Question

I have a generic question regarding to how to design error handling. I want to use some third-party service in my code. Normally I wrap the service within a client class. Then the rest of my code only deals with my client class and is blind to the real service under the hook. My client class has some mechanism to log errors. But it doesn’t want to catch and deal any exception from the service. Ideally it should just ignore the exception handling and let the exception propagates to outside. However, if I want to log the exception, I have to do something like this:

try{
    .... // call 3rd party service;
}catch(Exception e){ // e is triggered from the service;
    Log.error("Oops, an error: " + e); // shall I log the exception??
    throw e; // don't swallow the exception;
}

On one hand, I don’t want to do this. I can ignore the handling and logging of the exception. Let the caller of my client class handles exceptions or logs errors. The question is, when should I log exceptions and when should I not? I’d like to hear some common practice and principles. Thank you.

Answer 1

Don’t log the exception at every level. Log it only at the “top” level. Log it at the point where not logging it would cause the exception to be missed.