[FIX] 방 관리 기능 개선 및 버그 수정 (+ 채팅 refactor)

src/main/java/com/project/dorumdorum/domain/chat/application/dto/response/NotificationMessage.java

@@ -0,0 +1,15 @@
+package com.project.dorumdorum.domain.chat.application.dto.response;
+
+public record NotificationMessage(
+        String type,
+        String roomNo,
+        String chatRoomNo
+) {
+    public static NotificationMessage roomDeleted(String roomNo, String chatRoomNo) {
+        return new NotificationMessage("ROOM_DELETED", roomNo, chatRoomNo);
+    }
+
+    public static NotificationMessage kicked(String roomNo, String chatRoomNo) {
+        return new NotificationMessage("KICKED_FROM_ROOM", roomNo, chatRoomNo);
+    }
+}

src/main/java/com/project/dorumdorum/domain/chat/application/event/RoomDeletedEventListener.java

@@ -0,0 +1,76 @@
+package com.project.dorumdorum.domain.chat.application.event;
+
+import com.project.dorumdorum.domain.chat.application.dto.response.NotificationMessage;
+import com.project.dorumdorum.domain.chat.domain.entity.ChatRoom;
+import com.project.dorumdorum.domain.chat.domain.entity.ChatRoomType;
+import com.project.dorumdorum.domain.chat.domain.service.ChatMessageService;
+import com.project.dorumdorum.domain.chat.domain.service.ChatRoomMemberService;
+import com.project.dorumdorum.domain.chat.domain.service.ChatRoomService;
+import com.project.dorumdorum.domain.room.application.event.RoomDeletedEvent;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+import java.util.List;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class RoomDeletedEventListener {
+
+    private final ChatRoomService chatRoomService;
+    private final ChatRoomMemberService chatRoomMemberService;
+    private final ChatMessageService chatMessageService;
+    private final SimpMessagingTemplate messagingTemplate;
+
+    /**
+     * 방 삭제(RoomDeletedEvent) → GROUP·DIRECT 채팅방 전체 삭제 처리
+     * 발행: DeleteRoomUseCase (room 도메인 담당자)
+     *
+     * BEFORE_COMMIT: 부모 트랜잭션(DeleteRoomUseCase)에 참여하여 방 삭제 + 채팅방 삭제를 하나의 트랜잭션으로 처리.
+     * WebSocket 브로드캐스트는 트랜잭션 외부 작업이므로 실패가 TX에 영향을 주지 않도록 독립 처리.
+     */
+    @TransactionalEventListener(phase = TransactionPhase.BEFORE_COMMIT)
+    public void handle(RoomDeletedEvent event) {
+        List<ChatRoom> chatRooms = chatRoomService.findAllByRoomNo(event.roomNo());
+        for (ChatRoom chatRoom : chatRooms) {
+            notifyAndClean(chatRoom, event.roomNo());
+        }
+    }
+
+    private void notifyAndClean(ChatRoom chatRoom, String roomNo) {
+        NotificationMessage notification = NotificationMessage.roomDeleted(roomNo, chatRoom.getChatRoomNo());
+
+        // 채팅방 열려 있는 유저에게 브로드캐스트 (/topic/)
+        broadcastDeletionSafely(chatRoom, notification);
+
+        // DIRECT 채팅방은 지원자가 다른 화면에 있어도 받을 수 있도록 개인 큐로 추가 전송 (/queue/)
+        if (ChatRoomType.DIRECT.equals(chatRoom.getChatRoomType())
+                && chatRoom.getApplicantUserNo() != null) {
+            notifyUserSafely(chatRoom.getApplicantUserNo(), notification);
+        }
+
+        chatMessageService.deleteAllByChatRoom(chatRoom.getChatRoomNo());
+        chatRoomMemberService.deleteAllByChatRoom(chatRoom);
+        chatRoomService.deleteByChatRoomNo(chatRoom.getChatRoomNo());
+    }
+
+    private void broadcastDeletionSafely(ChatRoom chatRoom, NotificationMessage notification) {
+        try {
+            messagingTemplate.convertAndSend("/topic/chat-room/" + chatRoom.getChatRoomNo(), notification);
+        } catch (Exception e) {
+            log.warn("[Chat] 방 삭제 WebSocket 브로드캐스트 실패. chatRoomNo={}", chatRoom.getChatRoomNo(), e);
+        }
+    }
+
+    private void notifyUserSafely(String userNo, NotificationMessage notification) {
+        try {
+            messagingTemplate.convertAndSendToUser(userNo, "/queue/notification", notification);
+        } catch (Exception e) {
+            log.warn("[Chat] 개인 알림 전송 실패. userNo={}", userNo, e);
+        }
+    }
+}

