Microservices with Spring Cloud

package com.example.demo.service;

import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker;
import io.github.resilience4j.retry.annotation.Retry;
import io.github.resilience4j.timelimiter.annotation.TimeLimiter;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import java.util.concurrent.CompletableFuture;

@Service
public class ResilientService {

    private final RestTemplate restTemplate;

    public ResilientService(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    @CircuitBreaker(name = "userService", fallbackMethod = "fallbackGetUser")
    @Retry(name = "userService")
    public User getUser(Long id) {
        String url = "http://user-service/api/users/" + id;
        return restTemplate.getForObject(url, User.class);
    }

    @TimeLimiter(name = "userService")
    @CircuitBreaker(name = "userService", fallbackMethod = "fallbackGetUserAsync")
    public CompletableFuture<User> getUserAsync(Long id) {
        return CompletableFuture.supplyAsync(() -> {
            String url = "http://user-service/api/users/" + id;
            return restTemplate.getForObject(url, User.class);
        });
    }

    private User fallbackGetUser(Long id, Exception ex) {
        System.err.println("Fallback for user " + id + ": " + ex.getMessage());
        User user = new User();
        user.setId(id);
        user.setName("Fallback User");
        return user;
    }

    private CompletableFuture<User> fallbackGetUserAsync(Long id, Exception ex) {
        return CompletableFuture.completedFuture(fallbackGetUser(id, ex));
    }
}

spring:
  application:
    name: user-service
  cloud:
    config:
      uri: http://config-server:8888
      fail-fast: true

eureka:
  client:
    serviceUrl:
      defaultZone: http://eureka-server:8761/eureka/
    fetch-registry: true
    register-with-eureka: true
  instance:
    prefer-ip-address: true

resilience4j:
  circuitbreaker:
    instances:
      userService:
        registerHealthIndicator: true
        slidingWindowSize: 10
        minimumNumberOfCalls: 5
        permittedNumberOfCallsInHalfOpenState: 3
        automaticTransitionFromOpenToHalfOpenEnabled: true
        waitDurationInOpenState: 5s
        failureRateThreshold: 50
        eventConsumerBufferSize: 10

  retry:
    instances:
      userService:
        maxAttempts: 3
        waitDuration: 1s

  timelimiter:
    instances:
      userService:
        timeoutDuration: 2s