Short Answer Don’t iterate through all the loaded classes from Instrumentation. Instead, just examine the class name passed in to the transformer and if it matches your target class, then transform it. Otherwise, simply return the passed classfileBuffer unmodified. Make the set up calls outside the transformer, (i.e. in your case, do the following from … Read more
Regular Spring @Components For an explanation of how normal Spring (AOP) proxies or dynamic proxies (JDK, CGLIB) in general work, see my other answer with illustrative sample code. Read that first and you will understand why self-invocation cannot be intercepted for these types of proxies via Spring AOP. @Configuration classes As for @Configuration classes, they … Read more
Since JDK 16, the default for the –illegal-access option is deny, so “deep reflection” to JDK classes fails. You can override the behavior by specifying –illegal-access=permit, but you have to be aware of JEP 403: Strongly Encapsulate JDK Internals which is about closing that possibility in a future version, so this option is only a temporary … Read more
Yes, Spring does some magic. Check the Spring Docs: This is where the magic comes in: All @Configuration classes are subclassed at startup-time with CGLIB. In the subclass, the child method checks the container first for any cached (scoped) beans before it calls the parent method and creates a new instance. This means that the … Read more
JDK Dynamic proxy can only proxy by interface (so your target class needs to implement an interface, which is then also implemented by the proxy class). CGLIB (and javassist) can create a proxy by subclassing. In this scenario the proxy becomes a subclass of the target class. No need for interfaces. So Java Dynamic proxies … Read more