src/main/java/com/project/dorumdorum/domain/chat/application/event/RoommateKickedEventListener.java

@@ -1,6 +1,7 @@
 package com.project.dorumdorum.domain.chat.application.event;
 
 import com.project.dorumdorum.domain.chat.application.dto.response.ChatMessageResponse;
+import com.project.dorumdorum.domain.chat.application.dto.response.NotificationMessage;
 import com.project.dorumdorum.domain.chat.domain.entity.ChatMessage;
 import com.project.dorumdorum.domain.chat.domain.entity.ChatRoom;
 import com.project.dorumdorum.domain.chat.domain.entity.ChatRoomMember;
@@ -41,25 +42,29 @@ public class RoommateKickedEventListener {
      */
     @TransactionalEventListener(phase = TransactionPhase.BEFORE_COMMIT)
     public void handle(RoommateKickedEvent event) {
-        chatRoomService.findByRoomNo(event.roomNo()).ifPresent(chatRoom -> {
-            if (chatRoomMemberService.isMember(chatRoom, event.kickedUserNo())) {
-                ChatRoomMember member = chatRoomMemberService.findByChatRoomAndUserNo(chatRoom, event.kickedUserNo());
-                LocalDateTime fromTime = member.getLastReadAt() != null
-                        ? member.getLastReadAt()
-                        : member.getJoinedAt();
-                chatMessageService.decreaseUnreadCount(chatRoom.getChatRoomNo(), fromTime, event.kickedUserNo());
-                chatRoomMemberService.leave(member);
-                User kicked = userService.findById(event.kickedUserNo());
-                String displayName = (kicked.getNickname() != null && !kicked.getNickname().isBlank())
-                        ? kicked.getNickname() : kicked.getName();
-                String content = displayName + "가 퇴장했습니다.";
-                ChatMessage message = chatMessageService.save(chatRoom, "SYSTEM", content, MessageType.SYSTEM, 0);
-                ChatMessageResponse response = new ChatMessageResponse(
-                        message.getMessageNo(), chatRoom.getChatRoomNo(),
-                        "SYSTEM", null, content, MessageType.SYSTEM.name(), message.getCreatedAt(), message.getUnreadCount());
-                broadcastSafely(chatRoom, response);
-            }
-        });
+        chatRoomService.findByRoomNo(event.roomNo()).ifPresent(chatRoom ->
+                chatRoomMemberService.findOptionalByChatRoomAndUserNo(chatRoom, event.kickedUserNo())
+                        .ifPresent(member -> processKick(chatRoom, member, event))
+        );
+    }
+
+    private void processKick(ChatRoom chatRoom, ChatRoomMember member, RoommateKickedEvent event) {
+        LocalDateTime fromTime = member.getLastReadAt() != null
+                ? member.getLastReadAt()
+                : member.getJoinedAt();
+        chatMessageService.decreaseUnreadCount(chatRoom.getChatRoomNo(), fromTime, event.kickedUserNo());
+        chatRoomMemberService.leave(member);
+        User kicked = userService.findById(event.kickedUserNo());
+        String displayName = (kicked.getNickname() != null && !kicked.getNickname().isBlank())
+                ? kicked.getNickname() : kicked.getName();
+        String content = displayName + "가 퇴장했습니다.";
+        ChatMessage message = chatMessageService.save(chatRoom, "SYSTEM", content, MessageType.SYSTEM, 0);
+        ChatMessageResponse response = new ChatMessageResponse(
+                message.getMessageNo(), chatRoom.getChatRoomNo(),
+                "SYSTEM", null, content, MessageType.SYSTEM.name(), message.getCreatedAt(), message.getUnreadCount());
+        broadcastSafely(chatRoom, response);
+        notifyUserSafely(event.kickedUserNo(),
+                NotificationMessage.kicked(event.roomNo(), chatRoom.getChatRoomNo()));
     }
 
