AspectJ-编织jdk和非jdk类-NoClassDefFoundError

Question

I have three projects setup in eclipse,

1) aspects_project - this AspectJ project contains an aspect 'testaspect' I want to weave into certain JDK classes and also the classes within application_project

2) application_project - this project has aspects_project on its Aspect Path.

3) jdk_project - this project has aspects_project on its Aspect Path and classes.jar on its InPath. It is set to output classes_weaved.jar

When I run application_project with classes_weaved.jar preprended to the bootclasspath, the weaved advice in classes of application_project works fine but the advice weaved into the jdk classes gives me the runtime error:

Exception in thread "main" java.lang.NoClassDefFoundError: testaspect

So the advice weaved into jdk classes cannot find the aspect class that contains the advice.

Answer 1

Because the classes_weaved.jar is on the bootclasspath you also need to ensure the aspect is visible at that level of the class loader hierarchy. The aspect may be on the regular class path but due to class loader visibility rules those jdk classes cannot see it 'down below'. You can either ensure the testaspect is placed into the classes_weaved.jar or you can also add the output from the aspects_project to the bootclasspath.

To do the former (add it to the classes_weaved.jar) I think you could put aspects_project on the inpath (as well as the aspect path) of the jdk_project.