图书商城：图书模块

1、创建相关类

• cn.itcast.bookstore.book
• domain：Book
• dao：BookDao
• service :BookService
• web.servle：BookServlet

Book

public class Book {    private String bid;    private String bname;    private double price;    private String author;    private String image;    private Category category;    private boolean del;}

BookDao

public class BookDao {    private QueryRunner qr = new TxQueryRunner();    /**     * 查询所有图书     * @return     */    public List<Book> findAll() {        try {            String sql = "select * from book where del=false";            return qr.query(sql, new BeanListHandler<Book>(Book.class));        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    /**     * 按分类查询     * @param cid     * @return     */    public List<Book> findByCategory(String cid) {        try {            String sql = "select * from book where cid=? and del=false";            return qr.query(sql, new BeanListHandler<Book>(Book.class), cid);        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    /**     * 加载方法     * @param bid     * @return     */    public Book findByBid(String bid) {        try {            /*             * 我们需要在Book对象中保存Category的信息             */            String sql = "select * from book where bid=?";            Map<String,Object> map = qr.query(sql, new MapHandler(), bid);            /*             * 使用一个Map，映射出两个对象，再给这两个对象建立关系！             */            Category category = CommonUtils.toBean(map, Category.class);            Book book = CommonUtils.toBean(map, Book.class);            book.setCategory(category);            return book;        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    /**     * 查询指定分类下的图书本数     * @param cid     * @return     */    public int getCountByCid(String cid) {        try {            String sql = "select count(*) from book where cid=?";            Number cnt = (Number)qr.query(sql, new ScalarHandler(), cid);            return cnt.intValue();        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    /**     * 添加图书     * @param book     */    public void add(Book book) {        try {            String sql = "insert into book values(?,?,?,?,?,?)";            Object[] params = {book.getBid(), book.getBname(), book.getPrice(),                    book.getAuthor(), book.getImage(), book.getCategory().getCid()};            qr.update(sql, params);        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    /**     * 删除图书     * @param bid     */    public void delete(String bid) {        try {            String sql = "update book set del=true where bid=?";            qr.update(sql, bid);        } catch(SQLException e) {            throw new RuntimeException(e);        }    }    public void edit(Book book) {        try {            String sql = "update book set bname=?, price=?,author=?, image=?, cid=? where bid=?";            Object[] params = {book.getBname(), book.getPrice(),                    book.getAuthor(), book.getImage(),                     book.getCategory().getCid(), book.getBid()};            qr.update(sql, params);        } catch(SQLException e) {            throw new RuntimeException(e);        }    }}

BookService

public class BookService {    private BookDao bookDao = new BookDao();    /**     * 查询所有图书     * @return     */    public List<Book> findAll() {        return bookDao.findAll();    }    /**     * 按分类查询图书     * @param cid     * @return     */    public List<Book> findByCategory(String cid) {        return bookDao.findByCategory(cid);    }    public Book load(String bid) {        return bookDao.findByBid(bid);    }    /**     * 　添加图书     * @param book     */    public void add(Book book) {        bookDao.add(book);    }    public void delete(String bid) {        bookDao.delete(bid);    }    public void edit(Book book) {        bookDao.edit(book);    }}

BookServlet

public class BookServlet extends BaseServlet {    private BookService bookService = new BookService();    public String load(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        /*         * 1. 得到参数bid         * 2. 查询得到Book         * 3. 保存，转发到desc.jsp         */        request.setAttribute("book", bookService.load(request.getParameter("bid")));        return "f:/jsps/book/desc.jsp";    }    /**     * 查询所有图书     * @param request     * @param response     * @return     * @throws ServletException     * @throws IOException     */    public String findAll(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        request.setAttribute("bookList", bookService.findAll());        return "f:/jsps/book/list.jsp";    }    /**     * 按分类查询     * @param request     * @param response     * @return     * @throws ServletException     * @throws IOException     */    public String findByCategory(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        String cid = request.getParameter("cid");        request.setAttribute("bookList", bookService.findByCategory(cid));        return "f:/jsps/book/list.jsp";    }}

2、查询所有图书

流程：left.jsp（全部分类） -> BookServlet#findAll() -> /jsps/book/list.jsp

3、按分类查询图书

流程：left.jsp -> BookServlet#findByCategory() -> list.jsp

4、查询详细信息（加载）

流程：list.jsp（点击某一本书） -> BookServlet#load() -> desc.jsp