feat/#45: 학생회 게시글 작성 시, 학생에게 푸시알림 기능 구현

build.gradle

@@ -57,6 +57,9 @@ dependencies {
     //HTTP 클라이언트
     implementation 'com.oracle.oci.sdk:oci-java-sdk-common-httpclient-jersey3'
 
+    // Firebase Admin SDK
+    implementation 'com.google.firebase:firebase-admin:9.7.0'
+
     compileOnly 'org.projectlombok:lombok'
     developmentOnly 'org.springframework.boot:spring-boot-devtools'
     runtimeOnly 'com.mysql:mysql-connector-j'

src/main/java/com/campus/campus/domain/council/domain/entity/CouncilType.java

@@ -9,21 +9,32 @@ public boolean hasAccess(User user, StudentCouncil writer) {
 			return user.getSchool() != null &&
 				user.getSchool().getSchoolId().equals(writer.getSchool().getSchoolId());
 		}
+
+		@Override public String topic(StudentCouncil writer) {
+			return "school_" + writer.getSchool().getSchoolId();
+		}
 	},
 	COLLEGE_COUNCIL {
 		@Override
 		public boolean hasAccess(User user, StudentCouncil writer) {
 			return user.getCollege() != null &&
 				user.getCollege().getCollegeId().equals(writer.getCollege().getCollegeId());
 		}
+		@Override public String topic(StudentCouncil writer) {
+			return "college_" + writer.getCollege().getCollegeId();
+		}
 	},
 	MAJOR_COUNCIL {
 		@Override
 		public boolean hasAccess(User user, StudentCouncil writer) {
 			return user.getMajor() != null &&
 				user.getMajor().getMajorId().equals(writer.getMajor().getMajorId());
 		}
+		@Override public String topic(StudentCouncil writer) {
+			return "major_" + writer.getMajor().getMajorId();
+		}
 	};
 
 	public abstract boolean hasAccess(User user, StudentCouncil writer);
+	public abstract String topic(StudentCouncil writer);
 }

src/main/java/com/campus/campus/domain/councilpost/application/CouncilPostPushListener.java

@@ -0,0 +1,57 @@
+package com.campus.campus.domain.councilpost.application;
+
+import java.util.Map;
+
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+import com.campus.campus.domain.councilpost.application.dto.request.CouncilPostCreatedEvent;
+import com.campus.campus.global.firebase.application.service.FirebaseCloudMessageService;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class CouncilPostPushListener {
+
+	private static final String DATA_KEY_TYPE = "type";
+	private static final String DATA_TYPE_COUNCIL_POST_CREATED = "COUNCIL_POST_CREATED";
+	private static final String DATA_KEY_POST_ID = "postId";
+	private static final String DATA_KEY_CATEGORY = "category";
+
+	private final FirebaseCloudMessageService firebaseCloudMessageService;
+
+	@Async
+	@TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
+	public void handleCouncilPostCreatedEvent(CouncilPostCreatedEvent event) {
+
+		String title = event.councilName();
+		String body = resolveBody(event.category());
+
+		log.info("[PUSH] after_commit event received. topic={}, postId={}, category={}",
+			event.topic(), event.postId(), event.category());
+
+		firebaseCloudMessageService.sendToTopic(
+			event.topic(),
+			title,
+			body,
+			Map.of(
+				DATA_KEY_TYPE, DATA_TYPE_COUNCIL_POST_CREATED,
+				DATA_KEY_POST_ID, String.valueOf(event.postId()),
+				DATA_KEY_CATEGORY, event.category()
+			)
+		);
+	}
+
+	private String resolveBody(String category) {
+		return switch (category) {
+			case "PARTNERSHIP" -> "새 제휴 게시글이 등록되었습니다.";
+			case "EVENT" -> "새 행사글이 등록되었습니다.";
+			default -> "새 게시글이 등록되었습니다.";
+		};
+	}
+}

src/main/java/com/campus/campus/domain/councilpost/application/dto/request/CouncilPostCreatedEvent.java

@@ -0,0 +1,8 @@
+package com.campus.campus.domain.councilpost.application.dto.request;
+
+public record CouncilPostCreatedEvent(
+	Long postId,
+	String councilName,
+	String category,
+	String topic
+) {}

src/main/java/com/campus/campus/domain/councilpost/application/service/StudentCouncilPostForUserService.java

@@ -4,7 +4,6 @@
 import java.time.ZoneId;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Optional;
 import java.util.Set;
 
 import org.springframework.dao.DataIntegrityViolationException;
@@ -18,9 +17,9 @@
 import com.campus.campus.domain.council.domain.entity.CouncilType;
 import com.campus.campus.domain.councilpost.application.dto.response.GetActivePartnershipListForUserResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.GetLikedPostResponse;
+import com.campus.campus.domain.councilpost.application.dto.response.GetPostForUserResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.LikePostResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.PostListItemResponse;
-import com.campus.campus.domain.councilpost.application.dto.response.GetPostForUserResponse;
 import com.campus.campus.domain.councilpost.application.exception.CollegeNotSetException;
 import com.campus.campus.domain.councilpost.application.exception.MajorNotSetException;
 import com.campus.campus.domain.councilpost.application.exception.PostNotFoundException;

src/main/java/com/campus/campus/domain/councilpost/application/service/StudentCouncilPostService.java

