Hotfix: 추방된 유저에게 개인 메세지 전송 (#302)

src/main/java/com/back/domain/studyroom/service/RoomService.java

@@ -719,8 +719,22 @@ public void kickMember(Long roomId, Long targetUserId, Long requesterId) {
 
         // 4. Redis에서 제거 (강제 퇴장) - VISITOR 포함 모든 사용자
         roomParticipantService.exitRoom(targetUserId, roomId);
+
+        // 5. 추방당한 유저에게 개인 WebSocket 메시지 전송
+        java.util.Map<String, Object> kickNotification = new java.util.HashMap<>();
+        kickNotification.put("type", "MEMBER_KICKED");
+        kickNotification.put("roomId", roomId);
+        kickNotification.put("message", "방에서 추방되었습니다");
+
+        messagingTemplate.convertAndSendToUser(
+                targetUserId.toString(),
+                "/queue/kick",
+                kickNotification
+        );
+
+        log.info("추방 알림 전송 완료 - RoomId: {}, TargetUserId: {}", roomId, targetUserId);
 
-        // 5. 멤버 추방 이벤트 발행
+        // 6. 멤버 추방 이벤트 발행 (알림 시스템용)
         Room room = roomRepository.findById(roomId)
                 .orElseThrow(() -> new CustomException(ErrorCode.ROOM_NOT_FOUND));
 

src/test/java/com/back/domain/studyroom/service/RoomServiceTest.java

@@ -64,6 +64,9 @@ class RoomServiceTest {
 
     @Mock
     private RoomThumbnailService roomThumbnailService;
+
+    @Mock
+    private org.springframework.messaging.simp.SimpMessagingTemplate messagingTemplate;
 
     @InjectMocks
     private RoomService roomService;
@@ -400,13 +403,15 @@ void kickMember_Success() {
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 1L)).willReturn(Optional.of(hostMember));
         given(roomParticipantService.getParticipants(1L)).willReturn(java.util.Set.of(2L)); // 온라인 사용자 목록
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 2L)).willReturn(Optional.empty()); // VISITOR는 DB에 없음
-        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom));
+        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom)); // Room 조회 추가
 
         // when
         roomService.kickMember(1L, 2L, 1L);
 
         // then
         verify(roomParticipantService, times(1)).exitRoom(2L, 1L); // Redis 퇴장 확인
+        verify(messagingTemplate, times(1)).convertAndSendToUser(eq("2"), eq("/queue/kick"), any()); // WebSocket 메시지 전송 확인
+        verify(eventPublisher, times(1)).publishEvent(any(com.back.domain.notification.event.studyroom.MemberKickedEvent.class)); // 이벤트 발행 확인
     }
 
     @Test
@@ -418,13 +423,15 @@ void kickMember_VisitorSuccess() {
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 1L)).willReturn(Optional.of(hostMember));
         given(roomParticipantService.getParticipants(1L)).willReturn(java.util.Set.of(2L)); // VISITOR가 온라인 상태
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 2L)).willReturn(Optional.empty()); // DB에 없음
-        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom));
+        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom)); // Room 조회 추가
 
         // when
         roomService.kickMember(1L, 2L, 1L);
 
         // then
         verify(roomParticipantService, times(1)).exitRoom(2L, 1L);
+        verify(messagingTemplate, times(1)).convertAndSendToUser(eq("2"), eq("/queue/kick"), any()); // WebSocket 메시지 전송 확인
+        verify(eventPublisher, times(1)).publishEvent(any(com.back.domain.notification.event.studyroom.MemberKickedEvent.class)); // 이벤트 발행 확인
     }
 
     @Test
@@ -448,13 +455,15 @@ void kickMember_MemberSuccess() {
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 1L)).willReturn(Optional.of(hostMember));
         given(roomParticipantService.getParticipants(1L)).willReturn(java.util.Set.of(2L)); // MEMBER가 온라인 상태
         given(roomMemberRepository.findByRoomIdAndUserId(1L, 2L)).willReturn(Optional.of(targetMember)); // DB에 있음
-        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom));
+        given(roomRepository.findById(1L)).willReturn(Optional.of(testRoom)); // Room 조회 추가
 
         // when
         roomService.kickMember(1L, 2L, 1L);
 
         // then
         verify(roomParticipantService, times(1)).exitRoom(2L, 1L);
+        verify(messagingTemplate, times(1)).convertAndSendToUser(eq("2"), eq("/queue/kick"), any()); // WebSocket 메시지 전송 확인
+        verify(eventPublisher, times(1)).publishEvent(any(com.back.domain.notification.event.studyroom.MemberKickedEvent.class)); // 이벤트 발행 확인
     }
 
     @Test