채팅 메세지 송/수신 API 구현

build.gradle

@@ -26,6 +26,9 @@ dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-validation'
 	implementation 'org.springframework.boot:spring-boot-starter-web'
 	implementation 'org.springframework.boot:spring-boot-starter-security'
+	implementation 'org.springframework.boot:spring-boot-starter-websocket'
+	implementation 'org.webjars:stomp-websocket:2.3.3-1'
+	implementation 'org.webjars:sockjs-client:1.1.2'
 	runtimeOnly 'com.h2database:h2'
 	runtimeOnly 'com.mysql:mysql-connector-j'
 	compileOnly 'org.projectlombok:lombok'

src/main/java/kr/co/fastcampus/yanabada/common/config/WebSockConfig.java

@@ -0,0 +1,23 @@
+package kr.co.fastcampus.yanabada.common.config;
+
+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
+@EnableWebSocketMessageBroker
+public class WebSockConfig implements WebSocketMessageBrokerConfigurer {
+
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry config) {
+        config.enableSimpleBroker("/sub");
+        config.setApplicationDestinationPrefixes("/pub");
+    }
+
+    @Override
+    public void registerStompEndpoints(StompEndpointRegistry registry) {
+        registry.addEndpoint("/ws-stomp").setAllowedOrigins("*").withSockJS();
+    }
+}

src/main/java/kr/co/fastcampus/yanabada/domain/chat/controller/ChatController.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import kr.co.fastcampus.yanabada.common.response.ResponseBody;
+import kr.co.fastcampus.yanabada.domain.chat.dto.ReceivedChatMessage;
 import kr.co.fastcampus.yanabada.domain.chat.dto.request.ChatRoomModifyRequest;
 import kr.co.fastcampus.yanabada.domain.chat.dto.request.ChatRoomSaveRequest;
 import kr.co.fastcampus.yanabada.domain.chat.dto.response.ChatMessageInfoResponse;
@@ -10,6 +11,8 @@
 import kr.co.fastcampus.yanabada.domain.chat.dto.response.ChatRoomSummaryResponse;
 import kr.co.fastcampus.yanabada.domain.chat.service.ChatService;
 import lombok.RequiredArgsConstructor;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -26,6 +29,15 @@ public class ChatController {
 
     private final ChatService chatService;
 
+    private final SimpMessagingTemplate messagingTemplate;
+
+    @MessageMapping("/message")
+    public void message(ReceivedChatMessage message) {
+        messagingTemplate.convertAndSend(
+            "/sub/chatroom/" + message.chatRoomCode(), chatService.saveChatMessage(message)
+        );
+    }
+
     @PostMapping
     public ResponseBody<ChatRoomInfoResponse> getOrAddChatRoom(
         @RequestBody ChatRoomSaveRequest request
@@ -35,7 +47,6 @@ public ResponseBody<ChatRoomInfoResponse> getOrAddChatRoom(
 
     @GetMapping
     public ResponseBody<List<ChatRoomSummaryResponse>> getChatRooms(
-    //Principal 을 통해 로그인한 멤버 id를 가져올 예정
     ) {
         Long memberId = 1L;
         return ResponseBody.ok(chatService.getChatRooms(memberId));

src/main/java/kr/co/fastcampus/yanabada/domain/chat/dto/ReceivedChatMessage.java

@@ -0,0 +1,37 @@
+package kr.co.fastcampus.yanabada.domain.chat.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
+import jakarta.validation.constraints.Positive;
+import jakarta.validation.constraints.Size;
+import java.time.LocalDateTime;
+import kr.co.fastcampus.yanabada.domain.chat.entity.ChatMessage;
+import kr.co.fastcampus.yanabada.domain.chat.entity.ChatRoom;
+import kr.co.fastcampus.yanabada.domain.member.entity.Member;
+
+public record ReceivedChatMessage(
+    @Size(min = 18, max = 18, message = "유효하지 않은 채팅방 코드입니다.")
+    @Pattern(regexp = "^[0-9a-f]+$", message = "유효하지 않은 채팅방 코드입니다.")
+    String chatRoomCode,
+    @NotNull(message = "전송자 ID는 필수로 입력하셔야 합니다.")
+    @Positive(message = "전송자 ID는 양수이어야 합니다.")
+    Long sendId,
+    @NotBlank(message = "메세지 내용이 없습니다.")
+    @Size(max = 255, message = "메세지 내용은 255자를 넘을 수 없습니다.")
+    String content
+) {
+
+    public ChatMessage toEntity(
+        ChatRoom chatRoom,
+        Member sender,
+        LocalDateTime sendDateTime
+    ) {
+        return ChatMessage.create(
+            chatRoom,
+            sender,
+            content,
+            sendDateTime
+        );
+    }
+}

