Hi guys,
I'm currently spending some time documenting the AbstractIoService
class, where the ExceptionMonitor instance is created. This class is
just used to handle exception when they are uncaught :
/**
* Monitors uncaught exceptions. [EMAIL PROTECTED] #exceptionCaught(Throwable)}
is
* invoked when there are any uncaught exceptions.
*/
public abstract class ExceptionMonitor {
...
At least, this is what the Javadoc says ... But in fact, 'uncaught
exception' does not make a lot of sense. Either we catch an exception,
or not. If we don't catch it, there is no way to deal with it as an
uncaught exception, because otherwise, it means it has been caught, and
is not anymore uncaught ... :/
There is soemthing wrong in this logic. All over the code, we see things
like :
try {
...
} catch (Throwable t) {
ExceptionMonitor.getInstance().exceptionCaught(t);
}
Assuming that we are using the DefaultExceptionMonitor, this will simply
log a warning in some log :
public class DefaultExceptionMonitor extends ExceptionMonitor {
private final Logger log =
LoggerFactory.getLogger(DefaultExceptionMonitor.class);
public void exceptionCaught(Throwable cause) {
if (log.isWarnEnabled()) {
log.warn("Unexpected exception.", cause);
}
}
Why don't we simply write :
try {
...
} catch (Throwable t) {
log.warn("Unexpected exception.", t);
}
?
Now, the question is why do we allow a user to define it's own
ExceptionMonitor to handle unhandled exceptions. As we are defining a
framework, it does not make a lot of sense to disregard an exception and
let the user define what to do with it, as the user will have _no clue_
about where those kind of exception might be produced (our users are not
all supposed to go through MINA code).
So do we really need this class ? IMHO, this is a bad idea which has not
been removed from the very first version (it comes far away : the class
has been injected back in 2005, and was never derived since, if we
except the default implementation.
wdyt ?
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org
