feat: 실시간 인앱 채팅 (STOMP over WebSocket)

- 스팟별 채팅방(/topic/spots/{id}), 전송 /app/spots/{id}/chat, 엔드포인트 /ws
- STOMP CONNECT Bearer 토큰 인증(ChannelInterceptor) → 미인증 전송 무시
- ChatRoom/ChatMessage 도메인, 방 없으면 최초 메시지 시 생성, 발신자 닉네임 포함
- GET /api/chat/spots/{id}/messages 히스토리(보호), 전역 WebSocket 브로커(인메모리)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/main/java/com/dog/dognation/api/ChatController.java

@@ -0,0 +1,27 @@
+package com.dog.dognation.api;
+
+import com.dog.dognation.api.dto.ChatDtos.ChatMessageResponse;
+import com.dog.dognation.domain.chat.ChatService;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+/** 스팟 채팅 히스토리 (로그인 필요). 실시간 송수신은 WebSocket(/ws). */
+@RestController
+@RequestMapping("/api/chat")
+public class ChatController {
+
+    private final ChatService chatService;
+
+    public ChatController(ChatService chatService) {
+        this.chatService = chatService;
+    }
+
+    @GetMapping("/spots/{spotId}/messages")
+    public List<ChatMessageResponse> history(@PathVariable Long spotId) {
+        return chatService.history(spotId);
+    }
+}

src/main/java/com/dog/dognation/api/dto/ChatDtos.java

@@ -0,0 +1,28 @@
+package com.dog.dognation.api.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+import java.time.OffsetDateTime;
+
+public final class ChatDtos {
+
+    private ChatDtos() {
+    }
+
+    public record ChatMessageResponse(
+            Long id,
+            Long spotId,
+            Long senderId,
+            String senderNickname,
+            String content,
+            OffsetDateTime createdAt) {
+    }
+
+    /** WebSocket 전송 페이로드. */
+    public record ChatSendRequest(
+            @NotBlank(message = "내용이 비어있습니다.")
+            @Size(max = 1000, message = "메시지는 1000자 이하여야 합니다.")
+            String content) {
+    }
+}

src/main/java/com/dog/dognation/chat/ChatSocketController.java

@@ -0,0 +1,42 @@
+package com.dog.dognation.chat;
+
+import com.dog.dognation.api.dto.ChatDtos.ChatMessageResponse;
+import com.dog.dognation.api.dto.ChatDtos.ChatSendRequest;
+import com.dog.dognation.domain.chat.ChatService;
+import jakarta.validation.Valid;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.messaging.handler.annotation.DestinationVariable;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.stereotype.Controller;
+
+import java.security.Principal;
+
+/** 스팟 채팅 메시지 수신 → 저장 → 구독자에게 브로드캐스트. */
+@Controller
+public class ChatSocketController {
+
+    private static final Logger log = LoggerFactory.getLogger(ChatSocketController.class);
+
+    private final ChatService chatService;
+    private final SimpMessagingTemplate messagingTemplate;
+
+    public ChatSocketController(ChatService chatService, SimpMessagingTemplate messagingTemplate) {
+        this.chatService = chatService;
+        this.messagingTemplate = messagingTemplate;
+    }
+
+    @MessageMapping("/spots/{spotId}/chat")
+    public void send(@DestinationVariable Long spotId,
+                     @Valid @Payload ChatSendRequest req,
+                     Principal principal) {
+        if (!(principal instanceof StompPrincipal user)) {
+            log.warn("[chat] 미인증 전송 시도 spot={}", spotId);
+            return; // 인증되지 않은 연결은 무시
+        }
+        ChatMessageResponse res = chatService.post(spotId, user.userId(), req.content());
+        messagingTemplate.convertAndSend("/topic/spots/" + spotId, res);
+    }
+}

src/main/java/com/dog/dognation/chat/StompAuthChannelInterceptor.java

@@ -0,0 +1,40 @@
+package com.dog.dognation.chat;
+
+import com.dog.dognation.auth.AuthService;
+import com.dog.dognation.auth.SessionUser;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.simp.stomp.StompCommand;
+import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
+import org.springframework.messaging.support.ChannelInterceptor;
+import org.springframework.messaging.support.MessageHeaderAccessor;
+import org.springframework.stereotype.Component;
+
+/**
+ * STOMP CONNECT 시 Authorization: Bearer 토큰을 검증해 인증 주체를 세션에 심는다.
+ * 이후 SEND 프레임에서 Principal 로 발신자를 식별한다.
+ */
+@Component
+public class StompAuthChannelInterceptor implements ChannelInterceptor {
+
+    private final AuthService authService;
+
+    public StompAuthChannelInterceptor(AuthService authService) {
+        this.authService = authService;
+    }
+
+    @Override
+    public Message<?> preSend(Message<?> message, MessageChannel channel) {
+        StompHeaderAccessor accessor =
+                MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
+        if (accessor != null && StompCommand.CONNECT.equals(accessor.getCommand())) {
+            String bearer = accessor.getFirstNativeHeader("Authorization");
+            String token = (bearer != null && bearer.startsWith("Bearer ")) ? bearer.substring(7) : null;
+            SessionUser user = authService.getSession(token);
+            if (user != null) {
+                accessor.setUser(new StompPrincipal(String.valueOf(user.id()), user.role()));
+            }
+        }
+        return message;
+    }
+}

