Call a REST end-point from another

Question

I have a REST endpoint provided below,

    @PutMapping("/calculateReward")
    public ResponseEntity<String> calculateReward(@RequestParam("userId") Long userId) {

        Optional<User> optional = userService.findById(userId);

        if (!optional.isPresent()) {
            return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
        }

        User user = optional.get();

        double reward = user.getCurrentSteps() * Parameters.REWARD_PER_STEPS_EUR;

        RewardList list = new RewardList();

        list.setUser(user);
        list.setReward(reward);

        user.setCurrentSteps(0);
        user.setRewardLists(list);

        userService.save(user);
        rewardListService.save(list);

        JSONObject json = new JSONObject();

        double convertionRateToEuro = currencyMap.get(user.getCurrencyName());
        double rewardConverted = reward * convertionRateToEuro;

        json.put("name", user.getName());
        json.put("currency", user.getCurrencyName());
        json.put("reward", rewardConverted);

        return ResponseEntity.status(HttpStatus.CREATED).body(json.toString());
    }

ATM I work into another end-point where I need to have the reward value from the end-point provided above.

    @PostMapping("/paypal/make/payment")
    public ResponseEntity<String> paymentUsingPaypal(@RequestParam("userId") Long userId) {

        Optional<User> optional = userService.findById(userId);

        if (!optional.isPresent()) {
            return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
        }

        User user = optional.get();


        // How do I get the "reward" in double here?
    }

How do I get the "reward" in double from the calculateReward method in the end of the 2nd method?

Answer 1

If it's the same application, why not just calling:

nameOfController.calculateReward(userId);

If you can't call the method, you would have to write a client using for example feign .