java中的接口是类吗
215
2023-06-29
javaweb图书商城设计之图书模块(4)
javaweb图书商城设计之图书模块(4)
本文接着上一篇图书商城分类模块进行学习，供大家参考，具体内容如下
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 imajQtzRge;
private Category category;
private boolean del;
}
BookDao
public class BookDao {
private QueryRunner qr = new TxQueryRunner();
/**
* 查询所有图书
* @return
*/
public List
try {
String sql = "select * from book where del=false";
return qr.query(sql, new BeanListHandler
} catch(SQLException e) {
throw new RuntimeException(e);
}
}
/**
* 按分类查询
* @param cid
* @return
*/
public List
try {
String sql = "select * from book where cid=? and del=false";
return qr.query(sql, new BeanListHandler
} 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
/*
* 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
return bookDao.findAll();
}
/**
* 按分类查询图书
* @param cid
* @return
*/
public List
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
*jQtzR @throws IOException
*/
public String findAll(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setAttribute("bookList", bookService.findAll());
return "f:/jsps/book/list.jsp";
jQtzR }
/**
* 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
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