@Override
 public List<SupplierDTO> getAllSuppliers() {
   List<SupplierDTO> supplierDtos = new ArrayList<SupplierDTO>();
   List<Supplier> suppliers = supplierDAO.findAll();
   if (suppliers != null && !suppliers.isEmpty()) {
     for (Supplier supplier : suppliers) {
       SupplierDTO supplierDTO = new SupplierDTO();
       BeanUtils.copyProperties(supplier, supplierDTO);
       supplierDtos.add(supplierDTO);
     }
   }
   return supplierDtos;
 }