CQRS 패턴 적용에 따른 리팩토링

- 레이어에서 command와 query로 분리
- 쿼리 객체에 맞는 구성 객체 추가 (MemberView, BookView)

src/main/java/com/study/bookcafe/application/book/BookService.java → src/main/java/com/study/bookcafe/application/command/book/BookService.java

@@ -1,14 +1,15 @@
-package com.study.bookcafe.application.book;
-
-import com.study.bookcafe.domain.book.Book;
+package com.study.bookcafe.application.command.book;
 
+import com.study.bookcafe.domain.command.book.Book;
 import java.util.Collection;
 import java.util.List;
 
 public interface BookService {
+
     // 도서 조회 (id)
     Book findById(long bookId);
 
     // 도서 목록 조회 (id list)
     List<Book> findByIds(Collection<Long> bookIds);
+
 }

src/main/java/com/study/bookcafe/application/book/BookServiceImpl.java → src/main/java/com/study/bookcafe/application/command/book/BookServiceImpl.java

@@ -1,9 +1,8 @@
-package com.study.bookcafe.application.book;
+package com.study.bookcafe.application.command.book;
 
-import com.study.bookcafe.domain.book.BookRepository;
-import com.study.bookcafe.domain.book.Book;
+import com.study.bookcafe.domain.command.book.Book;
+import com.study.bookcafe.domain.command.book.BookRepository;
 import org.springframework.stereotype.Service;
-
 import java.util.Collection;
 import java.util.List;
 

src/main/java/com/study/bookcafe/application/command/borrow/BorrowService.java

@@ -0,0 +1,15 @@
+package com.study.bookcafe.application.command.borrow;
+
+import com.study.bookcafe.domain.command.borrow.Borrow;
+import com.study.bookcafe.domain.command.borrow.Reservation;
+import java.util.Collection;
+
+public interface BorrowService {
+
+    // 도서 대출 저장
+    void save(Borrow borrow);
+    void save(Collection<Borrow> borrows);
+
+    // 도서 예약 저장
+    void save(Reservation reservation);
+}

src/main/java/com/study/bookcafe/application/command/borrow/BorrowServiceImpl.java

@@ -0,0 +1,50 @@
+package com.study.bookcafe.application.command.borrow;
+
+import com.study.bookcafe.domain.command.borrow.BorrowRepository;
+import com.study.bookcafe.domain.command.borrow.Borrow;
+import com.study.bookcafe.domain.command.borrow.Reservation;
+import org.springframework.stereotype.Service;
+import java.util.Collection;
+
+@Service
+public class BorrowServiceImpl implements BorrowService {
+    private final BorrowRepository borrowRepository;
+
+    public BorrowServiceImpl(BorrowRepository borrowRepository) {
+        this.borrowRepository = borrowRepository;
+    }
+
+    /**
+     * 새로운 대출을 저장한다.
+     *
+     * @param borrow  대출 정보
+     * @return 생성한 대출 정보
+     */
+    @Override
+    public void save(Borrow borrow) {
+        borrowRepository.save(borrow);
+    }
+
+    /**
+     * 새로운 여러 대출들을 저장한다.
+     *
+     * @param borrows 대출 목록
+     * @return 생성한 대출 정보 목록
+     */
+    @Override
+    public void save(Collection<Borrow> borrows) {
+        borrowRepository.save(borrows);
+    }
+
+    /**
+     * 새로운 예약을 저장한다.
+     *
+     * @param reservation 예악 정보
+     * @return 생성한 예약 정보
+     */
+    @Override
+    public void save(Reservation reservation) {
+        borrowRepository.save(reservation);
+    }
+
+}

src/main/java/com/study/bookcafe/application/command/member/MemberService.java

@@ -0,0 +1,16 @@
+package com.study.bookcafe.application.command.member;
+
+import com.study.bookcafe.domain.command.member.Member;
+import java.util.Collection;
+
+public interface MemberService {
+
+    // 회원 조회 (id)
+    Member findById(long memberId);
+
+    // 도서 대출
+    void borrowBook(long memberId, Collection<Long> bookIds);
+
+    // 도서 예약
+    void reserveBook(long memberId, long bookId);
+}

src/main/java/com/study/bookcafe/application/member/MemberServiceImpl.java → src/main/java/com/study/bookcafe/application/command/member/MemberServiceImpl.java

@@ -1,15 +1,15 @@
-package com.study.bookcafe.application.member;
+package com.study.bookcafe.application.command.member;
 
