[✨ feat] 그룹 정보 보기 API 구현

build.gradle

@@ -23,6 +23,10 @@ repositories {
 	mavenCentral()
 }
 
+ext {
+	set('queryDslVersion', "5.0.0")
+}
+
 dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 	implementation 'org.springframework.boot:spring-boot-starter-web'
@@ -38,6 +42,12 @@ dependencies {
 
 	// Actuator
 	implementation 'org.springframework.boot:spring-boot-starter-actuator'
+
+	// QueryDSL
+	implementation "com.querydsl:querydsl-jpa:${queryDslVersion}:jakarta"
+	annotationProcessor "com.querydsl:querydsl-apt:${queryDslVersion}:jakarta"
+	annotationProcessor "jakarta.annotation:jakarta.annotation-api"
+	annotationProcessor "jakarta.persistence:jakarta.persistence-api"
 }
 
 tasks.named('test') {

src/main/java/org/noostak/global/config/QueryDslConfig.java

@@ -0,0 +1,19 @@
+package org.noostak.global.config;
+
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.PersistenceContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class QueryDslConfig {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Bean
+    public JPAQueryFactory jpaQueryFactory() {
+        return new JPAQueryFactory(entityManager);
+    }
+}

src/main/java/org/noostak/group/api/GroupController.java

@@ -4,15 +4,15 @@
 import org.noostak.global.success.SuccessResponse;
 import org.noostak.group.application.GroupService;
 import org.noostak.group.dto.request.GroupCreateRequest;
-import org.noostak.group.dto.response.GroupCreateResponse;
-import org.noostak.group.dto.response.GroupsRetrieveResponse;
+import org.noostak.group.dto.response.create.GroupCreateResponse;
+import org.noostak.group.dto.response.info.GroupInfoResponse;
+import org.noostak.group.dto.response.retrieve.GroupsRetrieveResponse;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
 import java.io.IOException;
 
-import static org.noostak.group.common.success.GroupSuccessCode.GROUP_CREATED;
-import static org.noostak.group.common.success.GroupSuccessCode.GROUP_RETRIEVED;
+import static org.noostak.group.common.success.GroupSuccessCode.*;
 
 @RestController
 @RequestMapping("/api/v1/groups")
@@ -41,4 +41,14 @@ public ResponseEntity<SuccessResponse<GroupsRetrieveResponse>> getGroups(
         GroupsRetrieveResponse groups = groupService.findGroups(memberId);
         return ResponseEntity.ok(SuccessResponse.of(GROUP_RETRIEVED, groups));
     }
+
+    @GetMapping("/{groupId}/members")
+    public ResponseEntity<SuccessResponse<GroupInfoResponse>> getGroupInfo(
+            // @AuthenticationPrincipal Long memberId,
+            @PathVariable Long groupId
+    ) {
+        Long memberId = 1L;
+        GroupInfoResponse groupInfo = groupService.getGroupInfo(memberId, groupId);
+        return ResponseEntity.ok(SuccessResponse.of(GROUP_INFO, groupInfo));
+    }
 }

src/main/java/org/noostak/group/application/GroupCreateService.java

@@ -1,7 +1,7 @@
 package org.noostak.group.application;
 
 import org.noostak.group.dto.request.GroupCreateRequest;
-import org.noostak.group.dto.response.GroupCreateInternalResponse;
+import org.noostak.group.dto.response.create.GroupCreateInternalResponse;
 
 import java.io.IOException;
 

src/main/java/org/noostak/group/application/GroupCreateServiceImpl.java

@@ -9,13 +9,12 @@
 import org.noostak.group.domain.vo.GroupName;
 import org.noostak.group.domain.vo.GroupProfileImageKey;
 import org.noostak.group.dto.request.GroupCreateRequest;
-import org.noostak.group.dto.response.GroupCreateInternalResponse;
+import org.noostak.group.dto.response.create.GroupCreateInternalResponse;
 import org.noostak.infra.KeyAndUrl;
 import org.noostak.infra.S3DirectoryPath;
 import org.noostak.infra.S3Service;
 import org.noostak.member.domain.Member;
 import org.noostak.member.domain.MemberRepository;
-import org.springframework.context.annotation.Primary;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.multipart.MultipartFile;

src/main/java/org/noostak/group/application/GroupInfoService.java

@@ -0,0 +1,7 @@
+package org.noostak.group.application;
+
+import org.noostak.group.dto.response.info.GroupInfoResponse;
+
+public interface GroupInfoService {
+    GroupInfoResponse getGroupInfo(Long memberId, Long groupId);
+}

