[FEAT] 채팅방에 참여한 유저 정보 리스트 반환 API

src/main/java/com/back/catchmate/domain/chat/controller/ChatRoomController.java

@@ -1,7 +1,9 @@
 package com.back.catchmate.domain.chat.controller;
 
 import com.back.catchmate.domain.chat.dto.ChatResponse;
-import com.back.catchmate.domain.chat.service.ChatRoomServiceImpl;
+import com.back.catchmate.domain.chat.service.ChatRoomService;
+import com.back.catchmate.domain.chat.service.UserChatRoomService;
+import com.back.catchmate.domain.user.dto.UserResponse.UserInfoList;
 import com.back.catchmate.global.dto.StateResponse;
 import com.back.catchmate.global.jwt.JwtValidation;
 import io.swagger.v3.oas.annotations.Operation;
@@ -22,7 +24,8 @@
 @RequiredArgsConstructor
 @RequestMapping("/chat-rooms")
 public class ChatRoomController {
-    private final ChatRoomServiceImpl chatRoomService;
+    private final ChatRoomService chatRoomService;
+    private final UserChatRoomService userChatRoomService;
 
     @GetMapping("/list")
     @Operation(summary = "내가 속한 채팅방 조회 API", description = "내가 속해있는 채팅방을 조회하는 API 입니다.")
@@ -38,4 +41,10 @@ public StateResponse leaveChatRoom(@JwtValidation Long userId,
                                        @PathVariable Long chatRoomId) {
         return chatRoomService.leaveChatRoom(userId, chatRoomId);
     }
+
+    @GetMapping("/{chatRoomId}/user-list")
+    @Operation(summary = "채팅방에 참여한 유저 정보 리스트 반환 API", description = "채팅방에 참여한 유저 정보 리스트 반환 API 입니다.")
+    public UserInfoList getUsersInChatRoom(@PathVariable Long chatRoomId) {
+        return userChatRoomService.getUserInfoList(chatRoomId);
+    }
 }

src/main/java/com/back/catchmate/domain/chat/converter/ChatRoomConverter.java

@@ -1,10 +1,8 @@
 package com.back.catchmate.domain.chat.converter;
 
 import com.back.catchmate.domain.board.converter.BoardConverter;
-import com.back.catchmate.domain.board.dto.BoardResponse;
 import com.back.catchmate.domain.board.dto.BoardResponse.BoardInfo;
 import com.back.catchmate.domain.board.entity.Board;
-import com.back.catchmate.domain.chat.dto.ChatResponse;
 import com.back.catchmate.domain.chat.dto.ChatResponse.ChatRoomInfo;
 import com.back.catchmate.domain.chat.dto.ChatResponse.PagedChatRoomInfo;
 import com.back.catchmate.domain.chat.entity.ChatRoom;

src/main/java/com/back/catchmate/domain/chat/converter/UserChatRoomConverter.java

@@ -2,18 +2,32 @@
 
 import com.back.catchmate.domain.chat.entity.ChatRoom;
 import com.back.catchmate.domain.chat.entity.UserChatRoom;
+import com.back.catchmate.domain.user.converter.UserConverter;
+import com.back.catchmate.domain.user.dto.UserResponse.UserInfoList;
 import com.back.catchmate.domain.user.entity.User;
+import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Component;
 
 import java.time.LocalDateTime;
+import java.util.List;
+import java.util.stream.Collectors;
 
 @Component
+@RequiredArgsConstructor
 public class UserChatRoomConverter {
+    private final UserConverter userConverter;
+
     public UserChatRoom toEntity(User user, ChatRoom chatRoom) {
         return UserChatRoom.builder()
                 .user(user)
                 .chatRoom(chatRoom)
                 .joinedAt(LocalDateTime.now())
                 .build();
     }
+
+    public UserInfoList toUserInfoList(List<UserChatRoom> userChatRoomList) {
+        return new UserInfoList(userChatRoomList.stream()
+                .map(userChatRoom -> userConverter.toUserInfo(userChatRoom.getUser()))
+                .collect(Collectors.toList()));
+    }
 }

src/main/java/com/back/catchmate/domain/chat/dto/ChatResponse.java

@@ -1,7 +1,6 @@
 package com.back.catchmate.domain.chat.dto;
 
 import com.back.catchmate.domain.board.dto.BoardResponse.BoardInfo;
-import com.back.catchmate.domain.notification.dto.NotificationResponse;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Getter;

src/main/java/com/back/catchmate/domain/chat/repository/ChatMessageRepository.java

@@ -1,9 +1,7 @@
 package com.back.catchmate.domain.chat.repository;
 
 import com.back.catchmate.domain.chat.entity.ChatMessage;
-import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
-import org.springframework.data.mongodb.repository.Query;
 import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
 import reactor.core.publisher.Flux;
 

src/main/java/com/back/catchmate/domain/chat/repository/ChatRoomRepository.java

@@ -1,7 +1,6 @@
 package com.back.catchmate.domain.chat.repository;
 
 import com.back.catchmate.domain.chat.entity.ChatRoom;
-import kotlin.OptIn;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;

src/main/java/com/back/catchmate/domain/chat/repository/UserChatRoomRepository.java

@@ -6,6 +6,7 @@
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Query;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface UserChatRoomRepository extends JpaRepository<UserChatRoom, Long> {
@@ -18,4 +19,6 @@ public interface UserChatRoomRepository extends JpaRepository<UserChatRoom, Long
             "WHERE ucr.user.id = :userId " +
             "ORDER BY cr.lastMessageAt DESC")
     Page<UserChatRoom> findAllByUserId(Long userId, Pageable pageable);
+
+    List<UserChatRoom> findByChatRoomId(Long chatRoomId);
 }

src/main/java/com/back/catchmate/domain/chat/service/UserChatRoomService.java

@@ -0,0 +1,7 @@
+package com.back.catchmate.domain.chat.service;
+
+import com.back.catchmate.domain.user.dto.UserResponse.UserInfoList;
+
+public interface UserChatRoomService {
+    UserInfoList getUserInfoList(Long chatRoomId);
+}

src/main/java/com/back/catchmate/domain/chat/service/UserChatRoomServiceImpl.java

@@ -0,0 +1,25 @@
+package com.back.catchmate.domain.chat.service;
+
+import com.back.catchmate.domain.chat.converter.UserChatRoomConverter;
+import com.back.catchmate.domain.chat.entity.UserChatRoom;
+import com.back.catchmate.domain.chat.repository.UserChatRoomRepository;
+import com.back.catchmate.domain.user.dto.UserResponse;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class UserChatRoomServiceImpl implements UserChatRoomService {
+    private final UserChatRoomRepository userChatRoomRepository;
+    private final UserChatRoomConverter userChatRoomConverter;
+
+    @Override
+    @Transactional(readOnly = true)
+    public UserResponse.UserInfoList getUserInfoList(Long chatRoomId) {
+        List<UserChatRoom> userChatRoomList = userChatRoomRepository.findByChatRoomId(chatRoomId);
+        return userChatRoomConverter.toUserInfoList(userChatRoomList);
+    }
+}

src/main/java/com/back/catchmate/domain/user/dto/UserResponse.java

@@ -9,6 +9,7 @@
 
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.util.List;
 
 public abstract class UserResponse {
     @Getter
@@ -41,6 +42,14 @@ public static class UserInfo {
         private String watchStyle;
     }
 
+    @Getter
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class UserInfoList {
+        private List<UserInfo> userInfoList;
+    }
+
     @Getter
     @Builder
     @AllArgsConstructor