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