Some means of doing parameters

I'm doing an implementation of Swagger 2.0, and Swagger uses JSON Schema to describe not only incoming and outgoing JSON, but also the constraints on any parameters in your REST methods. For example:

public String myRestMethod(@NotNull @Min(3) int myNumber) {}

The definition of "myNumber" would be identical to that of a property of a class that had these annotations.

It would really convenient if I could pass in a Java Method or perhaps a JDK 1.8 Parameter object and get JSON Schema for parameters.

Hibernate Validator did exactly this: http://docs.jboss.org/hibernate/stable/validator/reference/en-US/html_single/#chapter-method-constraints