添加用户收藏书籍、取消收藏书籍、获取书籍收藏状态功能（后端+数据库）；更新Api文档

bookshelfplus/src/main/java/plus/bookshelf/Service/Service/BookService.java

@@ -5,6 +5,7 @@ import plus.bookshelf.Dao.DO.BookDO;
 import plus.bookshelf.Service.Model.BookModel;
 
 import java.util.List;
+import java.util.Map;
 
 public interface BookService {
     /**
@@ -29,4 +30,30 @@ public interface BookService {
      * @return
      */
     Integer addBook(BookModel bookModel) throws BusinessException;
+
+    /**
+     * 用户收藏书籍
+     *
+     * @param bookId 书籍id
+     * @return
+     */
+    Boolean addFavorites(Integer userId, Integer bookId) throws BusinessException;
+
+    /**
+     * 用户取消收藏书籍
+     * @param userId
+     * @param bookId
+     * @return
+     * @throws BusinessException
+     */
+    Boolean removeFavorites(Integer userId, Integer bookId) throws BusinessException;
+
+    /**
+     * 获取用户收藏状态
+     * @param userId 用户id
+     * @param bookId 书籍id
+     * @return
+     * @throws BusinessException
+     */
+    Map getFavoritesStatus(Integer userId, Integer bookId) throws BusinessException;
 }