PaymentController.java

package com.bravo.user.controller;

import com.bravo.user.annotation.SwaggerController;
import com.bravo.user.exception.BadRequestException;
import com.bravo.user.model.dto.PaymentDto;
import com.bravo.user.service.PaymentService;
import com.bravo.user.validator.UserValidator;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@RequestMapping(value = "/payment")
@SwaggerController
public class PaymentController {

    private final PaymentService paymentService;
    private final UserValidator userValidator;

    public PaymentController(PaymentService paymentService, UserValidator userValidator) {
        this.paymentService = paymentService;
        this.userValidator = userValidator;
    }

    @GetMapping(value = "/retrieve")
    @ResponseBody
    public List<PaymentDto> retrieve(
            final @RequestParam(required = false) String userId
    ) {
        if (userId != null) {
            userValidator.validateId(userId);
            return paymentService.retrieveByUserId(userId);
        } else {
            throw new BadRequestException("'user id' is required!");
        }
    }

}