src/main/java/kr/co/fastcampus/yanabada/domain/chat/dto/SendChatMessage.java

@@ -0,0 +1,35 @@
+package kr.co.fastcampus.yanabada.domain.chat.dto;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import java.time.LocalDateTime;
+import kr.co.fastcampus.yanabada.domain.chat.entity.ChatRoom;
+import kr.co.fastcampus.yanabada.domain.member.entity.Member;
+import lombok.Builder;
+
+@Builder
+public record SendChatMessage(
+    String chatRoomCode,
+    Long sendId,
+    String senderNickname,
+    String senderProfileImage,
+    String content,
+    @JsonFormat(pattern = "yyyy-MM-dd HH:mm")
+    LocalDateTime sendTime
+) {
+
+    public static SendChatMessage from(
+        ChatRoom chatRoom,
+        Member sender,
+        String content,
+        LocalDateTime sendTime
+    ) {
+        return SendChatMessage.builder()
+            .chatRoomCode(chatRoom.getCode())
+            .sendId(sender.getId())
+            .senderNickname(sender.getNickName())
+            .senderProfileImage(sender.getImageUrl())
+            .content(content)
+            .sendTime(sendTime)
+            .build();
+    }
+}

src/main/java/kr/co/fastcampus/yanabada/domain/chat/dto/response/ChatMessageInfoResponse.java

@@ -14,7 +14,7 @@ public record ChatMessageInfoResponse(
     LocalDateTime sendDateTime
 ) {
 
-    public static ChatMessageInfoResponse create(
+    public static ChatMessageInfoResponse from(
         Member sender, String content, LocalDateTime sendDateTime
     ) {
         return ChatMessageInfoResponse.builder()

src/main/java/kr/co/fastcampus/yanabada/domain/chat/dto/response/ChatRoomModifyResponse.java

@@ -8,7 +8,7 @@ public record ChatRoomModifyResponse(
     Long updatedMemberId
 ) {
 
-    public static ChatRoomModifyResponse create(String chatRoomCode, Long updatedMemberId) {
+    public static ChatRoomModifyResponse from(String chatRoomCode, Long updatedMemberId) {
         return ChatRoomModifyResponse.builder()
             .chatRoomCode(chatRoomCode)
             .updatedMemberId(updatedMemberId)

src/main/java/kr/co/fastcampus/yanabada/domain/chat/dto/response/ChatRoomSummaryResponse.java

@@ -20,7 +20,7 @@ public record ChatRoomSummaryResponse(
     Integer unreadMessageCount
 ) {
 
-    public static ChatRoomSummaryResponse create(
+    public static ChatRoomSummaryResponse from(
         String chatRoomCode,
         Member partner,
         ChatMessage message,