@@ -4,6 +4,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
@@ -14,11 +15,12 @@
 import com.campus.campus.domain.council.application.exception.StudentCouncilNotFoundException;
 import com.campus.campus.domain.council.domain.entity.StudentCouncil;
 import com.campus.campus.domain.council.domain.repository.StudentCouncilRepository;
+import com.campus.campus.domain.councilpost.application.dto.request.CouncilPostCreatedEvent;
+import com.campus.campus.domain.councilpost.application.dto.request.PostRequest;
 import com.campus.campus.domain.councilpost.application.dto.response.GetPostListForCouncilResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.GetPostResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.GetUpcomingEventListForCouncilResponse;
 import com.campus.campus.domain.councilpost.application.dto.response.NormalizedDateTime;
-import com.campus.campus.domain.councilpost.application.dto.request.PostRequest;
 import com.campus.campus.domain.councilpost.application.exception.NotPostWriterException;
 import com.campus.campus.domain.councilpost.application.exception.PostImageLimitExceededException;
 import com.campus.campus.domain.councilpost.application.exception.PostNotFoundException;
@@ -45,6 +47,7 @@ public class StudentCouncilPostService {
 	private final PostImageRepository postImageRepository;
 	private final PresignedUrlService presignedUrlService;
 	private final StudentCouncilPostMapper studentCouncilPostMapper;
+	private final ApplicationEventPublisher eventPublisher;
 
 	private static final int MAX_IMAGE_COUNT = 10;
 	private static final long UPCOMING_EVENT_WINDOW_HOURS = 72L;
@@ -69,14 +72,24 @@ public GetPostResponse create(Long councilId, PostRequest dto) {
 			writer, dto, normalized.startDateTime(), normalized.endDateTime()
 		);
 
-		postRepository.save(post);
+		StudentCouncilPost saved = postRepository.save(post);
 
 		if (dto.imageUrls() != null) {
 			for (String imageUrl : dto.imageUrls()) {
 				postImageRepository.save(studentCouncilPostMapper.createPostImage(post, imageUrl));
 			}
 		}
 
+		String topic = writer.getCouncilType().topic(writer);
+		String writerName = writer.getCouncilName();
+
+		eventPublisher.publishEvent(new CouncilPostCreatedEvent(
+			saved.getId(),
+			writerName,
+			saved.getCategory().name(),
+			topic
+		));
+
 		List<String> imageUrls = postImageRepository
 			.findAllByPostOrderByIdAsc(post)
 			.stream()

src/main/java/com/campus/campus/domain/councilpost/domain/repository/LikePostRepository.java

@@ -1,7 +1,6 @@
 package com.campus.campus.domain.councilpost.domain.repository;
 
 import java.util.List;
-import java.util.Optional;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;

src/main/java/com/campus/campus/domain/councilpost/presentation/StudentCouncilPostController.java

@@ -1,5 +1,7 @@
 package com.campus.campus.domain.councilpost.presentation;
 
+import java.util.Map;
+
 import org.springframework.data.domain.Page;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -20,6 +22,7 @@
 import com.campus.campus.domain.councilpost.domain.entity.PostCategory;
 import com.campus.campus.global.annotation.CurrentCouncilId;
 import com.campus.campus.global.common.response.CommonResponse;
+import com.campus.campus.global.firebase.application.service.FirebaseCloudMessageService;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
@@ -37,7 +40,7 @@
 public class StudentCouncilPostController {
 
 	private final StudentCouncilPostService postService;
-
+	private final FirebaseCloudMessageService firebaseCloudMessageService;
 	@PostMapping
 	@Operation(
 		summary = "학생회 제휴/행사 게시글 생성",
@@ -164,4 +167,15 @@ public CommonResponse<Page<GetUpcomingEventListForCouncilResponse>> getUpcomingE
 
 		return CommonResponse.success(StudentCouncilPostResponseCode.POST_LIST_READ_SUCCESS, response);
 	}
+
+
+	@PostMapping("/topic/{topic}")
+	public void sendToTopic(@PathVariable String topic) {
+		firebaseCloudMessageService.sendToTopic(
+			topic,
+			"푸시 테스트",
+			"서버에서 보낸 테스트 알림입니다.",
+			Map.of("type", "TEST")
+		);
+	}
 }

src/main/java/com/campus/campus/global/config/AsyncConfig.java

@@ -0,0 +1,9 @@
+package com.campus.campus.global.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableAsync;
+
+@Configuration
+@EnableAsync
+public class AsyncConfig {
+}

src/main/java/com/campus/campus/global/firebase/application/dto/FcmMessageRequestDto.java

