实验四基于MVC模式的网上教材订购（第18章实验指导4）需求分析：基于ＭＶＣ模式，制作一个购物程序，让学生可以在网页上订购教材。

该系统由三个界面组成。

１、准备数据

此处使用MySQL 5.5 厂商驱动，

数据库名：SCHOOL

用户名为:sa

密码:limei6875

数据表：

包含图书编号、图书名称和图书价格

创建表的脚本如下：

CREATE TABLE t_book(

bookno varchar(40) NOT NULL,

bookname varchar(40) default NULL,

bookprice float default NULL

)

插入一些数据.

2、编写DBOPer数据库操作类（基础类）

略（同前面的项目）

3、编写过滤器，解决中文处理问题。

(同上一个实验）

4、在DBOPer的基础上编写DAO和VO

本项目中，应该在DAO中查询所有的图书，图书的信息用VO封装

（1）编写BookDao.java

package dao;

public class BookDao {

private Connection conn=null;

//返回所有的图书

public HashMap getAllBook() throws Exception{

HashMap hm=new HashMap();

String sql="select BOOKNO,BOOKNAME,BOOKPRICE FROM T_BOOK";

ResultSet rs=this.executeQuery(sql,null);

while(rs.next()){

// 创建VO对象

Book book=new Book();

// 将查询到的结果保存到ＶＯ对象中

book.setBookno(rs.getString("bookno"));

// String name=new String(rs.getString("bookname").getBytes("ISO-8859-1"),"gb2312"); book.setBookname(rs.getString("bookname"));

book.setBookprice(rs.getFloat("bookprice"));

// 将VO对象（键值对）放入HashMap中

hm.put(book.getBookno(),book);

}

return hm; }

}

----------------------------------------------------------------------------- （2）编写VO：Book.java

----------------------------------------------------------------------------- package vo;

public class Book implements Serializable {

private String bookno;

private String bookname;

private double bookprice;

private int booknumber;

//略去setter/getter方法

}

----------------------------------------------------------------------------- （3）编写一个测试类，测试Dao中的方法（用来测试该方法的正确性）

TestDao.java

----------------------------------------------------

package dao;

public class TestDao {

public static void main(String[] args) throws Exception {

HashMap books=new HashMap();

BookDao dao=new BookDao();

books=dao.getAllBook();

Set set=books.keySet();

Iterator ite=set.iterator();

System.out.println("书号书名价格");

while(ite.hasNext()){

String bookno=(String)ite.next();

Book book=(Book)books.get(bookno);

System.out.println( book.getBookno()+book.getBookname()+" "+book.getBookprice());

}

}

}

-------------------------------------------------------------------------------

运行Java类：检验是否能从数据库中读出所有图书（不用启动服务器，直接运行Java代码即可）

3 、编写SessionListener.java

SessionListener.java是一个监听器，负责对session的内容进行初始化。

SessionListener.java

-----------------------------------------------------------------------------

package listener;

public class SessionListener implements HttpSessionListener {

public void sessionCreated(HttpSessionEvent se) {

HttpSession session=se.getSession();

// 初始化购物车

HashMap books=new HashMap();

session.setAttribute("books", books);

// 初始化总钱数

session.setAttribute("money", 0.00);

System.out.println("创建了session");

}

public void sessionDestroyed(HttpSessionEvent se) {

}

}

-----------------------------------------------------------------------------

配置监听器：

web.xml

-----------------------------------------------------------------

listener.SessionListener

-----------------------------------------------------------------

4 、编写InitServlet.java和showAllBook.jsp

用户首先访问的是InitServlet，负责查询所有的图书，然后跳转到showAllBook.jsp

InitServlet.java

-----------------------------------------------------------------------------

package servlet;

public class InitServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

doPost(request,response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

BookDao bookDao=new BookDao();

HashMap allbook=null;

try {

allbook=bookDao.getAllBook();

} catch (Exception e) {

e.printStackTrace();

}

// 将所有图书放入session中

HttpSession session=request.getSession();

session.setAttribute("allbook", allbook);

