public interface UserService {
 public User findById(int id);
 public User create(User user);
 public User update(User user);
 public void delete(int id);
}

@Servicepublic class UserServiceImpl implements UserService {
 @Autowired
 private UserRepository userRepository;
 @Autowired
 private UserRedis userRedis;
 //this is a key for redis
 private static final String keyHead = "mysql:get:user:";

 @Override
 public User findById(int id) {
  User user = userRedis.get(keyHead+id);
  if (user == null) {
   user = userRepository.findOne(id);
   if (user != null) {
    userRedis.add(keyHead+id, 30L, user);
   }
  }
  return user;
 }

 @Override
 public User create(User user) {
  User newUser = userRepository.save(user);
  if (newUser != null) {
   userRedis.add(keyHead+newUser.getId(), 30L, newUser);
  }
  return newUser;
 }

 @Override
 public User update(User user) {
  if (user != null) {
   userRedis.delete(keyHead+user.getId());
   userRedis.add(keyHead+user.getId(), 30L, user);
  }
  return userRepository.save(user);
 }

 @Override
 public void delete(int id) {
  userRedis.delete(keyHead+id);
  userRepository.delete(id);
 }
}

@RestController
@RequestMapping("/users")
public class UserController {
 @Autowired
 private UserService userService;
 @RequestMapping(value = "/{id}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
 public Object show(@PathVariable int id) {
  User user = userService.findById(id);
  return user;
 }
}