-import com.study.bookcafe.application.book.BookService;
-import com.study.bookcafe.application.borrow.BorrowService;
+import com.study.bookcafe.application.command.book.BookService;
+import com.study.bookcafe.application.command.borrow.BorrowService;
 import com.study.bookcafe.application.exception.BorrowableException;
 import com.study.bookcafe.application.exception.NonBorrowableMemberException;
-import com.study.bookcafe.domain.borrow.Reservation;
-import com.study.bookcafe.domain.member.MemberRepository;
-import com.study.bookcafe.domain.book.Book;
-import com.study.bookcafe.domain.borrow.Borrow;
-import com.study.bookcafe.domain.member.Member;
-import com.study.bookcafe.domain.borrow.BorrowDetails;
+import com.study.bookcafe.domain.command.book.Book;
+import com.study.bookcafe.domain.command.borrow.Borrow;
+import com.study.bookcafe.domain.command.borrow.Reservation;
+import com.study.bookcafe.domain.command.member.Member;
+import com.study.bookcafe.domain.command.member.MemberRepository;
+import com.study.bookcafe.domain.query.borrow.BorrowDetails;
 import org.springframework.stereotype.Service;
 
 import java.util.Collection;
@@ -44,38 +44,25 @@ public Member findById(long memberId) {
      *
      * @param memberId 회원 ID
      * @param bookIds 도서 ID 목록
-     * @return 대출
      */
     @Override
-    public List<Borrow> borrowBook(long memberId, Collection<Long> bookIds) {
+    public void borrowBook(long memberId, Collection<Long> bookIds) {
         Member member = findById(memberId);
         List<Book> books = bookService.findByIds(bookIds);
         List<Borrow> borrows = member.borrowBook(books);
 
-        if (borrows.isEmpty()) return borrows;
+        if (borrows.isEmpty()) return;
 
-        return borrowService.save(borrows);
-    }
-
-    /**
-     * 회원의 대출 목록을 조회한다.
-     *
-     * @param memberId 회원 ID
-     * @return 대출 목록
-     */
-    @Override
-    public List<BorrowDetails> findBorrows(long memberId) {
-        return borrowService.findBorrows(memberId);
+        borrowService.save(borrows);
     }
 
     /**
      * 회원이 도서 대출을 예약한다.
      * @param memberId 회원 ID
      * @param bookId 도서 ID
-     * @return 예약
      */
     @Override
-    public Reservation reserveBook(long memberId, long bookId) {
+    public void reserveBook(long memberId, long bookId) {
         Member member = findById(memberId);
         Book book = bookService.findById(bookId);
 
@@ -91,6 +78,6 @@ public Reservation reserveBook(long memberId, long bookId) {
 
         Reservation reservation = member.reserveBook(book);
 
-        return borrowService.save(reservation);
+        borrowService.save(reservation);
     }
 }

src/main/java/com/study/bookcafe/application/query/book/BookQueryService.java

@@ -0,0 +1,15 @@
+package com.study.bookcafe.application.query.book;
+
+import com.study.bookcafe.domain.query.book.BookView;
+
+import java.util.Collection;
+import java.util.List;
+
+public interface BookQueryService {
+
+    // 도서 조회 (id)
+    BookView findById(long bookId);
+
+    // 도서 목록 조회 (id list)
+    List<BookView> findByIds(Collection<Long> bookIds);
+}

src/main/java/com/study/bookcafe/application/query/book/BookQueryServiceImpl.java

@@ -0,0 +1,39 @@
+package com.study.bookcafe.application.query.book;
+
+import com.study.bookcafe.domain.query.book.BookQueryRepository;
+import com.study.bookcafe.domain.query.book.BookView;
+import org.springframework.stereotype.Service;
+import java.util.Collection;
+import java.util.List;
+
+@Service
+public class BookQueryServiceImpl implements BookQueryService {
+
+    private final BookQueryRepository bookQueryRepository;
+
+    public BookQueryServiceImpl(BookQueryRepository bookQueryRepository) {
+        this.bookQueryRepository = bookQueryRepository;
+    }
+
+    /**
+     * 도서를 ID로 조회한다.
+     *
+     * @param bookId 도서 ID
+     * @return 도서
+     */
+    @Override
+    public BookView findById(long bookId) {
+        return bookQueryRepository.findById(bookId);
+    }
+
+    /**
+     * 도서를 ID 목록으로 조회한다.
+     *
+     * @param bookIds 도서 ID 목록
+     * @return 도서 목록
+     */
+    @Override
+    public List<BookView> findByIds(Collection<Long> bookIds) {
+        return bookQueryRepository.findByIds(bookIds);
+    }
+}

src/main/java/com/study/bookcafe/application/query/borrow/BorrowQueryService.java

@@ -0,0 +1,11 @@
+package com.study.bookcafe.application.query.borrow;
+
+import com.study.bookcafe.domain.query.borrow.BorrowDetails;
+import java.util.List;
+
+public interface BorrowQueryService {
+
+    // 도서 대출 조회
+    List<BorrowDetails> findBorrows(long memberId);
+
+}