JSP程序设计 实验指导
import java.io.*; import javax.servlet.*; import javax.servlet.http.*;
public class HandleComputer extends HttpServlet
{ public void init(ServletConfig config) throws ServletException {super.init(config); }
public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { ComputerBean dataBean=null;
HttpSession session=request.getSession(true);
try{ dataBean=(ComputerBean)session.getAttribute(\ if(dataBean==null)
{ dataBean=new ComputerBean(); //创建Javabean对象
session.setAttribute(\将dataBean存储到session对象中 } }
catch(Exception exp)
{ dataBean=new ComputerBean(); //创建Javabean对象
session.setAttribute(\将dataBean存储到session对象中 }
double numberOne=Double.parseDouble(request.getParameter(\ double numberTwo=Double.parseDouble(request.getParameter(\ String operator=request.getParameter(\ double result=0; if(operator.equals(\
{ result=numberOne+numberTwo; }
else if(operator.equals(\
{ result=numberOne-numberTwo; }
else if(operator.equals(\
{ result=numberOne*numberTwo; }
else if(operator.equals(\
{ result=numberOne/numberTwo; }
dataBean.setNumberOne(numberOne); //将数据存储在dataBean中 dataBean.setNumberTwo(numberTwo); //将数据存储在dataBean中 dataBean.setOperator(operator); //将数据存储在dataBean中 dataBean.setResult(result); //将数据存储在dataBean中
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JSP程序设计 实验指导
RequestDispatcher dispatcher= request.getRequestDispatcher(\
dispatcher.forward(request, response);//请求showResult.jsp显示dataBean中的数据 }
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { doPost(request,response); } }
4. 在jsp页面中调用显示javabean属性（结果） showResult.jsp
<%@ page contentType=\<%@ page import=\
3.用户注册验证 <% String username=request.getParameter(\String password=request.getParameter(\String email=request.getParameter(\ 28 JSP程序设计 实验指导 String regex=\正则表达式 boolean flag=email.matches(regex); if(username.length()==0||password.length()==0) out.println(\用户名或密码不能为空！\\n\ else if(!flag) out.println(\邮件地址不合法\ else { //处理表单汉字 byte b[]=username.getBytes(%username=new String(b); b=password.getBytes(\password=new String(b); b=email.getBytes(\email=new String(b); %> <% Connection con; Statement sql; ResultSet rs; try { Class.forName(\ } catch(ClassNotFoundException e) { out.print(\加载数据库驱动失败\ } %> <% String sql1=%username(username,password,email) ('\ con=DriverManager.getConnection(\ sql=con.createStatement(); try{ int m=sql.executeUpdate(sql1); if(m!=0) out.println(\用户名：\密码：\邮箱：\ con.close(); } 29 VALUES JSP程序设计 实验指导 catch(SQLException event){ out.print(\用户名重名。\ }//----else out.println(\返回\out.println(\登陆\ %>
4. 用户登录验证
<%
String username=request.getParameter(\String password=request.getParameter(\
if(username.length()==0||password.length()==0) out.println(\用户名或密码不能为空！\\n\ else {
//处理表单汉字
byte b[]=username.getBytes(%username=new String(b);
b=password.getBytes(\password=new String(b); %>
<% Connection con; Statement sql; ResultSet rs;
try { Class.forName(\ }
catch(ClassNotFoundException e) { out.print(\加载数据库驱动失败\ } %> <%
con=DriverManager.getConnection(\ sql=con.createStatement();
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JSP程序设计 实验指导
try{
rs=sql.executeQuery(\* from username where username='\password='\ if(rs.next())
{ session.setAttribute(\ response.sendRedirect(\ } else
out.print(\用户名或者密码不正确。\\n\ out.println(\返回\ con.close();
}
catch(SQLException event){ out.print(event); } }//----else %>
5. 用户登录成功页面 <%
String user=(String)session.getAttribute(\if(user==null)
{ out.print(\亲，欢迎来到巢湖学院跳蚤网。\ 请登录 免费注册 <%} else
{ out.print(user+\，欢迎来到巢湖学院跳蚤网。\ 退出系统 <%}%>
6. 用户退出页面
<%@ page contentType=\ session.removeAttribute(\response.sendRedirect(\%>
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