JSP实训八student（JSP+JavaBean+Servlet实现投票系统）

1、JSP实训八JSP+JavaBean+Servlet实现投票系统一、实训目的：1、掌握MVC模式。2、掌握投票系统的前台和后台的实现。二、实训内容：一实验一：投票系统前台的实现1、 创立工程chapter9-1，编写login.jsp，用于用户投票。访问页面如图1所示：图1、login.jsp页面 2、把数据库驱动程序复制到lib下。3、 编写J，成员属性有：private Integer id;private String content;private Double number;private String title;4、在工程中添加处理汉字的过滤器SetCharacterEncodi

2、ngFilter。5、创立数据库test表ballot: create table test.ballot( id INT not null auto_increment, content VARCHAR(50), number DOUBLE, title VARCHAR(50), primary key (id) );6、编写result.jsp页面，如图2所示：图2、result.jsp页面7、编写，用于数据库连接、访问。private Connection getConnection()Connection con = null;try Class.forName("com.m

3、ysql.jdbc.Driver"); catch (ClassNotFoundException e1) / TODO Auto-generated catch blocke1.printStackTrace();String url = "jdbc:mysql:/localhost/test"try con = DriverManager.getConnection(url,"root","root"); catch (SQLException e) / TODO Auto-generated catch blocke.

4、printStackTrace();return con;/添加投票public boolean updateBallot(Integer id ,Double number)boolean bool = false;Connection con = this.getConnection();trycon.setAutoCommit(false);Statement sm = con.createStatement();String sql = "update ballot set number="+number+" where id="+id;sm.e

5、xecute(sql);con mit();sm.close();con.close();bool = true;catch(SQLException sql)sql.printStackTrace();catch(Exception e)e.printStackTrace();return bool;/查询一条信息public BallotBean queryOneBallot(Integer id)BallotBean bean = new BallotBean();Connection con = this.getConnection();tryStatement sm = con.cr

6、eateStatement();String sql = "select * from ballot where id="+id;ResultSet result = sm.executeQuery(sql);while(result.next()bean.setId(result.getInt("id");bean.setContent(result.getString("content");bean.setNumber(result.getDouble("number");catch(SQLException

7、sql)sql.printStackTrace();catch(Exception e)e.printStackTrace();return bean;public List queryAllBallot()List ballotList = new ArrayList();Connection con = this.getConnection();tryStatement sm = con.createStatement();String sql = "select * from ballot"ResultSet result = sm.executeQuery(sql)

8、;while(result.next()BallotBean bean = new BallotBean();bean.setId(result.getInt("id");bean.setContent(result.getString("content");bean.setNumber(result.getDouble("number");bean.setTitle(result.getString("title");ballotList.add(bean);catch(SQLException sql)sql.

9、printStackTrace();catch(Exception e)e.printStackTrace();return ballotList;8、编写，用于处理用户提交信息。public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException response.setContentType("text/html");/得到前台传来的值String id = request.getParameter("co

10、ntent");List perList = new ArrayList();JdbcDao jdbc = new JdbcDao();ryOneBallot(new Integer(id);double num = bean.getNumber().doubleValue() + 1;boolean bool = jdbc.updateBallot(new Integer(id), num);if(bool)List ballotList = jdbc.queryBallot();/投票的总数量double sum = 0.0;for(int i=0;i<ballotList

11、.size();i+)BallotBean baBean = (BallotBean)ballotList.get(i);sum = sum + baBean.getNumber();/计算投票的百分比for(int i=0;i<ballotList.size();i+)BallotBean baBean = (BallotBean)ballotList.get(i);double pe = (baBean.getNumber().doubleValue() / sum) * 100;long per = (long)(pe * 100 + 0.5);double percent = (

12、double)per / 100;baBean.setNumber(percent);perList.add(baBean);request.setAttribute("perList", perList);request.getRequestDispatcher("/result.jsp").forward(request, response);9、在表ballot中输入3条记录：10、访问，结果如图2所示。二实验二：投票系统后台的实现对侯选人的增加和删除1、编写，用于添加候选人，页面如图3所示：图3、add.jsp页面<form action=

13、"servlet/Add" method="post"> <table> <tr> <td> 添加党员侯选人 </td> </tr> <tr> <td> 输入侯选人姓名： </td> <td> <input type="text" name="content" /> </td> </tr> <tr> <td> <input type=&q

14、uot;submit" value="提交" /> </td> <td> <input type="reset" value="重置" /> </td> </tr> </table> </form>2、 编写，用于查询候选人。页面如图4、如图5所示：图4、页面<% List list = (List)request.getAttribute("list"); %> <form action=&quo

15、t;servlet/Query" method="post"> <table> <tr> <td> 待选标题：<input type="text" name="title" /> </td> <td> <input type="submit" value="查询" /> </td> </tr> </table> </form> <% if(!(

16、list=null) %> <table> <tr> <td> 带选标题 </td> <td> 侯选人 </td> <td> 票数 </td> <td> 操作 </td> </tr> <% for(int i=0;i<list.size();i+) BallotBean bean = (BallotBean)list.get(i); %> <tr> <td> <%=bean.getTitle() %> &

17、lt;/td> <td> <%=bean.getContent() %> </td> <td> <%=bean.getNumber() %> </td> <td> <a href="servlet/Delete?id=<%=bean.getId() %>">删除</a> </td> </tr> <% %> </table> <% %>3、编写servlet：，用于删出候选人。public v

18、oid doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException response.setContentType("text/html");String id = (String)request.getParameter("id");JdbcDao jdbc = new JdbcDao();jdbc.deleteBallot(id);request.getRequestDispatcher("/query

19、.jsp").forward(request, response);4、编写servlet：，用于添加候选人。public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException response.setContentType("text/html");String title = (String)request.getParameter("title");String content =

20、(String)request.getParameter("content");JdbcDao jdbc = new JdbcDao();boolean bool = jdbc.addBallot(title, content);if(bool)request.setAttribute("message", "添加成功");request.getRequestDispatcher("/add.jsp").forward(request, response);5、编写servlet：Q，用于查询候选人。见p224代码9-96、在数据库访问类J中，增加删除和添加候选人的方法：public void deleteBallot(String id)Connection con = this.getConnection();tryStatement sm = con.createStatement();String sql = "delete from ballot where id="+id;sm