Well, yes you will have to use new syntax--as my example illustrated. And yes, AOP is a relatively new paradigm, with the associated wrinkles and complexity. However, much like OO, it has the potential to revolutionize the way we program. For instance, instead of using System.err, I could use Log4j and apply my exception handling changes to the whole codebase in 3 minutes...
I just wanted to bring it up so that people could start thinking about its potential application to Struts. Cheers, Nick -----Original Message----- From: John Yu [mailto:[EMAIL PROTECTED]] Sent: Friday, January 11, 2002 3:13 AM To: Struts Developers List Subject: Re: AspectJ and Struts Exception handling: I did some research on aspect-oriented programming (AOP) about a year ago. It is a relatively new paradigm. The current stage of AOP is like the stage of OOP twenty years ago: AOP introduces new syntax. To use it you need a pre-processor (that's what AspectJ does). (As an analogy, twenty years ago, C++ introduced new syntax to C. To use C++, you needed C-front to pre-process C++ into C.) I personally find AOP intriguing. However, as with any cutting-edge technologies, we need to treat it with caution. As far as I can see, the major implication is that developers will no longer write code in Java; we will write code in "Java++"--Java with AOP syntax. :) -- John At 03:51 pm 10-01-2002 -0700, you wrote: >Hello, > >A while back Rick Hightower submitted a request to change the way Struts >handles errors. His problem (and mine) is that Struts tends to catch >exceptions and throw different exceptions indicating the problem. Needless >to say this can badly obscure the original cause of the error. > >So today I set about remedying it using AspectJ--an aspect oriented >extension to Java produced by Xerox PARC (http://www.aspectj.org). I added >the following aspect to the org.apache.struts package: > >public aspect ExceptionLogger+AHs- > > before(Throwable e) : args(e) +ACYAJg- handler(Throwable+-)+AHs- > System.err.println(+ACI-Exception caught in the Struts > framework:+ACI-)+ADs- > e.printStackTrace(System.err)+ADs- > +AH0- >+AH0- > >Then I compiled Struts with an Ant task for AspectJ compilation: > >+ADw-target name+AD0AIg-compile.library+ACI- >depends+AD0AIg-prepare.library+ACI- > description+AD0AIg-Compile Struts library files+ACIAPg- > +ADw-ajc srcdir+AD0AIgAkAHs-src.share.dir+AH0AIg- > destdir+AD0AIgAkAHs-build.home+AH0-/library/classes+ACIAPg- > +ADw-classpath refid+AD0AIg-compile.classpath+ACI-/+AD4- > +ADw-/ajc+AD4- > +AFs-...task continues as normal...+AF0- > >Now all exceptions caught in the Struts framework are automatically logged >to System.err. > >So my question is: > >Should we consider the use of AspectJ in Struts? This would potentially >have no effect on the users of the framework, but could be valuable for >implementing logging and error-handling policies. The above code could be >modified to write to a log4j log if that would be more convenient. > >Does this intrigue anyone? Should we continue investigation? > >Cheers, > >Nicholas Lesiecki > >(For more info on AspectJ, look for my forthcoming article on IBM's >developerWorks.) > >Technical Team Lead >eBlox, Inc. >(520) 615-9345 x104 >Check out my new book+ACE-: >Java Tools for Extreme Programming: Mastering Open Source Tools, including >Ant, JUnit, and Cactus > >http://www.amazon.com/exec/obidos/ASIN/047120708X/ > > > > >-- >To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> >For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- John Yu Scioworks Technologies e: [EMAIL PROTECTED] w: +(65) 873 5989 w: http://www.scioworks.com m: +(65) 9782 9610 Scioworks Camino - "Rapid WebApp Assembly for Struts" -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
