Unity Interception and Exceptions

Question

hi there,

i´m currently dealing with an issue where i have a lot of iterfaces and their implementations all created with unity. those classes contain some methods that throw exceptions on a regular base and i wanted to create a dynamic proxy around those classes so i can catch all exceptions occured in methods do handle them somewhere else.

As i´m playing with Unity, i wonder if something like this can be done using Unity Interception.

i.e. create a TransparentProxyInterceptor and wrap a try-catch block around the invocatino of these methods. is this possible at all or am i going into the wrong direction? thanks

Answer 1

Yes, Unity interception (AOP) is an excellent way to deal with exception handling. You can add all kinds of behavior like:

• write to a log file or the event log
• send an email
• increment a performance counter
• auto retry on timeout or lock exception
• rethrow a different error

Your call handler will look something like:

public override IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)
{
    IMethodReturn result = getNext()(input, getNext);

    if (result.Exception != null)
    {
        // do something
    }

    return result;
}