I'm think you try to solve wrong task. It's really unusual decision to map servlet on wildcard like this. Take a look on Spring MVC framework there you can write methods like this
@RequestMapping("/owners/{ownerId}/pets/{petId}", method=RequestMethod.GET)
public String findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {
Owner owner = ownerService.findOwner(ownderId);
Pet pet = owner.getPet(petId);
model.addAttribute("pet", pet);
return "displayPet";
}