The dependencies of some of the beans in the application context form a cycle:

Error

• rest template을 다음과 같이 사용했을 때 Error가 발생했다.

• service 인터페이스

    package kr.pe.playdata.service;
      
    import java.util.concurrent.CompletableFuture;
      
    public interface RecommandService {
        /*
            관광지 추천 서비스 인터페이스
         */
      
        public CompletableFuture<String> recommand(String keywords);
    }
  

• service 구현

    package kr.pe.playdata.service.impl;
      
    import kr.pe.playdata.service.RecommandService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.scheduling.annotation.Async;
    import org.springframework.stereotype.Service;
    import org.springframework.util.LinkedMultiValueMap;
    import org.springframework.util.MultiValueMap;
    import org.springframework.web.client.RestTemplate;
    import java.util.concurrent.CompletableFuture;
      
    @Service
    public class RecommandServiceImpl implements RecommandService {
        /*
            관광지를 추천해주는 서비스 구현체
         */
      
        @Autowired
        private RestTemplate restTemplate;
      
    		@Bean
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }
      
        @Async("asyncExecutor")
        public CompletableFuture<String> recommand(String keywords){
            String url = "http://127.0.0.1:5000/recommand";
            MultiValueMap<String, String> param = new LinkedMultiValueMap<String, String>();
            param.add("keywords",keywords);
            String sb = restTemplate.postForObject(url, param, String.class);
            return CompletableFuture.completedFuture(sb);
        }
    }
  

• Error 발생

  

Error 해결

• RestTemplate Config를 만들어 RestTemplate을 미리 Bean에 등록하였다.

    package kr.pe.playdata.config;
      
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;
      
    @Configuration
    public class RestTemplateConfig {
        /*
            rest Config
         */
      
        @Bean
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }
    }
  

참고 사이트

Circular Dependency in Spring Boot