src/main/java/org/noostak/group/application/GroupInfoServiceImpl.java

@@ -0,0 +1,91 @@
+package org.noostak.group.application;
+
+import lombok.RequiredArgsConstructor;
+import org.noostak.group.common.exception.GroupErrorCode;
+import org.noostak.group.common.exception.GroupException;
+import org.noostak.group.domain.Group;
+import org.noostak.group.domain.GroupRepository;
+import org.noostak.group.dto.response.info.GroupInfoResponse;
+import org.noostak.group.dto.response.info.GroupMemberInfoResponse;
+import org.noostak.group.dto.response.info.GroupSummaryResponse;
+import org.noostak.infra.S3Service;
+import org.noostak.member.domain.Member;
+import org.noostak.membergroup.domain.MemberGroupRepository;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class GroupInfoServiceImpl implements GroupInfoService {
+
+    private final GroupRepository groupRepository;
+    private final MemberGroupRepository memberGroupRepository;
+    private final S3Service s3Service;
+
+    @Override
+    public GroupInfoResponse getGroupInfo(final Long memberId, final Long groupId) {
+        Group group = findGroupById(groupId);
+
+        Member member = findMemberInGroup(memberId, groupId);
+        GroupMemberInfoResponse myInfoResponse = convertToGroupMemberInfo(member);
+
+
+        GroupMemberInfoResponse groupHostInfo = findGroupHost(groupId);
+
+        List<GroupMemberInfoResponse> groupMembersInfo = findGroupMembers(groupId);
+
+        GroupSummaryResponse groupSummaryResponse = convertToGroupSummaryResponse(group, groupHostInfo, groupMembersInfo);
+
+        return GroupInfoResponse.of(myInfoResponse, groupSummaryResponse);
+    }
+
+    private Member findMemberInGroup(Long memberId, Long groupId) {
+        return memberGroupRepository.findMembersByGroupId(groupId).stream()
+                .filter(m -> m.getMemberId().equals(memberId))
+                .findFirst()
+                .orElseThrow(() -> new GroupException(GroupErrorCode.MEMBER_NOT_FOUND));
+    }
+
+    private Group findGroupById(Long groupId) {
+        return groupRepository.findById(groupId)
+                .orElseThrow(() -> new GroupException(GroupErrorCode.GROUP_NOT_FOUND));
+    }
+
+    private GroupMemberInfoResponse findGroupHost(Long groupId) {
+        Member host = memberGroupRepository.findGroupHostByGroupId(groupId);
+        if (host == null) throw new GroupException(GroupErrorCode.GROUP_MEMBER_NOT_FOUND);
+
+        return convertToGroupMemberInfo(host);
+    }
+
+    private List<GroupMemberInfoResponse> findGroupMembers(Long groupId) {
+        return memberGroupRepository.findMembersByGroupId(groupId).stream()
+                .map(this::convertToGroupMemberInfo)
+                .toList();
+    }
+
+    private GroupMemberInfoResponse convertToGroupMemberInfo(Member member) {
+        return GroupMemberInfoResponse.of(
+                member.getName().value(),
+                s3Service.getImageUrl(member.getKey().value())
+        );
+    }
+
+    private GroupSummaryResponse convertToGroupSummaryResponse(Group group, GroupMemberInfoResponse hostInfo, List<GroupMemberInfoResponse> membersInfo) {
+        String groupProfileImageUrl = getGroupProfileImageUrl(group);
+
+        return GroupSummaryResponse.of(
+                hostInfo,
+                group.getName().value(),
+                groupProfileImageUrl,
+                group.getCount().value(),
+                group.getCode().value(),
+                membersInfo
+        );
+    }
+
+    private String getGroupProfileImageUrl(Group group) {
+        return s3Service.getImageUrl(group.getKey().value());
+    }
+}

src/main/java/org/noostak/group/application/GroupRetrieveService.java

@@ -1,6 +1,6 @@
 package org.noostak.group.application;
 
-import org.noostak.group.dto.response.GroupsRetrieveResponse;
+import org.noostak.group.dto.response.retrieve.GroupsRetrieveResponse;
 
 public interface GroupRetrieveService {
     GroupsRetrieveResponse findGroups(Long memberId);

src/main/java/org/noostak/group/application/GroupRetrieveServiceImpl.java

@@ -3,14 +3,11 @@
 import lombok.RequiredArgsConstructor;
 import org.noostak.group.common.exception.GroupErrorCode;
 import org.noostak.group.common.exception.GroupException;
-import org.noostak.group.domain.Groups;
-import org.noostak.group.dto.response.GroupInternalRetrieveResponse;
-import org.noostak.group.dto.response.GroupRetrieveResponse;
-import org.noostak.group.dto.response.GroupsRetrieveResponse;
+import org.noostak.group.domain.Group;
+import org.noostak.group.dto.response.retrieve.GroupRetrieveResponse;
+import org.noostak.group.dto.response.retrieve.GroupsRetrieveResponse;
 import org.noostak.infra.S3Service;
-import org.noostak.membergroup.domain.MemberGroup;
 import org.noostak.membergroup.domain.MemberGroupRepository;
-import org.noostak.membergroup.domain.MemberGroups;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -24,35 +21,28 @@ public class GroupRetrieveServiceImpl implements GroupRetrieveService {
 
