@GetMapping("/owners/{ownerId}")
    public ModelAndView showOwner(@PathVariable("ownerId") int ownerId) {
        ModelAndView mav = new ModelAndView("owners/ownerDetails");
        mav.addObject(this.clinicService.findOwnerById(ownerId));
        return mav;
    }
Custom handler for displaying an owner.

@param ownerId the ID of the owner to display
@return a ModelMap with the model attributes for the view
src/main/java/org/springframework/samples/petclinic/web/OwnerController.java