Summary

Consistently throw GenericSignatureFormatError for invalid descriptor strings and TypeNotPresentException for a missing class or interface in the parsing workload used by Class::getEnclosing... methods and AnnotatedElement retrievals of annotation instances.

Problem

The previous migration of method and field descriptor parsing from generic signature parser to descriptor parser in java.lang.invoke had a few significant issues:

1. It did not have proper filter for . presence in descriptor strings. So strings like Ljava.lang.Object; were erroneously accepted.
2. Invalid descriptors like L; or L/Missing; would result in TypeNotPresentException instead of GenericSignatureFormatError as before.
3. Using field type in the NameAndType for EnclosingMethod attribute would result in a spurious IllegalArgumentException in method descriptor parsing. This was previously GenericSignatureFormatError.

This deviates from our goal for throwing GenericSignatureFormatError for all invalid descriptor strings, and throwing TypeNotPresentException for all missing classes or interfaces.

Solution

Correct these mistakes before they accidentally become program dependencies in the next feature release.

Specification

None. This is a purely implementation/behavioral change.

The affects APIs getEnclosing... and AnnotatedElement have other kinds of exceptions arising from other failures other than descriptor string parsing. These behaviors are not affected.