[코디'ing] firebase를 사용해보자

팀프로젝트 과정에서 좋아요가 눌렸을 경우 알림이 오도록 하기 위해서 firebase를 사용해야했다.

NotificationService.java

@Component
@RequiredArgsConstructor
public class NotificationService {

    private final String API_URL = "";
    private final ObjectMapper objectMapper;

    public void sendMessageTo(String targetToken, String title, String body) throws IOException {
        String message = makeMessage(targetToken, title, body);

        OkHttpClient client = new OkHttpClient();
        RequestBody requestBody = RequestBody.create(message,
                MediaType.get("application/json; charset=utf-8"));
        Request request = new Request.Builder()
                .url(API_URL)
                .post(requestBody)
                .addHeader(HttpHeaders.AUTHORIZATION, "Bearer " + getAccessToken())
                .addHeader(HttpHeaders.CONTENT_TYPE, "application/json; UTF-8")
                .build();

        Response response = client.newCall(request).execute();

        System.out.println(response.body().string());
    }

    private String makeMessage(String targetToken, String title, String body) throws JsonParseException, JsonProcessingException {
        NotificationMessage notificationMessage = NotificationMessage.builder()
                .message(NotificationMessage.Message.builder()
                        .token(targetToken)
                        .notification(NotificationMessage.Notification.builder()
                                .title(title)
                                .body(body)
                                .image(null)
                                .build()
                        ).build()).validateOnly(false).build();

        return objectMapper.writeValueAsString(notificationMessage);
    }

    private String getAccessToken() throws IOException {
        String firebaseConfigPath = "firebase_service_key.json";

        GoogleCredentials googleCredentials = GoogleCredentials
                .fromStream(new ClassPathResource(firebaseConfigPath).getInputStream())
                .createScoped(List.of(""));

        googleCredentials.refreshIfExpired();
        return googleCredentials.getAccessToken().getTokenValue();
    }

    @Scheduled(fixedRate = 60000)  // 예: 1분마다 실행
    public void sendPeriodicNotifications() {
        // 알림을 보내는 로직
    }
    public void sendLikeNotification(Long postId) {
    }

    public void sendTopPostNotification(Long postId) {
    }

}

NotificationMessage.java

@Builder
@AllArgsConstructor
@Getter
public class NotificationMessage {
    private boolean validateOnly;
    private Message message;

    @Builder
    @AllArgsConstructor
    @Getter
    public static class Message {
        private Notification notification;
        private String token;
    }

    @Builder
    @AllArgsConstructor
    @Getter
    public static class Notification {
        private String title;
        private String body;
        private String image;
    }
}

NotificationRequest.java

@Getter
@Setter
public class NotificationRequest {
    private String targetToken;
    private String title;
    private String body;
}