src/main/java/kr/co/fastcampus/yanabada/domain/chat/service/ChatService.java

@@ -4,9 +4,12 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+
 import kr.co.fastcampus.yanabada.common.exception.CannotNegotiateOwnProductException;
 import kr.co.fastcampus.yanabada.common.exception.IncorrectChatRoomMember;
 import kr.co.fastcampus.yanabada.common.exception.NegotiationNotPossibleException;
+import kr.co.fastcampus.yanabada.domain.chat.dto.ReceivedChatMessage;
+import kr.co.fastcampus.yanabada.domain.chat.dto.SendChatMessage;
 import kr.co.fastcampus.yanabada.domain.chat.dto.request.ChatRoomModifyRequest;
 import kr.co.fastcampus.yanabada.domain.chat.dto.request.ChatRoomSaveRequest;
 import kr.co.fastcampus.yanabada.domain.chat.dto.response.ChatMessageInfoResponse;
@@ -113,7 +116,7 @@ private ChatRoomSummaryResponse createChatRoomSummaryResponse(
         List<ChatMessage> messages,
         int unreadCount
     ) {
-        return ChatRoomSummaryResponse.create(
+        return ChatRoomSummaryResponse.from(
             chatRoom.getCode(),
             partner,
             messages.get(messages.size() - 1),
@@ -153,7 +156,7 @@ public List<ChatMessageInfoResponse> getChatRoomMessages(Long memberId, String c
         Member member = memberRepository.getMember(memberId);
         checkChatRoomMember(chatRoom, member);
         return chatRoom.getMessages().stream()
-            .map(message -> ChatMessageInfoResponse.create(
+            .map(message -> ChatMessageInfoResponse.from(
                 message.getSender(), message.getContent(), message.getSendDateTime()
             ))
             .toList();
@@ -170,7 +173,7 @@ public ChatRoomModifyResponse updateChatRoom(Long memberId, ChatRoomModifyReques
         ChatRoom chatRoom = chatRoomRepository.getChatroom(request.chatRoomCode());
         Member member = memberRepository.getMember(memberId);
         updateLastCheckTime(chatRoom, member);
-        return ChatRoomModifyResponse.create(chatRoom.getCode(), memberId);
+        return ChatRoomModifyResponse.from(chatRoom.getCode(), memberId);
     }
 
     private void updateLastCheckTime(ChatRoom chatRoom, Member member) {
@@ -196,13 +199,17 @@ public ChatRoomModifyResponse modifyOrDeleteChatRoom(
         } else {
             handleBuyerAction(chatRoom);
         }
-        return ChatRoomModifyResponse.create(chatRoom.getCode(), memberId);
+        return ChatRoomModifyResponse.from(chatRoom.getCode(), memberId);
     }
 
     private boolean isSeller(Member member, ChatRoom chatRoom) {
         return member.equals(chatRoom.getSeller());
     }
 
+    private boolean isBuyer(Member member, ChatRoom chatRoom) {
+        return member.equals(chatRoom.getBuyer());
+    }
+
     private void handleSellerAction(ChatRoom chatRoom) {
         if (chatRoom.getHasBuyerLeft()) {
             chatRoomRepository.delete(chatRoom);
@@ -218,4 +225,35 @@ private void handleBuyerAction(ChatRoom chatRoom) {
             chatRoom.updateHasBuyerLeft(true);
         }
     }
+
+    @Transactional
+    public SendChatMessage saveChatMessage(ReceivedChatMessage message) {
+        ChatRoom chatRoom = chatRoomRepository.getChatroom(message.chatRoomCode());
+        Member sender = memberRepository.getMember(message.sendId());
+        LocalDateTime sendTime = LocalDateTime.now();
+        checkChatRoomMember(chatRoom, sender);
+        updateMemberPresenceStatus(chatRoom, sender);
+        addMessageToChatRoom(chatRoom, message, sender, sendTime);
+        return createSendChatMessage(chatRoom, sender, message, sendTime);
+    }
+
+    private void addMessageToChatRoom(
+        ChatRoom chatRoom, ReceivedChatMessage message, Member sender, LocalDateTime sendTime
+    ) {
+        chatRoom.addChatMessage(message.toEntity(chatRoom, sender, sendTime));
+    }
+
+    private void updateMemberPresenceStatus(ChatRoom chatRoom, Member sender) {
+        if (isSeller(sender, chatRoom) && chatRoom.getHasSellerLeft()) {
+            chatRoom.updateHasSellerLeft(false);
+        } else if (isBuyer(sender, chatRoom) && chatRoom.getHasBuyerLeft()) {
+            chatRoom.updateHasBuyerLeft(false);
+        }
+    }
+
+    private SendChatMessage createSendChatMessage(
+        ChatRoom chatRoom, Member sender, ReceivedChatMessage message, LocalDateTime sendTime
+    ) {
+        return SendChatMessage.from(chatRoom, sender, message.content(), sendTime);
+    }
 }