Throwing and logging Exceptions, a better way

Question

Ultimately, i'd like to

if (badThingsHappen) {
 log the issue
 throw exception with description
}

The obvious redundancy here is that often exception description and the message to be logged is (often) the same.

This looks needlessly verbose

if (badThingsHappen) {
 logger.error("oh no! not again!");
 throw new AppException("oh no! not again!");
}

Declaring temporary String feels wrong

if (badThingsHappen) {
 String m = "oh no! not again!";
 logger.error(m);
 throw new AppException(m);
}

Is it ok to have Exception's constructor handle the logging? Is there a better (cleaner) way?

Answer 1

You could use a utility method:

public class AppException extends Exception {
    public static AppException logAndThrow(Logger logger, String message) throws AppException {
        AppException e = new AppException(message);
        // log the stack trace as well
        logger.error(message, e);
        throw e;
    }
}

and the use it:

if (badThingsHappen) {
    AppException.logAndThrow(logger, "oh no! not again!");
}