ClassFileTransformer does not apply to anonymous classes

Andrew Dinn adinn at
Thu Jan 21 09:07:41 UTC 2016

Hi Rafael,

On 01/12/15 12:45, Rafael Winterhalter wrote:
> I can tell that this behavior has not only affected me as I had this
> question comming up by multiple users of my open-source code generation
> library.
> What is your view on this?
> Thank you for your feedback!

I have an interest in this issue because I lead a Java agent-based
project (Byteman). I have not (yet) come across a case where the
behaviour you describe has affected the operation of my agent -- I
suspect that is because it will never attempt to transform a class
defined via Unsafe::defineAnonymousClass. However, I agree with you that
this behaviour appears anomalous and the outcome you describe is
counter-intuitive. I would be very interested to know if there was a
good reason for excluding anonymous classes from transformation.


Andrew Dinn
Senior Principal Software Engineer
Red Hat UK Ltd
Registered in UK and Wales under Company Registration No. 3798903
Directors: Michael Cunningham (US), Michael O'Neill (Ireland), Paul
Argiry (US)

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