     @Override
     public GroupsRetrieveResponse findGroups(Long memberId) {
-        MemberGroups memberGroups = getMemberGroups(memberId);
-        Groups groups = convertToGroups(memberGroups);
+        List<Group> groups = getGroupsByMemberId(memberId);
+        validateGroups(groups);
         return convertToResponse(groups);
     }
 
-    private MemberGroups getMemberGroups(Long memberId) {
-        List<MemberGroup> foundMemberGroups = memberGroupRepository.findByMemberId(memberId);
-        MemberGroups memberGroups = MemberGroups.of(foundMemberGroups);
+    private List<Group> getGroupsByMemberId(Long memberId) {
+        return memberGroupRepository.findGroupsByMemberId(memberId);
+    }
 
-        if (memberGroups.isEmpty()) {
+    private void validateGroups(List<Group> groups) {
+        if (groups.isEmpty()) {
             throw new GroupException(GroupErrorCode.GROUP_NOT_FOUND);
         }
-
-        return memberGroups;
-    }
-
-    private Groups convertToGroups(MemberGroups memberGroups) {
-        return Groups.of(memberGroups.toGroups());
     }
 
-    private GroupsRetrieveResponse convertToResponse(Groups groups) {
-        List<GroupInternalRetrieveResponse> internalResponses = groups.getGroups().stream()
-                .map(group -> GroupInternalRetrieveResponse.of(group, s3Service.getImageUrl(group.getKey().value())))
+    private GroupsRetrieveResponse convertToResponse(List<Group> groups) {
+        List<GroupRetrieveResponse> groupResponses = groups.stream()
+                .map(group -> GroupRetrieveResponse.of(
+                        group,
+                        s3Service.getImageUrl(group.getKey().value())
+                ))
                 .toList();
-
-        List<GroupRetrieveResponse> groupResponses = internalResponses.stream()
-                .map(internal -> GroupRetrieveResponse.of(internal.group(), internal.groupProfileImageUrl()))
-                .toList();
-
         return GroupsRetrieveResponse.of(groupResponses);
     }
 }

src/main/java/org/noostak/group/application/GroupService.java

@@ -2,9 +2,10 @@
 
 import lombok.RequiredArgsConstructor;
 import org.noostak.group.dto.request.GroupCreateRequest;
-import org.noostak.group.dto.response.GroupCreateInternalResponse;
-import org.noostak.group.dto.response.GroupCreateResponse;
-import org.noostak.group.dto.response.GroupsRetrieveResponse;
+import org.noostak.group.dto.response.create.GroupCreateInternalResponse;
+import org.noostak.group.dto.response.create.GroupCreateResponse;
+import org.noostak.group.dto.response.info.GroupInfoResponse;
+import org.noostak.group.dto.response.retrieve.GroupsRetrieveResponse;
 import org.springframework.stereotype.Service;
 
 import java.io.IOException;
@@ -15,6 +16,7 @@ public class GroupService {
 
     private final GroupCreateService groupCreateService;
     private final GroupRetrieveService groupRetrieveService;
+    private final GroupInfoService groupInfoService;
 
     public GroupCreateResponse createGroup(Long memberId, GroupCreateRequest request) throws IOException {
         GroupCreateInternalResponse response = groupCreateService.createGroup(memberId, request);
@@ -24,4 +26,8 @@ public GroupCreateResponse createGroup(Long memberId, GroupCreateRequest request
     public GroupsRetrieveResponse findGroups(Long memberId) {
         return groupRetrieveService.findGroups(memberId);
     }
+
+    public GroupInfoResponse getGroupInfo(Long memberId, Long groupId) {
+        return groupInfoService.getGroupInfo(memberId, groupId);
+    }
 }

src/main/java/org/noostak/group/common/exception/GroupErrorCode.java

@@ -27,6 +27,8 @@ public enum GroupErrorCode implements ErrorCode {
 
     GROUP_NOT_FOUND(HttpStatus.NOT_FOUND, "그룹을 찾을 수 없습니다."),
     GROUP_MEMBER_NOT_FOUND(HttpStatus.NOT_FOUND, "그룹 멤버를 찾을 수 없습니다."),
+
+    MEMBER_NOT_FOUND(HttpStatus.NOT_FOUND, "멤버를 찾을 수 없습니다.")
     ;
 
     public static final String PREFIX = "[GROUP ERROR] ";

src/main/java/org/noostak/group/common/success/GroupSuccessCode.java

@@ -11,6 +11,8 @@ public enum GroupSuccessCode implements SuccessCode {
     GROUP_CREATED(HttpStatus.CREATED, "그룹이 성공적으로 생성되었습니다."),
 