// 跳转到显示所有图书界面

response.sendRedirect("/ProjWeb18/showAllBook.jsp");

}

}

------------------------------------------------------------------------------------ showAllBook.jsp

------------------------------------------------------------------------

<%@ page language="java" import="java.util.*,vo.Book" pageEncoding="gb2312"%>

欢迎选购图书

<%

HashMap allbook=(HashMap)session.getAttribute("allbook");

%>

<%

//将HashMap中的键取出翻入Set集中（Set集中的元素不可重复）

Set set=allbook.keySet();

//创建Iterator对象

Iterator ite=set.iterator();

while(ite.hasNext()){

String bookno=(String)ite.next();//取出书号

Book book=(Book)allbook.get(bookno);//取出该书号对应的图书对象%>

<%

}

%>

查看购物车

--------------------------------------------------------------------------

5、编写buyForm.jsp和AddServlet.java

---------------------------------------------------------------

buyform.jsp负责显示买书表单

<%@ page language="java" import="java.util.*,vo.Book" pageEncoding="UTF-8"%>

购买图书

<%

String bookno=request.getParameter("bookno");

HashMap allbook=(HashMap)session.getAttribute("allbook");//取出所有的图书键值对Book book=(Book)allbook.get(bookno);//取出该书号对应的图书对象

%>

欢迎购买:<%=book.getBookname() %>

----------------------------------------------------------------------------------

表单提交到AddServlet，代码中用到了隐藏表单：

AddServlet.java

---------------------------------------------------------

package servlet;

public class AddServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request,response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

request.setCharacterEncoding("UTF-8");

HttpSession session=request.getSession();

HashMap books=(HashMap)session.getAttribute("books");

// 获取提交的内容

String bookno=request.getParameter("bookno");

String bookname=request.getParameter("bookname");

String strbookprice=request.getParameter("bookprice");

String strbooknumber=request.getParameter("booknumber");

// 存入购物车

Book book=new Book();

book.setBookno(bookno);

book.setBookname(bookname);

//将读取的价格转为双精度实数

double bookprice=Double.parseDouble(strbookprice);

book.setBookprice(bookprice);

//将读取的图书数量转为整型数据

int booknumber=Integer.parseInt(strbooknumber);

book.setBooknumber(booknumber);

books.put(bookno, book);

// 总钱数增加

double money=(Double)session.getAttribute("money");

money=money+bookprice*booknumber;

session.setAttribute("money", money);

response.sendRedirect("/ProjWeb18/showCart.jsp");

}

}

--------------------------------------------------------------------

6、编写showCart.jsp和RemoveServlet .java

showCart.jsp负责显示购物车的内容。

showCart.jsp

----------------------------------------------------------------------------------

<%@ page language="java" import="java.util.*,vo.Book" pageEncoding="UTF-8"%>

显示购物车

<%

HashMap books=(HashMap)session.getAttribute("books");//从session中取出所有的键值对Set set=books.keySet();//取出HashMap中的键的集合，存入Set集中（该集中的元素不能重复）Iterator ite=set.iterator();//创建迭代器，用来遍历Set集中的所有元素

while(ite.hasNext()){

String bookno=(String)ite.next();//取出书号

Book book=(Book)books.get(bookno);//取出对应于该书号的图书对象

%>

<%

}

%>

现金总额：<%=session.getAttribute("money") %>

继续购买

---------------------------------------------------------------------------------- RemoveServlet.java

----------------------------------------------------------------------------------

package servlet;

public class RemoveServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doPost(request,response);

}

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

String bookno=request.getParameter("bookno");

HttpSession session=request.getSession();

HashMap books=(HashMap)session.getAttribute("books");

Book book=(Book)books.get(bookno);

float money=(Float)session.getAttribute("money");

money=money-book.getBooknumber()*book.getBookprice();

session.setAttribute("money", money);

books.remove(bookno);

response.sendRedirect("/ProjWeb18/showCart.jsp");

}

}

完成以上实验，并提交实验截图