src/main/java/com/dog/dognation/chat/StompPrincipal.java

@@ -0,0 +1,16 @@
+package com.dog.dognation.chat;
+
+import java.security.Principal;
+
+/** WebSocket 세션의 인증 주체. name 에 userId 문자열을 담는다. */
+public record StompPrincipal(String name, String role) implements Principal {
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    public Long userId() {
+        return Long.valueOf(name);
+    }
+}

src/main/java/com/dog/dognation/chat/WebSocketConfig.java

@@ -0,0 +1,44 @@
+package com.dog.dognation.chat;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.simp.config.ChannelRegistration;
+import org.springframework.messaging.simp.config.MessageBrokerRegistry;
+import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
+import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
+import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
+
+/**
+ * STOMP over WebSocket 설정.
+ *   엔드포인트 : /ws
+ *   구독       : /topic/spots/{spotId}
+ *   전송       : /app/spots/{spotId}/chat
+ */
+@Configuration
+@EnableWebSocketMessageBroker
+public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
+
+    private final StompAuthChannelInterceptor authChannelInterceptor;
+
+    public WebSocketConfig(StompAuthChannelInterceptor authChannelInterceptor) {
+        this.authChannelInterceptor = authChannelInterceptor;
+    }
+
+    @Override
+    public void registerStompEndpoints(StompEndpointRegistry registry) {
+        registry.addEndpoint("/ws")
+                .setAllowedOriginPatterns(
+                        "http://localhost:9000", "http://localhost",
+                        "capacitor://localhost", "ionic://localhost");
+    }
+
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry registry) {
+        registry.enableSimpleBroker("/topic");           // 인메모리 브로커
+        registry.setApplicationDestinationPrefixes("/app");
+    }
+
+    @Override
+    public void configureClientInboundChannel(ChannelRegistration registration) {
+        registration.interceptors(authChannelInterceptor); // CONNECT 인증
+    }
+}

src/main/java/com/dog/dognation/config/WebConfig.java

@@ -40,7 +40,8 @@ public class WebConfig implements WebMvcConfigurer {
     public void addInterceptors(InterceptorRegistry registry) {
         // 인증: 로그인 필요한 경로 (관리자 경로 포함 — SessionUser 세팅용으로 먼저 실행)
         registry.addInterceptor(authInterceptor)
-                .addPathPatterns("/api/auth/me", "/api/auth/logout", "/api/admin/**", "/api/dogs/**");
+                .addPathPatterns("/api/auth/me", "/api/auth/logout", "/api/admin/**",
+                        "/api/dogs/**", "/api/chat/**");
         // 인가: 관리자 전용 (authInterceptor 다음에 실행되어 role 검사)
         registry.addInterceptor(adminInterceptor)
                 .addPathPatterns("/api/admin/**");

src/main/java/com/dog/dognation/domain/chat/ChatMessage.java

@@ -0,0 +1,57 @@
+package com.dog.dognation.domain.chat;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import java.time.OffsetDateTime;
+
+@Entity
+@Table(name = "chat_messages")
+public class ChatMessage {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "room_id", nullable = false)
+    private Long roomId;
+
+    @Column(name = "sender_id", nullable = false)
+    private Long senderId;
+
+    @Column(nullable = false, length = 1000)
+    private String content;
+
+    @Column(name = "created_at", nullable = false)
+    private OffsetDateTime createdAt = OffsetDateTime.now();
+
+    protected ChatMessage() {
+    }
+
+    public ChatMessage(Long roomId, Long senderId, String content) {
+        this.roomId = roomId;
+        this.senderId = senderId;
+        this.content = content;
+        this.createdAt = OffsetDateTime.now();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public Long getSenderId() {
+        return senderId;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public OffsetDateTime getCreatedAt() {
+        return createdAt;
+    }
+}

src/main/java/com/dog/dognation/domain/chat/ChatMessageRepository.java

@@ -0,0 +1,11 @@
+package com.dog.dognation.domain.chat;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface ChatMessageRepository extends JpaRepository<ChatMessage, Long> {
+
+    /** 방의 최근 메시지(오름차순). MVP: 최근 100건. */
+    List<ChatMessage> findTop100ByRoomIdOrderByCreatedAtAsc(Long roomId);
+}