     private void broadcastSafely(ChatRoom chatRoom, ChatMessageResponse response) {
@@ -69,4 +74,12 @@ private void broadcastSafely(ChatRoom chatRoom, ChatMessageResponse response) {
             log.warn("[Chat] WebSocket 브로드캐스트 실패. chatRoomNo={}", chatRoom.getChatRoomNo(), e);
         }
     }
+
+    private void notifyUserSafely(String userNo, NotificationMessage notification) {
+        try {
+            messagingTemplate.convertAndSendToUser(userNo, "/queue/notification", notification);
+        } catch (Exception e) {
+            log.warn("[Chat] 개인 알림 전송 실패. userNo={}", userNo, e);
+        }
+    }
 }

src/main/java/com/project/dorumdorum/domain/chat/domain/entity/ChatRoom.java

@@ -16,7 +16,8 @@
 @Entity
 @Table(
         indexes = {
-                @Index(name = "idx_chat_room_last_message_at", columnList = "last_message_at")
+                @Index(name = "idx_chat_room_last_message_at", columnList = "last_message_at"),
+                @Index(name = "idx_chat_room_room_no", columnList = "room_no")
         }
 )
 @Getter

src/main/java/com/project/dorumdorum/domain/chat/domain/repository/ChatMessageRepository.java

@@ -10,7 +10,7 @@
 
 public interface ChatMessageRepository extends JpaRepository<ChatMessage, String>, ChatMessageQueryRepository {
 
-    @Modifying(clearAutomatically = true)
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
     @Query("UPDATE ChatMessage m SET m.unreadCount = m.unreadCount - 1 " +
            "WHERE m.chatRoom.chatRoomNo = :chatRoomNo " +
            "AND m.createdAt > :fromTime " +

src/main/java/com/project/dorumdorum/domain/chat/domain/repository/ChatRoomMemberRepository.java

@@ -5,6 +5,7 @@
 import jakarta.persistence.LockModeType;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
@@ -34,4 +35,8 @@ Optional<ChatRoomMember> findByChatRoomNoAndUserNoForUpdate(
     long countByChatRoom(ChatRoom chatRoom);
 
     boolean existsByChatRoom_ChatRoomNoAndUserNo(String chatRoomNo, String userNo);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("DELETE FROM ChatRoomMember m WHERE m.chatRoom = :chatRoom")
+    void deleteAllByChatRoom(@Param("chatRoom") ChatRoom chatRoom);
 }

src/main/java/com/project/dorumdorum/domain/chat/domain/repository/ChatRoomRepository.java

@@ -3,12 +3,17 @@
 import com.project.dorumdorum.domain.chat.domain.entity.ChatRoom;
 import com.project.dorumdorum.domain.chat.domain.entity.ChatRoomType;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface ChatRoomRepository extends JpaRepository<ChatRoom, String>, ChatRoomQueryRepository {
 
     Optional<ChatRoom> findByRoomNoAndChatRoomType(String roomNo, ChatRoomType chatRoomType);
+    List<ChatRoom> findAllByRoomNo(String roomNo);
 
     boolean existsByRoomNo(String roomNo);
 
@@ -17,4 +22,8 @@ boolean existsByRoomNoAndChatRoomTypeAndApplicantUserNo(
 
     Optional<ChatRoom> findByRoomNoAndChatRoomTypeAndApplicantUserNo(
             String roomNo, ChatRoomType chatRoomType, String applicantUserNo);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("DELETE FROM ChatRoom c WHERE c.chatRoomNo = :chatRoomNo")
+    void deleteByChatRoomNo(@Param("chatRoomNo") String chatRoomNo);
 }

src/main/java/com/project/dorumdorum/domain/chat/domain/service/ChatRoomMemberService.java

