style : 채팅 코드 예외 처리 및 코드 리팩토링

src/main/java/com/teamjo/techeermarket/domain/chats/controller/ChatController.java

@@ -14,19 +14,11 @@
 
 @Controller
 @RequiredArgsConstructor
-//@RequestMapping("/api/chat") - ws에서 지원 x
 public class ChatController {
 
   private final SimpMessageSendingOperations template;
   private final ChatService chatService;
 
-//  // 처음 시작하는 체팅 -> 채팅방 제작
-//  // 기존에 존재하는 채팅 -> 채팅방 id 반환만
-//  @MessageMapping("/api/chat/enterRoom")
-//  public void enterUser(@Payload ChatReq chat) {
-//
-//  }
-
   @MessageMapping("/api/chat/sendMessage")
   public void sendMessage(@Payload ChatReq chat) {
     chatService.saveMessage(chat);

src/main/java/com/teamjo/techeermarket/domain/chats/controller/ChatRoomController.java

@@ -41,8 +41,6 @@ public ResponseEntity<ChatCreateRes> createRoom(
     return ResponseEntity.status(HttpStatus.CREATED).body(chatCreateRes);
   }
 
-
-
   /*
    * @Describe : 채팅방 리스트 조회
    * @Param1 : userDetailsImpl(UserDetailsImpl) 로그인 유저

src/main/java/com/teamjo/techeermarket/domain/chats/dto/request/ChatReq.java

@@ -1,17 +1,12 @@
 package com.teamjo.techeermarket.domain.chats.dto.request;
 
-import lombok.AllArgsConstructor;
-import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
-@Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatReq {
   private Long chatRoomId; // 방 번호
   private String senderEmail;
   private String message;
+  private String createdAt;
 
 }

src/main/java/com/teamjo/techeermarket/domain/chats/dto/request/ChatRoomCreateReq.java

@@ -1,14 +1,8 @@
 package com.teamjo.techeermarket.domain.chats.dto.request;
 
-import lombok.AllArgsConstructor;
-import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
-@Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatRoomCreateReq {
   private Long productId;
 

src/main/java/com/teamjo/techeermarket/domain/chats/dto/response/ChatCreateRes.java

@@ -1,14 +1,10 @@
 package com.teamjo.techeermarket.domain.chats.dto.response;
 
-import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatCreateRes {
   private Long chatRoomId;
   private ProductInfo productInfo;

src/main/java/com/teamjo/techeermarket/domain/chats/dto/response/ChatInfo.java

@@ -1,14 +1,10 @@
 package com.teamjo.techeermarket.domain.chats.dto.response;
 
-import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatInfo {
   private String senderEmail;
   private String message;

src/main/java/com/teamjo/techeermarket/domain/chats/dto/response/ChatRes.java

@@ -1,15 +1,11 @@
 package com.teamjo.techeermarket.domain.chats.dto.response;
 
 import java.util.List;
-import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatRes {
   private ProductInfo productInfo;
   private String chatCreateAt;

src/main/java/com/teamjo/techeermarket/domain/chats/dto/response/ChatRoomRes.java

@@ -1,14 +1,10 @@
 package com.teamjo.techeermarket.domain.chats.dto.response;
 
-import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ChatRoomRes {
   private Long id;
   private Long productId;

src/main/java/com/teamjo/techeermarket/domain/chats/dto/response/ProductInfo.java

@@ -1,34 +1,18 @@
 package com.teamjo.techeermarket.domain.chats.dto.response;
 
-import com.teamjo.techeermarket.domain.products.entity.ProductState;
-import java.util.List;
-import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
-import lombok.NoArgsConstructor;
 
 @Data
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
 public class ProductInfo {
   private Long productId ;
-
   private String title ;
-
   private String thumbnailURL;  // 썸네일 이미지
-
   private String name;  // 작성자
-
   private Long userId ; // 작성자 id
-
   private int price ;
-
   private String createdAt ;
-
   private int likes ; // 좋아요수
-
   private int views;  // 뷰 수
-
-
 }

src/main/java/com/teamjo/techeermarket/domain/chats/mapper/ChatMapper.java

@@ -1,10 +1,13 @@
 package com.teamjo.techeermarket.domain.chats.mapper;
 
+import com.teamjo.techeermarket.domain.chats.dto.response.ChatCreateRes;
 import com.teamjo.techeermarket.domain.chats.dto.response.ChatInfo;
+import com.teamjo.techeermarket.domain.chats.dto.response.ChatRes;
 import com.teamjo.techeermarket.domain.chats.dto.response.ProductInfo;
 import com.teamjo.techeermarket.domain.chats.entity.Chat;
 import com.teamjo.techeermarket.domain.chats.entity.ChatRoom;
 import com.teamjo.techeermarket.domain.products.entity.Products;
+import java.util.List;
 import org.springframework.stereotype.Component;
 
