[Feat/#91] 채팅 기능 구현

build.gradle

@@ -56,8 +56,13 @@ dependencies {
 	//prometheus
 	implementation 'org.springframework.boot:spring-boot-starter-actuator'
 	implementation 'io.micrometer:micrometer-registry-prometheus'
+
+	// websocket + stomp
+	implementation 'org.springframework.boot:spring-boot-starter-websocket'
+
 }
 
+
 tasks.named('test') {
 	useJUnitPlatform()
 }

src/main/java/B1G4/bookmark/config/WebSocketConfig.java

@@ -0,0 +1,27 @@
+package B1G4.bookmark.config;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+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;
+
+@Configuration
+@RequiredArgsConstructor
+@EnableWebSocketMessageBroker
+public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
+
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry config) {
+        config.enableSimpleBroker("/topic"); // 구독 경로
+        config.setApplicationDestinationPrefixes("/app"); // 클라이언트 발행 경로
+    }
+
+    @Override
+    public void registerStompEndpoints(StompEndpointRegistry registry) {
+        registry.addEndpoint("/ws") // WebSocket 엔드포인트
+                .setAllowedOriginPatterns("*") // 모든 Origin 허용
+                .withSockJS(); // SockJS Fallback 지원
+    }
+}

src/main/java/B1G4/bookmark/domain/ChatRoom.java

@@ -0,0 +1,18 @@
+package B1G4.bookmark.domain;
+
+import jakarta.persistence.*;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Entity
+public class ChatRoom {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    private String name;
+}

src/main/java/B1G4/bookmark/repository/ChatRoomRepository.java

@@ -0,0 +1,7 @@
+package B1G4.bookmark.repository;
+
+import B1G4.bookmark.domain.ChatRoom;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ChatRoomRepository extends JpaRepository<ChatRoom, Long> {
+}

src/main/java/B1G4/bookmark/service/ChatRoomService/ChatRoomService.java

@@ -0,0 +1,4 @@
+package B1G4.bookmark.service.ChatRoomService;
+
+public interface ChatRoomService {
+}

src/main/java/B1G4/bookmark/service/ChatRoomService/ChatRoomServiceImpl.java

@@ -0,0 +1,48 @@
+package B1G4.bookmark.service.ChatRoomService;
+
+import B1G4.bookmark.domain.Member;
+import B1G4.bookmark.repository.ChatRoomRepository;
+import B1G4.bookmark.repository.MemberRepository;
+import B1G4.bookmark.web.dto.ChatMessageDTO.ChatMessageDTO;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+
+@Service
+@RequiredArgsConstructor
+public class ChatRoomServiceImpl {
+
+
+    private final ChatRoomRepository chatRoomRepository;
+    private final MemberRepository memberRepository;
+
+    // 채팅방 입장 처리
+    public ChatMessageDTO handleJoinChatRoom(Long chatRoomId, Long senderId) {
+        // 채팅방 유효성 확인
+        chatRoomRepository.findById(chatRoomId)
+                .orElseThrow(() -> new IllegalArgumentException("ChatRoom not found"));
+
+        // 사용자 확인 및 닉네임 설정
+        Member member = memberRepository.findById(senderId)
+                .orElseThrow(() -> new IllegalArgumentException("Member not found"));
+
+        String nickname = member.getNickname();
+        String message = nickname + " 님이 입장했습니다.";
+        LocalDateTime timestamp = LocalDateTime.now();
+
+        return new ChatMessageDTO(nickname, message, timestamp);
+    }
+
+    // 메시지 전송 처리
+    public ChatMessageDTO handleSendMessage(Long chatRoomId, ChatMessageDTO messageDTO) {
+        // 채팅방 유효성 확인
+        chatRoomRepository.findById(chatRoomId)
+                .orElseThrow(() -> new IllegalArgumentException("ChatRoom not found"));
+
+        // 메시지에 타임스탬프 추가
+        messageDTO.setTimestamp(LocalDateTime.now());
+
+        return messageDTO;
+    }
+}

src/main/java/B1G4/bookmark/web/controller/ChatController.java

@@ -0,0 +1,70 @@
+package B1G4.bookmark.web.controller;
+
+
+import B1G4.bookmark.domain.Member;
+import B1G4.bookmark.security.handler.annotation.AuthUser;
+import B1G4.bookmark.service.ChatRoomService.ChatRoomServiceImpl;
+import B1G4.bookmark.web.dto.ChatMessageDTO.ChatMessageDTO;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import lombok.RequiredArgsConstructor;
+import org.springframework.messaging.handler.annotation.DestinationVariable;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.handler.annotation.SendTo;
+import org.springframework.stereotype.Controller;
+
+@Controller
+@RequiredArgsConstructor
+public class ChatController {
+
+    private final ChatRoomServiceImpl chatRoomService;
+
+    // 채팅방 입장
+    /**
+     * 채팅방 입장
+     * 클라이언트는 /app/chat/{chatRoomId}/join으로 메시지를 발행합니다.
+     * 서버는 /topic/chat/{chatRoomId}로 구독 중인 모든 클라이언트에게 메시지를 브로드캐스트합니다.
+     */
+    @Operation(
+            summary = "채팅방 입장",
+            description = "사용자가 특정 채팅방에 입장합니다. 입장 메시지는 구독 중인 모든 사용자에게 전송됩니다."
+    )
+    @MessageMapping("/chat/{chatRoomId}/join")
+    @SendTo("/topic/chat/{chatRoomId}")
+    public ChatMessageDTO joinChatRoom(
+            @DestinationVariable @Parameter(
+                    description = "입장할 채팅방의 ID",
+                    required = true,
+                    example = "1"
+            ) Long chatRoomId,
+            @Parameter(name = "user", hidden = true)
+            @AuthUser Member member) {
+        return chatRoomService.handleJoinChatRoom(chatRoomId, member.getId());
+    }
+
+    // 메시지 전송
+    /**
+     * 메시지 전송
+     * 클라이언트는 /app/chat/{chatRoomId}/send로 메시지를 발행합니다.
+     * 서버는 /topic/chat/{chatRoomId}로 구독 중인 모든 클라이언트에게 메시지를 브로드캐스트합니다.
+     */
+    @Operation(
+            summary = "메시지 전송",
+            description = "사용자가 특정 채팅방에 메시지를 전송합니다. 메시지는 구독 중인 모든 사용자에게 브로드캐스트됩니다."
+    )
+    @MessageMapping("/chat/{chatRoomId}/send")
+    @SendTo("/topic/chat/{chatRoomId}")
+    public ChatMessageDTO sendMessage(
+            @DestinationVariable @Parameter(
+                    description = "메시지를 전송할 채팅방의 ID",
+                    required = true,
+                    example = "1"
+            ) Long chatRoomId,
+            @Parameter(
+                    description = "전송할 메시지의 정보 (메시지만 포함)",
+                    required = true
+            )
+            ChatMessageDTO messageDTO) {
+        return chatRoomService.handleSendMessage(chatRoomId, messageDTO);
+    }
+}

src/main/java/B1G4/bookmark/web/dto/ChatMessageDTO/ChatMessageDTO.java

@@ -0,0 +1,18 @@
+package B1G4.bookmark.web.dto.ChatMessageDTO;
+
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import lombok.*;
+
+import java.time.LocalDateTime;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+public class ChatMessageDTO {
+    private String nickname;          // 보낸 사용자 닉네임
+    private String message;           // 메시지 내용
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm")
+    private LocalDateTime timestamp;  // 메시지 타임스탬프
+}