Possible incorrect TypeVariable resolution in TypeParameterResolver

[huan0huan]

why not equals？ This is bug ?

[harawata]

Please explain how to reproduce the problem.

[huan0huan]

I load mapper on my first visit after startup, which may occur when multithreaded access occurs

[harawata]

Please create a small demo project so that we can replicate the issue on our end.
Here are some project templates to start with. https://github.com/harawata/mybatis-issues

[huan0huan]

I've uploaded it。see https://github.com/huan0huan/all-problem

[harawata]

Thank you very much for the repro, @huan0huan !

You are right. The javadoc says:

Multiple objects may be instantiated at run-time to represent a given type variable. Even though a type variable is created only once, this does not imply any requirement to cache instances representing the type variable. However, all instances representing a type variable must be equal() to each other. As a consequence, users of type variables must not rely on the identity of instances of classes implementing this interface.

The fix is in the latest 3.5.4-SNAPSHOT.
Please let me know if you noticed anything!