src/main/java/com/dog/dognation/domain/chat/ChatRoom.java

@@ -0,0 +1,42 @@
+package com.dog.dognation.domain.chat;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import java.time.OffsetDateTime;
+
+/** 스팟 기반 오픈 채팅방. 스팟당 1개, 최초 메시지 시 생성. */
+@Entity
+@Table(name = "chat_rooms")
+public class ChatRoom {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "spot_id")
+    private Long spotId;
+
+    @Column(name = "created_at", nullable = false)
+    private OffsetDateTime createdAt = OffsetDateTime.now();
+
+    protected ChatRoom() {
+    }
+
+    public ChatRoom(Long spotId) {
+        this.spotId = spotId;
+        this.createdAt = OffsetDateTime.now();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public Long getSpotId() {
+        return spotId;
+    }
+}

src/main/java/com/dog/dognation/domain/chat/ChatRoomRepository.java

@@ -0,0 +1,10 @@
+package com.dog.dognation.domain.chat;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface ChatRoomRepository extends JpaRepository<ChatRoom, Long> {
+
+    Optional<ChatRoom> findBySpotId(Long spotId);
+}

src/main/java/com/dog/dognation/domain/chat/ChatService.java

@@ -0,0 +1,76 @@
+package com.dog.dognation.domain.chat;
+
+import com.dog.dognation.api.dto.ChatDtos.ChatMessageResponse;
+import com.dog.dognation.common.exception.ApiException;
+import com.dog.dognation.domain.spot.SpotRepository;
+import com.dog.dognation.domain.user.User;
+import com.dog.dognation.domain.user.UserRepository;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@Service
+public class ChatService {
+
+    private final ChatRoomRepository roomRepository;
+    private final ChatMessageRepository messageRepository;
+    private final SpotRepository spotRepository;
+    private final UserRepository userRepository;
+
+    public ChatService(ChatRoomRepository roomRepository,
+                       ChatMessageRepository messageRepository,
+                       SpotRepository spotRepository,
+                       UserRepository userRepository) {
+        this.roomRepository = roomRepository;
+        this.messageRepository = messageRepository;
+        this.spotRepository = spotRepository;
+        this.userRepository = userRepository;
+    }
+
+    /** 스팟 채팅방 확보(없으면 생성). */
+    @Transactional
+    public ChatRoom roomForSpot(Long spotId) {
+        if (!spotRepository.existsById(spotId)) {
+            throw new ApiException(HttpStatus.NOT_FOUND, "스팟을 찾을 수 없습니다.");
+        }
+        return roomRepository.findBySpotId(spotId)
+                .orElseGet(() -> roomRepository.save(new ChatRoom(spotId)));
+    }
+
+    /** 스팟 채팅 최근 메시지. 방이 없으면 빈 목록. */
+    @Transactional(readOnly = true)
+    public List<ChatMessageResponse> history(Long spotId) {
+        return roomRepository.findBySpotId(spotId)
+                .map(room -> toResponses(spotId, messageRepository.findTop100ByRoomIdOrderByCreatedAtAsc(room.getId())))
+                .orElseGet(List::of);
+    }
+
+    /** 메시지 저장 후 브로드캐스트용 응답 반환. */
+    @Transactional
+    public ChatMessageResponse post(Long spotId, Long senderId, String content) {
+        ChatRoom room = roomForSpot(spotId);
+        ChatMessage saved = messageRepository.save(new ChatMessage(room.getId(), senderId, content));
+        String nickname = userRepository.findById(senderId).map(User::getNickname).orElse("알 수 없음");
+        return new ChatMessageResponse(saved.getId(), spotId, senderId, nickname,
+                saved.getContent(), saved.getCreatedAt());
+    }
+
+    private List<ChatMessageResponse> toResponses(Long spotId, List<ChatMessage> messages) {
+        if (messages.isEmpty()) {
+            return List.of();
+        }
+        List<Long> senderIds = messages.stream().map(ChatMessage::getSenderId).distinct().toList();
+        Map<Long, String> nicknames = userRepository.findAllById(senderIds).stream()
+                .collect(Collectors.toMap(User::getId, User::getNickname, (a, b) -> a));
+        return messages.stream()
+                .map(m -> new ChatMessageResponse(m.getId(), spotId, m.getSenderId(),
+                        nicknames.getOrDefault(m.getSenderId(), "알 수 없음"),
+                        m.getContent(), m.getCreatedAt()))
+                .collect(Collectors.toList());
+    }
+}