Prior to this change the checks for isVariableName were duplicated in 2 different locations. The logic has been moved to a utility class to allow for re-use in those places and so that it benefits from any optimizations that are done.

Comment From: jhoeller

Rather than introduce a new utility class, couldn't we add that isVariableName method to the existing AspectJProxyUtils? Since both of the callers live in the same package, we could even declare it as package-visible there.

Comment From: sbrannen

In light of @jhoeller's simultaneous review (https://github.com/spring-projects/spring-framework/pull/26107#issuecomment-728952313), you may ignore my review in favor of his suggestions.

Comment From: mdeinum

Rather than introduce a new utility class, couldn't we add that isVariableName method to the existing AspectJProxyUtils? Since both of the callers live in the same package, we could even declare it as package-visible there.

Adding it in that place was my first thought, didn't consider making it package visible. Will move it there and force push.