Question

I’ve read some articles of aspectj, I know it can enhance classes, which is attractive. I’ve a very stupid question that I can’t find a clear answer:

Can aspectj add methods to java.lang.String?

Or similar question: If I can’t get the sources of some classes, can I enhance them by aspectj?

Answer 1

No, you can’t do this my friend.

I think this is what you are looking for Type not exposed to user

For further details please take a look at The AspectJ Development Environment Guide #Special Cases

As it says

The following classes are not exposed to the LTW infrastructure regardless of the aop.xml file(s) used

• All org.aspectj.* classes (and subpackages) – as those are needed by the infrastructure itself
• All java.* and javax.* classes (and subpackages)
• All sun.reflect.* classes – as those are JDK specific classes used when reflective calls occurs