I managed to bring IBM jdk support to AspectWerkz for on the fly weaving.
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IBM bundles a specific JRE that I did not planned when hacking the JVM hook architecture that allow on the fly weaving, so some of you reported JVM crash. Now it is fixed (in CVS HEAD) and for other exotic VM, an explicit error message should be reported.

If you have issues with it, please provide feedback. The IBM jre (at least 1.3.x) seems to have many issues as regards jars packaging. f.e I had to remove index.lst from meta-inf/ in two third parties jars for it to work...

Using the latest development of AspectWerkz, and thus the recently released 0.8.1, debugging step by step your aspects is made easy.

Indeed we now have support for standard IDE debugging, so that bytecode weaving process can be followed step by step as regular java.

Then when your weaved application is running, you can set breakpoints on your advices and debug the app as usual, as plain java, as you are probably used to do it.
Though the IDE does not have access to the source of the weaved classes, you can set breakpoints in the original method affected by the pointcuts where aspects are bounded.

Here are some screenshot with IntelliJ.