@@ -0,0 +1,17 @@
+package com.campus.campus.global.firebase.application.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+
+public record FcmMessageRequestDto(
+
+	@Schema(description = "유저ID", example = "1")
+	Long userId,
+
+	@Schema(description = "메시지 발송인", example = "시스템")
+	String title,
+
+	@Schema(description = "메시지 내용", example = "이제 서연님에게 화이팅을 할 수 있어요.")
+	String body
+) {
+}

src/main/java/com/campus/campus/global/firebase/application/service/FirebaseCloudMessageService.java

@@ -0,0 +1,53 @@
+package com.campus.campus.global.firebase.application.service;
+
+import java.util.Map;
+
+import org.springframework.stereotype.Service;
+
+import com.campus.campus.global.firebase.exception.FcmTopicSendFailedException;
+import com.google.firebase.messaging.FirebaseMessaging;
+import com.google.firebase.messaging.FirebaseMessagingException;
+import com.google.firebase.messaging.Message;
+import com.google.firebase.messaging.Notification;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class FirebaseCloudMessageService {
+
+	public void sendToTopic(String topic, String title, String body, Map<String, String> data) {
+		Message.Builder builder = Message.builder()
+			.setTopic(topic)
+			.setNotification(Notification.builder()
+				.setTitle(title)
+				.setBody(body)
+				.build());
+
+		if (data != null) {
+			data.forEach(builder::putData);
+		}
+
+		try {
+			String messageId = FirebaseMessaging.getInstance().send(builder.build());
+			log.info("[FCM] sent. topic={}, messageId={}, title={}, body={}, dataKeys={}",
+				topic,
+				messageId,
+				title,
+				body,
+				(data == null ? "[]" : data.keySet().toString())
+			);
+
+		} catch (FirebaseMessagingException e) {
+			log.error("[FCM] send failed. topic={}, errorCode={}, message={}",
+				topic,
+				e.getErrorCode(),
+				e.getMessage(),
+				e
+			);
+			throw new FcmTopicSendFailedException(e);
+		}
+	}
+}

src/main/java/com/campus/campus/global/firebase/application/service/FirebaseInitializer.java

@@ -0,0 +1,36 @@
+package com.campus.campus.global.firebase.application.service;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.stereotype.Service;
+
+import com.campus.campus.global.firebase.exception.FirebaseInitializationFailedException;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.firebase.FirebaseApp;
+import com.google.firebase.FirebaseOptions;
+
+@Service
+public class FirebaseInitializer {
+
+	@PostConstruct
+	public void initialize() {
+		if (!FirebaseApp.getApps().isEmpty()) {
+			return;
+		}
+
+		try (InputStream serviceAccount = new ClassPathResource("keys/campus-firebase.json").getInputStream()) {
+
+			FirebaseOptions options = FirebaseOptions.builder()
+				.setCredentials(GoogleCredentials.fromStream(serviceAccount))
+				.build();
+			FirebaseApp.initializeApp(options);
+
+		} catch (IOException e) {
+			throw new FirebaseInitializationFailedException();
+		}
+	}
+}

src/main/java/com/campus/campus/global/firebase/exception/ErrorCode.java

@@ -0,0 +1,20 @@
+package com.campus.campus.global.firebase.exception;
+
+import org.springframework.http.HttpStatus;
+
+import com.campus.campus.global.common.exception.ErrorCodeInterface;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum ErrorCode implements ErrorCodeInterface {
+
+	FIREBASE_INITIALIZATION_FAILED(6201, HttpStatus.INTERNAL_SERVER_ERROR, "Firebase 초기화에 실패했습니다."),
+	FCM_TOPIC_SEND_FAILED(6202, HttpStatus.INTERNAL_SERVER_ERROR, "푸시 알림 전송에 실패했습니다.");
+
+	private final int code;
+	private final HttpStatus status;
+	private final String message;
+}

src/main/java/com/campus/campus/global/firebase/exception/FcmTopicSendFailedException.java

@@ -0,0 +1,7 @@
+package com.campus.campus.global.firebase.exception;
+
+public class FcmTopicSendFailedException extends RuntimeException {
+	public FcmTopicSendFailedException(Throwable cause) {
+		super(ErrorCode.FCM_TOPIC_SEND_FAILED.getMessage(), cause);
+	}
+}

src/main/java/com/campus/campus/global/firebase/exception/FirebaseInitializationFailedException.java

@@ -0,0 +1,7 @@
+package com.campus.campus.global.firebase.exception;
+
+public class FirebaseInitializationFailedException extends RuntimeException {
+	public FirebaseInitializationFailedException() {
+		super(ErrorCode.FIREBASE_INITIALIZATION_FAILED.getMessage());
+	}
+}