 @Component
@@ -25,17 +28,18 @@ public ChatInfo toChatResDtoList(Chat chat) {
         .build();
   }
 
-  public ProductInfo toProductInfo(Products product){
-    return ProductInfo.builder()
-        .productId(product.getId())
-        .title(product.getTitle())
-        .thumbnailURL(product.getThumbnail())
-        .name(product.getUsers().getName())
-        .userId(product.getUsers().getId())
-        .price(product.getPrice())
-        .createdAt(product.getCreatedAt())
-        .likes(product.getHeart())
-        .views(product.getViews())
+  public ChatRes toChatResDto (List<ChatInfo> response, ProductInfo productInfo, String chatCreateAt) {
+    return ChatRes.builder()
+        .chatInfoList(response)
+        .productInfo(productInfo)
+        .chatCreateAt(chatCreateAt)
+        .build();
+  }
+
+  public ChatCreateRes toChatCreateResDto (Long chatRoomId, ProductInfo productInfo) {
+    return ChatCreateRes.builder()
+        .chatRoomId(chatRoomId)
+        .productInfo(productInfo)
         .build();
   }
 }

src/main/java/com/teamjo/techeermarket/domain/chats/service/ChatRoomService.java

@@ -10,12 +10,14 @@
 import com.teamjo.techeermarket.domain.chats.repository.ChatRepository;
 import com.teamjo.techeermarket.domain.chats.repository.ChatRoomRepository;
 import com.teamjo.techeermarket.domain.products.entity.Products;
+import com.teamjo.techeermarket.domain.products.mapper.ProductMapper;
 import com.teamjo.techeermarket.domain.products.repository.ProductRepository;
 import com.teamjo.techeermarket.domain.users.repository.UserRepository;
+import com.teamjo.techeermarket.global.exception.product.ProductNotFoundException;
 import com.teamjo.techeermarket.global.exception.user.UserNotFoundException;
-import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
-import java.util.Optional;
+import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -33,58 +35,67 @@ public class ChatRoomService {
   private final ChatRoomMapper chatRoomMapper;
   private final UserRepository userRepository;
   private final ChatMapper chatMapper;
+  private final ProductMapper productMapper;
 
   @Transactional
   public ChatCreateRes createChatRoom(Long productId, String buyer) {
 
-    Optional<Products> product = productRepository.findById(productId);
+    Products product = productRepository.findById(productId)
+        .orElseThrow(ProductNotFoundException::new);;
 
-    ChatRoom chatRoom = chatRoomMapper.toEntity(product.get(), product.get().getUsers().getEmail(), buyer);
+    ChatRoom chatRoom = chatRoomMapper.toEntity(product, product.getUsers().getEmail(), buyer);
     ChatRoom save = chatRoomRepository.save(chatRoom);
 
-    Products products = productRepository.findById(productId).get();
-    ProductInfo productInfo = chatMapper.toProductInfo(products);
+    ProductInfo productInfo = productMapper.toProductInfo(product);
 
-    ChatCreateRes chatCreateRes = new ChatCreateRes();
-    chatCreateRes.setChatRoomId(save.getId());
-    chatCreateRes.setProductInfo(productInfo);
-
-    return chatCreateRes;
+    return chatMapper.toChatCreateResDto(save.getId(), productInfo);
   }
 
   @Transactional(readOnly = true)
   public List<ChatRoomRes> findChatRoomByUserId(String userEmail, int pageNo, int pageSize) {
     Pageable pageable = PageRequest.of(pageNo - 1, pageSize, Sort.by("id").descending());  // 1페이지부터 시작하도록
     Page<Object[]> results = chatRoomRepository.findByUserIn(userEmail, pageable);
 
-    List<ChatRoomRes> chatRoomResponse = new ArrayList<>();
-    for (Object[] result : results) {
-      Long id = (Long) result[0];
-      Long productId = (Long) result[1];
-      String productTitle = (String) result[2];
-      String productLocation = (String) result[3];
-      int productPrice = (int) result[4];
-      String productThumbnail = (String) result[5];
-      String sellerEmail = (String) result[6];
-      String buyerEmail = (String) result[7];
-
-      String chatPartnerEmail = userEmail.equals(sellerEmail) ? buyerEmail : sellerEmail;
-      String chatPartnerName = userRepository.findUserByEmail(chatPartnerEmail).orElseThrow(
-          UserNotFoundException::new).getName();
-
-      String currentAt = "";
-      List<String> currentAtByChatRoomId = chatRepository.findCurrentAtByChatRoomId(id);
-      if (currentAtByChatRoomId.isEmpty()) {
-        currentAt = null;
-      } else {
-        currentAt = currentAtByChatRoomId.get(0);
-      }
-
-      ChatRoomRes response = new ChatRoomRes(id, productId, productTitle, productLocation, currentAt, productPrice, productThumbnail, chatPartnerName);
-      chatRoomResponse.add(response);
+    if (results.hasContent()) {
+      return results.getContent().stream()
+          .map(result -> mapToChatRoomRes(result, userEmail))
+          .collect(Collectors.toList());
+    } else {
+      return Collections.emptyList(); // 채팅 리스트가 없는 경우 빈 배열을 반환
     }
 
