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

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、 创建项目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JavaBean:BallotBean.java，成员属性有：private Integer id;private String content;private Double number;private String title;4、在项目中添加处理汉字的过滤器SetCharacterEncodingFilter。5、创建数据库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JdbcDao.java，用于数据库连接、访问。private Connection getConnection()Connection con = null;try Class.forName(com.mysql.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.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.execute(sql);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.createStatement();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 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);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.printStackTrace();catch(Exception e)e.printStackTrace();return ballotList;8、编写servlet:disposal.java，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(content);List perList = new ArrayList();JdbcDao jdbc = new JdbcDao();BallotBean bean = jdbc.queryOneBallot(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;iballotList.size();i+)BallotBean baBean = (BallotBean)ballotList.get(i);sum = sum + baBean.getNumber();/计算投票的百分比for(int i=0;iballotList.size();i+)BallotBean baBean = (BallotBean)ballotList.get(i);double pe = (baBean.getNumber().doubleValue() / sum) * 100;long per = (long)(pe * 100 + 0.5);double percent = (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login.jsp，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add.jsp，用于添加候选人，页面如图3所示：图3、add.jsp页面 添加党员侯选人 输入侯选人姓名： 2、 编写query.jsp，用于查询候选人。页面如图4、如图5所示：图4、query.jsp页面 待选标题： 带选标题 侯选人 票数 操作 % for(int i=0;i a href=servlet/Delete?id=删除 3、编写servlet：Delete.java，用于删出候选人。public void 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.jsp).forward(request, response);4、编写servlet：add.java，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 = (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：Query.java，用于查询候选人。（见p224代码9-9）6、在数据库访问类JdbcDao.java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.execute(sql);/Querycatch(SQLException sql)sql.printStackTrace();catch(Exception e)e.printStackTrace();/向投票表中添加内容public boolean addBallot(String title ,String content ) boolean bool = false;Connection con = this.getConnection();try con.setAutoCommit(false);Statement sm = con.createStatement();String sql = insert into ballot(content,number,title) value(+content+,0.0,+titl