Exception documenting RestControllerEndpoint with PostMapping

[p120ph37]

When a @RestControllerEndpoint bean defines a @PostMapping method and springdoc-openapi tries to introspect it, the following exception is thrown:

java.lang.NullPointerException: Cannot invoke "java.lang.reflect.Field.get(Object)" because "operationFiled" is null
        at org.springdoc.core.customizers.ActuatorOperationCustomizer.customize(ActuatorOperationCustomizer.java:84) ~[springdoc-openapi-common-1.6.9.jar:1.6.9]

This is the line in question: v1.6.9 ActuatorOperationCustomizer.java L84

This seems to have been introduced in this commit: 6ce3b5a

The issue is present in version 1.6.7 and later. Reverting to version 1.6.6 fixes it for me.

[bnasslahsen]

@p120ph37,

I have added a fix, just from coding perspective;
But was not able to reproduce your error. I are able to propose a PR, with the related test case, it would be great.