@@ -9,6 +9,7 @@
 
 import java.time.LocalDateTime;
 import java.util.List;
+import java.util.Optional;
 
 import static com.project.dorumdorum.global.exception.code.status.ChatErrorStatus.*;
 
@@ -34,6 +35,10 @@ public ChatRoomMember findByChatRoomAndUserNo(ChatRoom chatRoom, String userNo)
                 .orElseThrow(() -> new RestApiException(CHAT_ROOM_MEMBER_NOT_FOUND));
     }
 
+    public Optional<ChatRoomMember> findOptionalByChatRoomAndUserNo(ChatRoom chatRoom, String userNo) {
+        return chatRoomMemberRepository.findByChatRoomAndUserNo(chatRoom, userNo);
+    }
+
     public ChatRoomMember findByChatRoomNoAndUserNoForUpdate(String chatRoomNo, String userNo) {
         return chatRoomMemberRepository.findByChatRoomNoAndUserNoForUpdate(chatRoomNo, userNo)
                 .orElseThrow(() -> new RestApiException(CHAT_ROOM_MEMBER_NOT_FOUND));
@@ -65,6 +70,10 @@ public void leave(ChatRoomMember member) {
         chatRoomMemberRepository.delete(member);
     }
 
+    public void deleteAllByChatRoom(ChatRoom chatRoom) {
+        chatRoomMemberRepository.deleteAllByChatRoom(chatRoom);
+    }
+
     public void updateLastReadAt(ChatRoomMember member, LocalDateTime readAt) {
         member.updateLastReadAt(readAt);
         chatRoomMemberRepository.save(member);

src/main/java/com/project/dorumdorum/domain/chat/domain/service/ChatRoomService.java

@@ -67,6 +67,14 @@ public void delete(ChatRoom chatRoom) {
         chatRoomRepository.delete(chatRoom);
     }
 
+    public void deleteByChatRoomNo(String chatRoomNo) {
+        chatRoomRepository.deleteByChatRoomNo(chatRoomNo);
+    }
+
+    public List<ChatRoom> findAllByRoomNo(String roomNo) {
+        return chatRoomRepository.findAllByRoomNo(roomNo);
+    }
+
     public List<ChatRoomSummary> findMyChatRooms(String userNo) {
         return chatRoomRepository.findMyChatRooms(userNo);
     }

src/main/java/com/project/dorumdorum/domain/checklist/domain/repository/RoomRuleRepository.java

@@ -2,6 +2,7 @@
 
 import com.project.dorumdorum.domain.checklist.domain.entity.RoomRule;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
@@ -12,4 +13,7 @@ public interface RoomRuleRepository extends JpaRepository<RoomRule, String> {
     @Query("select rr from RoomRule rr where rr.room.roomNo = :roomNo")
     Optional<RoomRule> findByRoomNo(@Param("roomNo") String roomNo);
 
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("DELETE FROM RoomRule rr WHERE rr.room.roomNo = :roomNo")
+    void deleteByRoomNo(@Param("roomNo") String roomNo);
 }

src/main/java/com/project/dorumdorum/domain/checklist/domain/service/RoomRuleService.java

@@ -24,4 +24,8 @@ public RoomRule findByRoomNo(String roomNo) {
         return roomRuleRepository.findByRoomNo(roomNo)
                 .orElseThrow(() -> new RestApiException(_NOT_FOUND));
     }
+
+    public void deleteByRoomNo(String roomNo) {
+        roomRuleRepository.deleteByRoomNo(roomNo);
+    }
 }

src/main/java/com/project/dorumdorum/domain/room/application/event/RoomDeletedEvent.java

@@ -0,0 +1,10 @@
+package com.project.dorumdorum.domain.room.application.event;
+
+/**
+ * 방 삭제 → 채팅방 삭제 트리거
+ * 발행 책임: DeleteRoomUseCase (room 도메인 담당자)
+ */
+public record RoomDeletedEvent(
+        String roomNo
+) {
+}

src/main/java/com/project/dorumdorum/domain/room/application/usecase/DeleteRoomUseCase.java