     GROUP_RETRIEVED(HttpStatus.OK, "그룹이 성공적으로 조회되었습니다."),
+
+    GROUP_INFO(HttpStatus.OK, "그룹 정보가 성공적으로 조회되었습니다.")
     ;
 
     private final HttpStatus status;

src/main/java/org/noostak/group/dto/response/GroupCreateInternalResponse.java → src/main/java/org/noostak/group/dto/response/create/GroupCreateInternalResponse.java

@@ -1,4 +1,4 @@
-package org.noostak.group.dto.response;
+package org.noostak.group.dto.response.create;
 
 
 import org.noostak.group.domain.Group;

src/main/java/org/noostak/group/dto/response/GroupCreateResponse.java → src/main/java/org/noostak/group/dto/response/create/GroupCreateResponse.java

@@ -1,4 +1,4 @@
-package org.noostak.group.dto.response;
+package org.noostak.group.dto.response.create;
 
 import org.noostak.group.domain.Group;
 

src/main/java/org/noostak/group/dto/response/info/GroupInfoResponse.java

@@ -0,0 +1,10 @@
+package org.noostak.group.dto.response.info;
+
+public record GroupInfoResponse(
+        GroupMemberInfoResponse myInfo,
+        GroupSummaryResponse groupInfo
+) {
+    public static GroupInfoResponse of(final GroupMemberInfoResponse myInfo, final GroupSummaryResponse groupInfo) {
+        return new GroupInfoResponse(myInfo, groupInfo);
+    }
+}

src/main/java/org/noostak/group/dto/response/info/GroupMemberInfoResponse.java

@@ -0,0 +1,10 @@
+package org.noostak.group.dto.response.info;
+
+public record GroupMemberInfoResponse(
+        String memberName,
+        String memberProfileImageUrl
+) {
+    public static GroupMemberInfoResponse of(final String memberName, final String memberProfileImageUrl) {
+        return new GroupMemberInfoResponse(memberName, memberProfileImageUrl);
+    }
+}

src/main/java/org/noostak/group/dto/response/info/GroupSummaryResponse.java

@@ -0,0 +1,15 @@
+package org.noostak.group.dto.response.info;
+
+import java.util.List;
+
+public record GroupSummaryResponse(
+        GroupMemberInfoResponse groupHostInfo,
+        String groupName,
+        String groupProfileImageUrl,
+        Long groupMemberCount,
+        String groupInvitationCode,
+        List<GroupMemberInfoResponse> groupMemberInfo
+) {
+    public static GroupSummaryResponse of(final GroupMemberInfoResponse groupHostInfo, final String groupName, final String groupProfileImageUrl, final Long groupMemberCount, final String groupInvitationCode, final List<GroupMemberInfoResponse> groupMemberInfo) {
+        return new GroupSummaryResponse(groupHostInfo, groupName, groupProfileImageUrl, groupMemberCount, groupInvitationCode, groupMemberInfo);}
+}

src/main/java/org/noostak/group/dto/response/GroupInternalRetrieveResponse.java → src/main/java/org/noostak/group/dto/response/retrieve/GroupInternalRetrieveResponse.java

@@ -1,4 +1,4 @@
-package org.noostak.group.dto.response;
+package org.noostak.group.dto.response.retrieve;
 
 import org.noostak.group.domain.Group;
 

src/main/java/org/noostak/group/dto/response/GroupRetrieveResponse.java → src/main/java/org/noostak/group/dto/response/retrieve/GroupRetrieveResponse.java

@@ -1,4 +1,4 @@
-package org.noostak.group.dto.response;
+package org.noostak.group.dto.response.retrieve;
 
 import org.noostak.group.domain.Group;
 

src/main/java/org/noostak/group/dto/response/GroupsRetrieveResponse.java → src/main/java/org/noostak/group/dto/response/retrieve/GroupsRetrieveResponse.java

@@ -1,4 +1,4 @@
-package org.noostak.group.dto.response;
+package org.noostak.group.dto.response.retrieve;
 
 import java.util.List;