[jetty-dev] WebAppClassLoader dependency on java.lang.instrument

[Eirik Bjørsnøs <eirbjo@xxxxxxxxx>]

Hi,

WebAppClassLoader currently uses java.lang.ClassFileTransformer as the API for doing class file transformations during class loading.

While this is not wrong per the API specification, it does incur a dependency on the "somewhat optional" java.transformation module. This module is not included in the default java boot layer, so might need extra configuration/command line switches to enable. It's also an additional dependency which needs to be included in jlink runtime images, etc.

While I understand it is convenient to reuse an existing interface that's already in the JDK, I was wondering if it would make sense for Jetty to have its own interface for this purpose. Existing implementations could easily be plugged in via delegating wrappers.

I understand that this could have compatibility issues, so not really expecting this dependency to be dropped soon. But I wanted to share the observation anyhow.

Cheers,

Eirik.