[英]Automapper/StructureMap issues with TPL version of synchronous code
[英]How to simplify or wrap exceptions when rewriting synchronous code to use TPL
鑒於實施如下:
public class SomeServiceWrapper
{
public string GetSomeString()
{
try
{
//Do Something
}
catch (IOException e)
{
throw new ServiceWrapperException("Some Context", e);
}
catch (WebException e)
{
throw new ServiceWrapperException("Some Context", e);
}
}
}
上述目的是使GetSomeString
的使用者只需要捕獲ServiceWrapperException
。
請考慮以下方法以使用類似的異步行為來擴展它:
public Task<string> GetSomeStringAsync()
{
Task<string>.Factory doSomething = ...
return doSomething.ContinueWith(x =>
{
if (x.IsFaulted)
{
if (x.Exception.InnerExceptions.Count() > 1)
{
throw new AggregateException(x.Exception);
}
var firstException = x.Exception.InnerExceptions[0];
if (typeof(firstException) == typeof(IOException)
|| typeof(firstException) == typeof(WebException))
{
throw new ServiceWrapperException("Some Context", firstException);
}
}
return x.Result;
}
}
這種包裝異常的同步方法自然不適合異步方法。
SomeServiceWrapper
的作者可以做些什么來簡化任何消費者的異常處理代碼,這樣他們只需要處理TradeLoaderException
而不是IOException
和WebException
?
我做了一個擴展方法,幾乎就是這樣。 用法:
public static Task<string> GetSomeStringAsync()
{
var doSomething = Task.Factory.StartNew(() => "bar");
return doSomething.WrapExceptions(typeof(IOException), typeof(WebException));
}
方法:
public static Task<TResult> WrapExceptions<TResult>(this Task<TResult> task, params Type[] exceptionTypes)
{
return task.ContinueWith(_ =>
{
if (_.Status == TaskStatus.RanToCompletion) return _.Result;
if (_.Exception.InnerExceptions.Count > 1)
{
throw new AggregateException(_.Exception);
}
var innerException = _.Exception.InnerExceptions[0];
if (exceptionTypes.Contains(innerException.GetType()))
{
throw new ServiceWrapperException("Some Context", innerException);
}
throw _.Exception;
});
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.