Nayha

 @GetMapping("/GetkobisData")
    public String callAPI() throws JsonProcessingException {
 
        HashMap<String, Object> result = new HashMap<String, Object>();
 
        String jsonInString = "";
 
        try {
 
            HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();
            factory.setConnectTimeout(5000); //타임아웃 설정 5초
            factory.setReadTimeout(5000);//타임아웃 설정 5초
            RestTemplate restTemplate = new RestTemplate(factory);
 
            HttpHeaders header = new HttpHeaders();
            HttpEntity<?> entity = new HttpEntity<>(header);
 
            String url = "http://www.kobis.or.kr/kobisopenapi/webservice/rest/boxoffice/searchDailyBoxOfficeList.json";
 
            UriComponents uri = UriComponentsBuilder.fromHttpUrl(url+"?"+"key=430156241533f1d058c603178cc3ca0e&targetDt=20120101").build();
 
            //이 한줄의 코드로 API를 호출해 MAP타입으로 전달 받는다.
            ResponseEntity<Map> resultMap = restTemplate.exchange(uri.toString(), HttpMethod.GET, entity, Map.class);
            result.put("statusCode", resultMap.getStatusCodeValue()); //http status code를 확인
            result.put("header", resultMap.getHeaders()); //헤더 정보 확인
            result.put("body", resultMap.getBody()); //실제 데이터 정보 확인
 
            //데이터를 제대로 전달 받았는지 확인 string형태로 파싱해줌
            ObjectMapper mapper = new ObjectMapper();
            jsonInString = mapper.writeValueAsString(resultMap.getBody());
 
        } catch (HttpClientErrorException | HttpServerErrorException e) {
            result.put("statusCode", e.getRawStatusCode());
            result.put("body"  , e.getStatusText());
            System.out.println("dfdfdfdf");
            System.out.println(e.toString());
 
        } catch (Exception e) {
            result.put("statusCode", "999");
            result.put("body"  , "excpetion오류");
            System.out.println(e.toString());
        }
 
        return jsonInString;
 
    }

출처.. https://vmpo.tistory.com/27

response 고민하지 말고 한방에 이걸로..