public void setFirstName(Vet obj, int index) {
   String firstName = "firstName_" + index;
   if (firstName.length() > 30) {
     firstName = firstName.substring(0, 30);
   }
   obj.setFirstName(firstName);
 }
  public static void main(String args[]) throws JAXBException {
    ServiceRequest<Vet> serviceRequest = new ServiceRequest<Vet>();
    serviceRequest.setChannelId("001");
    serviceRequest.setRequestTime(new DateTime());
    serviceRequest.addRequestParam("afdas", "asdfasd");
    serviceRequest.addRequestParam("asdfasd", "afsd");
    serviceRequest.addRequestParam("dasf", "safd");

    Vet vets = new Vet();
    vets.setFirstName("Farhan");
    serviceRequest.setPayLoad(vets);

    //
    //        ApplicationContext context = new
    // ClassPathXmlApplicationContext("applicationContext.xml");
    //        PetClinicManagerBase service =  context.getBean(PetClinicManagerImpl.class);
    //        Result<List<PetType>> owner = service.findAllPetTypes();
    // main(). response.setResult(owner);
    JAXBContext jaxbContext = JAXBContext.newInstance(ServiceRequest.class);
    Marshaller marshaller = jaxbContext.createMarshaller();
    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
    marshaller.marshal(serviceRequest, System.out);
  }