Request.InputStream,
        shopSecretKey);

    if (!isValidRequest)
    {
        returnMessage = $"Shopify {webhook} webhook request for Storefront Id: {storefront.Id} is not authentic!";
        _logger.Error($"{LogHelper.GetCurrentMethodName()}: {returnMessage}"); 
        return ActionConfirmation<string>.CreateFailureConfirmation(returnMessage, "", false);
    }

    returnMessage = $"Shopify {webhook} webhook request for Storefront Id: {storefront.Id} is authentic!";
    _logger.Info($"{LogHelper.GetCurrentMethodName()}: {returnMessage}");            

    return ActionConfirmation<string>.CreateSuccessConfirmation(returnMessage, jsonObject, false);
}

private async Task<string> GetRequestBody()
{
    _logger.Debug($"{LogHelper.GetCurrentMethodName()}: Attempting to get request body.");

    //ShopifySharp has just read the input stream. We must always reset the inputstream
    //before reading it again.
    Request.InputStream.Position = 0;

    //Do not dispose the StreamReader or input stream. The controller will do that itself.
    string bodyText = await new StreamReader(Request.InputStream).ReadToEndAsync();

    _logger.Debug($"{LogHelper.GetCurrentMethodName()}: Request body: {bodyText}.");

    return bodyText;
}
#endregion  

更新-问题和解决方案

问题确实是，Shopify Order webhook JSON对象包含重复的键，因为它们在同一个对象包装器中有一个lowercase和TitleCase版本的4个键。

​

这些密钥的完整路径是：

order,refunds,0,transactions,0,receipt,version
order,refunds,0,transactions,0,receipt,timestamp
order,refunds,0,transactions,0,receipt,ack
order,refunds,0,transactions,0,receipt,build

我所做的确切的代码修改如下。在添加自己的JsonValueProviderFactory类时，我确实遵循了下面提供的答案，但没有提供的是对make...because的确切更改--这取决于您想要如何处理它。在我的示例中，此更改将导致抛出同名的任何后续键。因此，如果您想要以不同的方式处理它，您需要按您的意愿来处理：

/// <summary>
/// Modified this to handle duplicate keys
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
public void Add(string key, object value)
{
    if (++_itemCount > _maximumDepth)
    {
        throw new InvalidOperationException("The JSON request was too large to be deserialized.");
    }

    // Add the following if block so if the key already exists, just return instead of trying to add it to the dictionary which will throw an error.
    if (_innerDictionary.ContainsKey(key))
    {
        return;
    }

    _innerDictionary.Add(key, value);
}

Answer 1

我认为您的设计没有什么问题，但是您的一个类可能有重复的属性，这会导致运行时异常。

例如

public int storefrontId {get; set;}
public int StorefrontId {get; set;}

您需要配置log4net来记录您的操作调用。前任：

2021-02-16 10:24:17.5632|2|INFO|Microsoft.AspNetCore.Hosting.Diagnostics|Request finished in 141.7419ms 200  |url: http://myapp/OrderUpdated|action:

这里是如何使用DelegatingHandler进行请求日志的编辑

public class RequestLogHandler : DelegatingHandler
{
    private static readonly ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
    
    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        if (request.Content != null)
        {
            string requestBody = await request.Content.ReadAsStringAsync();
            log.Info($"url {request.RequestUri} body = {requestBody}");
        }
        //// let other handlers process the request
        var result = await base.SendAsync(request, cancellationToken);

        return result;
    }
}

配置中的寄存器处理程序

config.MessageHandlers.Add(new RequestLogHandler());

这会给你以下的东西。

​

此外，我将告诉您重写JsonValueProviderFactory AddToBackingStore方法的步骤。您可以使用它来查找导致此问题的属性。

1. 从这里获取源代码。
2. 添加类MyJsonValueProviderFactory.cs
3. 在JsonValueProviderFactoruy之前在Global.asax.cs中注册新类 ValueProviderFactories.Factories.Insert(0，新MyJsonValueProviderFactory())；

或者先删除原版，然后使用你的。

ValueProviderFactories.Factories.Remove(ValueProviderFactories.Factories.OfType<JsonValueProviderFactory>().FirstOrDefault());
ValueProviderFactories.Factories.Add(new MyJsonValueProviderFactory());

使用这个类进行异常捕获，您将能够找到问题所在，您可以从EntryLimitedDictionary类中的Add方法开始。

再次使用下面的链接注册错误处理全局。https://learn.microsoft.com/en-us/aspnet/web-api/overview/error-handling/exception-handling

Answer 2

我不确定我是否理解您是否正确，但是尝试使用带有日志记录的附加方法临时包装后台调用，然后尝试catch：

BackgroundJob.Enqueue(() => UpdateOrderFromWebhookWithLogging(_logger, validationResult.Value, storefrontId));

并将此方法添加到控制器中：

// I don't know types to write correct signature
private void UpdateOrderFromWebhookWithLogging(_logger, orderSyncAppServ, validationResult.Value, storefrontId)
        {
            try
            {
                orderSyncAppServ.UpdateOrderFromWebhook(validationResult.Value, storefrontId)
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                throw;
            }
        }

Answer 3

看起来，JsonValueProviderFactory.AddToBackingStore正在遍历JSON输入并将每个叶值放入字典中。字典的关键是叶节点的路径。如果遍历遇到两个具有相同路径的叶节点，则会发生此异常。

我认为您需要检查JSON输入数据--也许它有重复的键。例如，这是有效的JSON：

{
    "id": 1,
    "name": "Some Name"
}

而这并不是：

{
    "id": 1,
    "name": "Some Name",
    "id": 2
}

因为"id“键出现不止一次。这可能会导致你看到的错误。