public class GetRuntimeParameterName {

 public void createUser(String name, int age, int version) {
  //
 }

 public static void main(String[] args) throws Exception {
  for (Method m : GetRuntimeParameterName.class.getMethods()) {
   System.out.println("----------------------------------------");
   System.out.println(" method: " + m.getName());
   System.out.println(" return: " + m.getReturnType().getName());
   for (Parameter p : m.getParameters()) {
    System.out.println("parameter: " + p.getType().getName() + ", " + p.getName());
   }
  }
 }
}

 method: createUser
 return: void
parameter: java.lang.String, name
parameter: int, age
parameter: int, version

@Path("/groups/:groupid/:userid")
public User getUser(String groupid, String userid) {
 ...
}

@Path("/groups/:groupid/:userid")
public User getUser(@Param("groupid") String groupid, @Param("userid") String userid) {
 ...
}