8009645: ClassFileTransformer hooks in ClassLoader no longer required

Mandy Chung mandy.chung at oracle.com
Fri Mar 8 16:53:11 UTC 2013

On 3/8/2013 8:27 AM, Alan Bateman wrote:
> I need a reviewer for a change to remove some crud from 
> java.lang.ClassLoader. The crud in question is a hook to allow 
> implementations of sun.misc.ClassFileTransformer be notified when 
> defineClass fails with a class format error. It was originally added 
> >10 years ago for Sun's Browser Plug-in to allow it fix up bad 
> JDK1.1-era class files. I have confirmed that this is no longer needed.
> As always with sun.misc classes it is useful to know if they are used 
> outside of the JDK. To than end, I checked the data that Mandy 
> collected on sun.* usage by artifacts in Maven Central.  In the case 
> of ClassFileTransformer, we only found one usage and that was in an 
> old version of an artifact so it's no longer an issue. Given that 
> java.lang.instrument has been available since JDK5 then there really 
> isn't any excuse to be using this class anyway.
> The webrev with the proposed changes is here. I've left 
> sun.misc.ClassFileTransformer in place for now with a warning in the 
> javadoc. It is a definitely a candidate to remove in the future.
> http://cr.openjdk.java.net/~alanb/8009645/webrev/

It's good to see this ancient hack go away.  Thumbs up.


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