-    return chatRoomResponse;
+  }
+
+  private ChatRoomRes mapToChatRoomRes(Object[] result, String userEmail) {
+    Long id = (Long) result[0];
+    Long productId = (Long) result[1];
+    String productTitle = (String) result[2];
+    String productLocation = (String) result[3];
+    int productPrice = (int) result[4];
+    String productThumbnail = (String) result[5];
+    String sellerEmail = (String) result[6];
+    String buyerEmail = (String) result[7];
+
+    String chatPartnerEmail = userEmail.equals(sellerEmail) ? buyerEmail : sellerEmail;
+    String chatPartnerName = userRepository.findUserByEmail(chatPartnerEmail)
+        .orElseThrow(UserNotFoundException::new)
+        .getName();
+
+    String currentAt = chatRepository.findCurrentAtByChatRoomId(id)
+        .stream()
+        .findFirst()
+        .orElse(null);
+
+    return ChatRoomRes.builder()
+        .id(id)
+        .productId(productId)
+        .productTitle(productTitle)
+        .productLocation(productLocation)
+        .currentChatAt(currentAt)
+        .productPrice(productPrice)
+        .productThumbnail(productThumbnail)
+        .chatPartnerName(chatPartnerName)
+        .build();
   }
 
 }

src/main/java/com/teamjo/techeermarket/domain/chats/service/ChatService.java

@@ -10,12 +10,15 @@
 import com.teamjo.techeermarket.domain.chats.repository.ChatRepository;
 import com.teamjo.techeermarket.domain.chats.repository.ChatRoomRepository;
 import com.teamjo.techeermarket.domain.products.entity.Products;
+import com.teamjo.techeermarket.domain.products.mapper.ProductMapper;
 import com.teamjo.techeermarket.domain.products.repository.ProductRepository;
+import com.teamjo.techeermarket.global.exception.product.ProductNotFoundException;
 import java.util.List;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
+import com.teamjo.techeermarket.global.exception.chat.ChatNotFoundException;
 
 @Service
 @RequiredArgsConstructor
@@ -24,10 +27,13 @@ public class ChatService {
   private final ProductRepository productRepository;
   private final ChatRepository chatRepository;
   private final ChatMapper chatMapper;
+  private final ProductMapper productMapper;
 
   @Transactional
   public void saveMessage(ChatReq chatReq) {
-    ChatRoom chatRoom = chatRoomRepository.findById(chatReq.getChatRoomId()).orElseThrow();
+
+    ChatRoom chatRoom = chatRoomRepository.findById(chatReq.getChatRoomId())
+        .orElseThrow(ChatNotFoundException::new);
 
     Chat chat = chatMapper.toEntity(chatRoom, chatReq.getSenderEmail(), chatReq.getMessage());
 
@@ -36,24 +42,25 @@ public void saveMessage(ChatReq chatReq) {
 
   @Transactional(readOnly = true)
   public ChatRes getMessage(Long chatRoomId) {
+    // DB 조회 (채팅 리스트, 제품)
     List<Chat> chatList = chatRepository.findByChatRoomId(chatRoomId);
-    Long productId = chatRoomRepository.findById(chatRoomId).get().getProducts().getId();
-    Products products = productRepository.findById(productId).get();
-    ChatRes chatRes = new ChatRes();
 
+    ChatRoom chatRoom = chatRoomRepository.findById(chatRoomId)
+        .orElseThrow(ChatNotFoundException::new);
+    Long productId = chatRoom.getId();
+
+    Products products = productRepository.findById(productId)
+        .orElseThrow(ProductNotFoundException::new);
+
+    // 반환값 제작 (채팅 기록, 제품 정보, 첫 채팅 시각)
     List<ChatInfo> response = chatList.stream()
         .map(chatMapper::toChatResDtoList)
         .collect(Collectors.toList());
 
-    ProductInfo productInfo = chatMapper.toProductInfo(products);
-
-    String chatCreateAt = chatRepository.findCreateAtByChatRoomId(chatRoomId).get(0);
-
-    chatRes.setChatInfoList(response);
-    chatRes.setProductInfo(productInfo);
-    chatRes.setChatCreateAt(chatCreateAt);
+    ProductInfo productInfo = productMapper.toProductInfo(products);
 
+    String chatCreateAt = chatList.get(chatList.size() - 1).getCreatedAt();
 
-    return chatRes;
+    return chatMapper.toChatResDto(response, productInfo, chatCreateAt);
   }
 }