Spring Boot - Slack Message 전송 API 구현

프로젝트에서 슬랙 메시지를 전송하는 요건이 있어 알아보게 되었음

Slack Incoming WebHooks 설정

• 더보기 - 자동화 - 앱 - Incoming WebHooks 추가
• App 설정 이동
• 구성 편집
• 웹후크 URL 복사

RestTemplate 설정

• RestTemplate을 이용해 메시지를 전송할 예정이므로 RestTemplateConfig 설정

  @Configuration
  public class RestTemplateConfig {
      @Bean
      public RestTemplate slackRestTemplate(){
          return new RestTemplate();
      }
  }

서비스 로직 구현

• ReqDto

  @Data
  @NoArgsConstructor
  @AllArgsConstructor
  public class SlackIncomingHookDto {
      private String channel;
      private String text;
  }

• ResDto

  @Getter
  @Builder
  @NoArgsConstructor
  @AllArgsConstructor
  public class SlackMessageResDto {
      Long id;
      String receiverId;
      String message;
      LocalDateTime sendTime;
  
      public static SlackMessageResDto from (Slack slack){
          return SlackMessageResDto.builder()
                  .id(slack.getId())
                  .receiverId(slack.getReceiverId())
                  .message(slack.getMessage())
                  .sendTime(slack.getSendTime())
                  .build();
      }
  }

• Slack Entity

  @Getter
  @Builder
  @NoArgsConstructor
  @AllArgsConstructor
  @Entity(name = "p_slacks")
  public class Slack {
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      Long id;
  
      String receiverId;
  
      @Column(length = 1000)
      String message;
  
      LocalDateTime sendTime;
  }

• SlackRepository

  public interface SlackRepository extends JpaRepository<Slack, Long> {
  }

• SlackService

  @Service
  @RequiredArgsConstructor
  @Slf4j(topic = "SlackService")
  @Transactional(readOnly = true)
  public class SlackService {
  
      private final SlackRepository slackRepository;
      private final RestTemplate slackRestTemplate;
  
      @Value("${slack.incoming-hook.url}")
      String slackURL;
  
      @Transactional
      public SlackMessageResDto sendSlackMessage(SlackMessageReqDto slackMessageReqDto) {
          try{
              SlackIncomingHookDto request = new SlackIncomingHookDto("@"+slackMessageReqDto.getReceiverId(), slackMessageReqDto.getMessage());
              log.info(slackRestTemplate.postForObject(slackURL, request, String.class));
              return SlackMessageResDto.from(slackRepository.save(slackMessageReqDto.toEntity(LocalDateTime.now())));
          }catch (Exception e){
              log.error("Internal Server Error");
              throw new CoreApiException(ErrorType.DEFAULT_ERROR);
          }
      }
  }

  • slackURL에 복사해둔 IncomingWebHook의 URL 입력 ( 외부에 노출되지 않도록 주의!! )
  • “@”의 경우 DM을 보내기위해 덧붙인 부분이므로 채널에 전송을 원하면 “@”을 제외하고 채널 명 입력하면 됨