Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
398 views
in Technique[技术] by (71.8m points)

c# - How can I improve this exception retry scenario?

I have a web service method I am calling which is 3rd party and outside of my domain. For some reason every now and again the web service fails with a gateway timeout. Its intermittent and a call to it directly after a failed attempt can succeed.

Now I am left with a coding dilemma, I have code that should do the trick, but the code looks like amateur hour, as you'll see below.

Is this really bad code, or acceptable given the usage? If its not acceptable, how can I improve it?

Please try hard to keep a straight face while looking at it.

try
{
    MDO = OperationsWebService.MessageDownload(MI);
}
catch
{
    try
    {
        MDO = OperationsWebService.MessageDownload(MI);
    }
    catch
    {
        try
        {
            MDO = OperationsWebService.MessageDownload(MI);
        }
        catch
        {
            try
            {
                MDO = OperationsWebService.MessageDownload(MI);
            }
            catch 
            {
                try
                {
                    MDO = OperationsWebService.MessageDownload(MI);
                }
                catch (Exception ex)
                {
                    // 5 retries, ok now log and deal with the error.
                }
            }
        }
    }
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

You can do it in a loop.

Exception firstEx = null;
for(int i=0; i<5; i++) 
{
    try
    {
        MDO = OperationsWebService.MessageDownload(MI);
        firstEx = null;
        break; 
    }
    catch(Exception ex)
    {
        if (firstEx == null) 
        {
            firstEx = ex;
        }
        Thread.Sleep(100 * (i + 1));
    }
}
if (firstEx != null) 
{
    throw new Exception("WebService call failed after 5 retries.", firstEx);
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...