@@ -0,0 +1,64 @@
+package com.project.dorumdorum.domain.room.application.usecase;
+
+import com.project.dorumdorum.domain.checklist.domain.service.RoomRuleService;
+import com.project.dorumdorum.domain.room.application.event.RoomDeletedEvent;
+import com.project.dorumdorum.domain.room.domain.entity.Room;
+import com.project.dorumdorum.domain.room.domain.repository.RoomLikeRepository;
+import com.project.dorumdorum.domain.room.domain.service.RoomRequestService;
+import com.project.dorumdorum.domain.room.domain.service.RoomService;
+import com.project.dorumdorum.domain.roommate.domain.service.RoommateService;
+import com.project.dorumdorum.global.exception.RestApiException;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import static com.project.dorumdorum.global.exception.code.status.RoomErrorStatus.CANNOT_DELETE_COMPLETED_ROOM;
+import static com.project.dorumdorum.global.exception.code.status.RoomErrorStatus.NO_PERMISSION_ON_ROOM;
+import static com.project.dorumdorum.global.exception.code.status.RoomErrorStatus.ROOM_HAS_MEMBERS;
+
+@Service
+@Transactional
+@RequiredArgsConstructor
+public class DeleteRoomUseCase {
+
+    private final RoomService roomService;
+    private final RoommateService roommateService;
+    private final RoomRequestService roomRequestService;
+    private final RoomRuleService roomRuleService;
+    private final RoomLikeRepository roomLikeRepository;
+    private final ApplicationEventPublisher eventPublisher;
+
+    /**
+     * 방 삭제
+     * - 방장 권한 검증
+     * - 방장 외 룸메이트 존재 시 삭제 불가
+     * - RoomRequest, RoomLike cascade 삭제 후 방 소프트 삭제
+     * - 채팅방 삭제 이벤트 발행
+     */
+    public void execute(String requesterNo, String roomNo) {
+        Room room = roomService.findByIdForUpdate(roomNo);
+
+        if (!room.isHost(requesterNo)) {
+            throw new RestApiException(NO_PERMISSION_ON_ROOM);
+        }
+
+        if (room.isCompleted()) {
+            throw new RestApiException(CANNOT_DELETE_COMPLETED_ROOM);
+        }
+
+        if (room.getCurrentMateCount() > 1) {
+            throw new RestApiException(ROOM_HAS_MEMBERS);
+        }
+
+        room.delete();
+        roommateService.leaveRoom(requesterNo, roomNo);
+        roomService.flush();
+
+        roomRequestService.deleteAllByRoom(room);
+        roomRuleService.deleteByRoomNo(roomNo);
+        roomLikeRepository.deleteAllByRoom(room);
+
+        eventPublisher.publishEvent(new RoomDeletedEvent(roomNo));
+    }
+}

src/main/java/com/project/dorumdorum/domain/room/application/usecase/KickRoommateUseCase.java

@@ -41,6 +41,7 @@ public void execute(String requesterNo, String roomNo, String kickedUserNo) {
 
         roommateService.leaveRoom(kickedUserNo, roomNo);
         room.minusCurrentMate();
+        roomService.flush();
 
         eventPublisher.publishEvent(new RoommateKickedEvent(roomNo, kickedUserNo));
     }

src/main/java/com/project/dorumdorum/domain/room/domain/repository/RoomLikeRepository.java

@@ -3,11 +3,18 @@
 import com.project.dorumdorum.domain.room.domain.entity.Room;
 import com.project.dorumdorum.domain.room.domain.entity.RoomLike;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 public interface RoomLikeRepository extends JpaRepository<RoomLike, String> {
 
     boolean existsByUserNoAndRoom(String userNo, Room room);
-
     void deleteByUserNoAndRoom(String userNo, Room room);
+
+    // N+1 DELETE 문제 — @Modifying JPQL 벌크 DELETE로 교체
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("DELETE FROM RoomLike l WHERE l.room = :room")
+    void deleteAllByRoom(@Param("room") Room room);
 }