I tried to search for the issue, also googlized it, but without any success.
In JBoss AOP 1.3 standalone :
Compile the "field-execution" example in the jboss 1.3 directory. It runs smoothly. Now rename field "var2" to "_var2" and run it again. I get
Exception in thread "main" java.lang.IllegalArgumentException at sun.reflect.UnsafeStaticIntegerFieldAccessorImpl.set(Unknown Source) at java.lang.reflect.Field.set(Unknown Source) at org.jboss.aop.joinpoint.FieldWriteInvocation.invokeNext(FieldWriteInvocation.java:60) at trace.TraceInterceptor.invoke(TraceInterceptor.java:173) ...
Subjet got truncated, it is supposed to end with "by underscore".