我目前正在重構一個使用邏輯流異常的應用程序。該代碼很難閱讀和維護,並使得像我這樣的S.O.L.I.D迷迷們在閱讀時哭泣(更不用提我在職業生涯中見過的最長的catch block)。工作流的重構例外
我的問題是你可以使用什麼樣的模式來使它更容易維護或你將如何去重構?
public void CallExternalServices(ICriteria criteria)
{
try
{
someResult = ExternalService1.SomeMethod(criteria);
}
catch (Service1Exception service1Exception)
{
if (criteria.SomeValue == "1")
{
if (service1Exception.InnerException != null
&& service1Exception.InnerException.InnerException != null
&& service1Exception.InnerException.InnerException is TargetSystemException)
{
TargetSystemException targetSystemException = (TargetSystemException)service1Exception.InnerException.InnerException;
if (targetSystemException.ErrorStatus.IsServiceDownForMaintenance())
{
// Call internal method to perform some action
SendNotification("Service down for maintenance.")
}
}
}
else if (criteria.SomeValue == "2")
{
if (service1Exception.InnerException != null
&& service1Exception.InnerException.InnerException != null
&& service1Exception.InnerException.InnerException is TargetSystemException)
{
TargetSystemException tx = (TargetSystemException)service1Exception.InnerException.InnerException;
if (targetSystemException.ErrorStatus.IsBusy())
{
// Call to some internal method to perform an action
SendDifferentNotification()
criteria.SetSomeFlagToBe = true;
try
{
someResult = ExternalService2.SomeOtherMethod(criteria);
}
catch (Service2Exception service2Exception)
{
if (service2Exception.InnerException != null
&& service2Exception.InnerException.InnerException != null
&& service2Exception.InnerException.InnerException is TargetSystemException)
{
TargetSystemException tx = (TargetSystemException)service1Exception.InnerException.InnerException;
if (targetSystemException.ErrorStatus.HasNumberOfDailyTransactionsBeenExceeded())
{
// Call internal method to perform some action
SendNotification("Number of daily transactions exceeded.")
}
}
else if (service2Exception.InnerException != null
&& service2Exception.InnerException.InnerException != null
&& service2Exception.InnerException.InnerException is FaultException)
{
FaultException faultException = service2Exception.InnerException.InnerException as FaultException;
if (faultException.Detail != null
&& faultException.Detail.FaultMessage.Equals("SomeValueToCheckAgainst", StringComparison.OrdinalIgnoreCase))
{
return someResult;
}
else
{
throw service2Exception;
}
}
else
{
throw service2Exception;
}
}
if (someResult != null)
{
// perform another action
SomeActionInvoker.ExecuteAcitonAgainst(someResult);
}
}
}
else if (service1Exception.InnerException != null
&& service1Exception.InnerException.InnerException != null
&& service1Exception.InnerException.InnerException is FaultException)
{
FaultException faultException = service1Exception.InnerException.InnerException as FaultException;
if (faultException.Detail != null
&& faultException.Detail.FaultMessage.Equals("SomeOtherValueToCheckAgainst", StringComparison.OrdinalIgnoreCase))
{
return someResult;
}
else
{
throw service1Exception;
}
}
else
{
throw service1Exception;
}
}
}
}