Add Exception Type Parsing

[Pandrex247]

Ports an old addition we've had in our Payara patched-src fork for a while.

Exception types are now parsed from MethodModels.
This is used within Payara to help with MicroProfile OpenAPI support.

[pzygielo]

Shouldn't exceptionTypes be updated somewhere, perhaps here? Otherwise - how it gets populated?

Edit: I've removed locally this method and collection+getter and the test is fine with such change. Do we need exceptionTypes in this class?

[avpinchuk]

I agree with @pzygielo. This code doesn't do anything right now.

[Pandrex247]

I will review - I was simply cherry-picking from our fork (I didn't make the original change)

[Pandrex247]

This is an inherited method from the SignatureVisitor class from ASM: SignatureVisitor#L153.

There is an identical implementation of it over in the SignatureVisitorImpl class here in HK2: SignatureVisitorImpl#L88.

So I assume the original intent was to simply mirror the behaviour of the SignatureVisitorImpl class.

[pzygielo]

Could be to follow established pattern, right.
What would be the role of exceptionTypes?

[Pandrex247]

Would need to spend some time digging into it with a debugger - it's a bit abstract for my eyes to dry-run through.

The interface method from MethodModel (and presumably MethodModelImpl) gets used over in Payara for MicroProfile OpenAPI processing here and here.

Within HK2 itself the important changes within this PR seem to be working on the MethodModel within the ModelClassVisitor (here). This code is preceded by reading the method signature (which is where this MethodSignatureVisitorImpl class comes into play), during which at least one code path seems to "visit" the exception type (which is where I start getting lost without a debugger).

[avpinchuk]

@Pandrex247, list exceptionTypes at L39 always stay empty because it never updated.

[pzygielo]

list exceptionTypes at L39 always stay empty because it never updated.

Probably we don't know. getExceptionTypes returns original, mutable list so this MIGHT be updated anywhere, out of control of the class.
I understand getParameters does the same.

[avpinchuk]

I understand getParameters does the same.

But parameters collection is filled in the visitParameterType() method at L63 of the MethodSignatureVisitorImpl class.

Actual exception types processing occurs in the ModelClassVisitor class beginnin with L284.

mutable list so this MIGHT be updated anywhere, out of control of the class.

In this case even out of control HK2.