请问老师 通过点击各个分类查找并显示相应的类的图书的逻辑代码需要在book.xml中书写吗

//        private Book showPartBook(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//           String category=req.getParameter("category");
//            HttpSession session = req.getSession();
//            session.setAttribute("list", bookList);
//            List<Book> list=new ArrayList<Book>();
//           for(Book b:list){
//               if(b.getCategoryId().equals(category.categoryId)){
//                list.add(b);
//
//               }
//           }
//            return (Book) list;
             //req.setAttribute("bookList",list);
//            req.getRequestDispatcher("/WEB-INF/jsp/book.jsp").forward(req, resp);
//        }


book.xml:
<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE mapper SYSTEM "http://mybatis.org/dtd/mybatis-3-mapper.dtd" PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"/>

<!--namespace与包名类名一致-->

        <mapper namespace="com.imooc.oa.dao.BookDao">

    <!--id与方法名对应 parameterType与方法参数类型对应 resultType与方法返回类型对应-->

        <select resultType="com.imooc.oa.entity.Book" parameterType="Integer" id="selectById">select * from book </select>
    <select resultType="com.imooc.oa.entity.Book" parameterType="Integer" id="selectById">select * from book where category_id=#{value} </select>
   <insert id="insert" parameterType="com.imooc.oa.entity.Book" useGenerateKeys="true" keyProperty="id" keyColumn="id">
        INSERT INTO (category_id,name,level,price,img_path,create_time,update_time)
        VALUES(#{categoryId},#{name},#{level},#{price},#{imgPath},#{createTime},#{updateTime})
        </insert>
</mapper>​