Hi Tobias,
You can use annotations at the method
level to address this: you could then look at thisEnclosingJoinPointStaticPart
to see if there is an appropriate annotation. If you find that the same
exception is handled differently in the same method, I’d suggest
extracting a method to deal with this. This would be a lot cleaner than using a
naming convention on the methods.
As you noted, it isn’t possible to
use variable annotations both because they are not retained in the binary
representation and AspectJ relies on binary representations for weaving. Also AspectJ
doesn’t in general expose information about local variables (e.g., there
is way to match pointcuts or expose join point information based on local
variables). By the same token, you can’t determine the name of the local variable
being used in the catch block, so a naming convention like this wouldn’t
help with AspectJ. This is a good thing IMHO: it would be too brittle if
renaming local variables would change pointcut matching…
From: aspectj-users-bounces@xxxxxxxxxxx
[mailto:aspectj-users-bounces@xxxxxxxxxxx] On
Behalf Of Tobias Dunn-Krahn
Sent: Wednesday, November 30, 2005
2:03 PM
To: gregor@xxxxxxxxx;
aspectj-users@xxxxxxxxxxx
Subject: RE: [aspectj-users]
Excluding Particular Joinpoints
Gregor and Ron,
Thanks for your suggestions.
Unfortunately in my case, I can’t determine from just the Throwable
whether or not it should be logged. For example, a FooBarException should
be logged in some cases but not others, depending on the surrounding
application logic. Really the only way to determine this is a decision on
the part of developer, which is why I was experimenting with annotations.
Perhaps I could use thisJoinPoint in combination
with a naming convention for the throwable, i.e. any throwable named
“expectedThrowable” would not be logged. It would be nice if
I could do something more explicit (like an annotation) but perhaps it’s
not possible. Please let me know if I’ve misunderstood something
about your suggestions.
Thanks,
Tobias
From:
aspectj-users-bounces@xxxxxxxxxxx [mailto:aspectj-users-bounces@xxxxxxxxxxx] On Behalf Of Gregor Kiczales
Sent: Wednesday, November 30, 2005
1:26 PM
To: aspectj-users@xxxxxxxxxxx
Subject: RE: [aspectj-users]
Excluding Particular Joinpoints
From: aspectj-users-bounces@xxxxxxxxxxx
[mailto:aspectj-users-bounces@xxxxxxxxxxx] On
Behalf Of Tobias Dunn-Krahn
I am using AspectJ in a project to log
all handled exceptions. In general this is what I want, but in a small
number of cases such exceptions are “expected” and I do not wish to
log them.
aspect
FooBarExceptionLoggingStrategy {
before(Throwable t): handler(Throwable) && args(t) {
if( shouldLog(t) )
log(t);
}
private
boolean shouldLog(Throwable t) {
<<test whatever needs testing here>>
}
private
void log(Throwable t) {
...
}
}
The point being that you can test the
exception in any way you want before logging it.
You could also pass thisJoinPoint or
thisJoinPointStaticPart. If you want, you could
move shouldLog into the actual pointcut,
using if(shouldLog(t)).
From:
aspectj-users-bounces@xxxxxxxxxxx [mailto:aspectj-users-bounces@xxxxxxxxxxx] On Behalf Of Tobias Dunn-Krahn
Sent: Wednesday, November 30, 2005
11:42 AM
To: aspectj-users@xxxxxxxxxxx
Subject: [aspectj-users] Excluding
Particular Joinpoints
Hello All,
I am using AspectJ in a project to log all handled
exceptions. In general this is what I want, but in a small number of
cases such exceptions are “expected” and I do not wish to log
them. My pointcut definition is currently very simple; it matches all
exception handlers except those that handle SocketTimeoutExceptions:
pointcut exceptionHandlers(Throwable t) :
handler(Throwable+) && (args(t)
&&
!args(java.net.SocketTimeoutException));
However, now I need to exclude matching of particular
exception handlers that are not distinguishable by type. I tried creating
a custom annotation with target type LOCAL_VARIABLE and using this annotation
to decorate the exception, but unfortunately annotations of this type are not
retained for runtime (and are therefore inaccessible). Does anyone have
any suggestions?
Thanks in advance,
Tobias
