java jsp+servlet+mysql实现登录网页设计

来源：互联网发布：ipad怎么开淘宝店铺编辑：程序博客网时间：2024/05/16 06:13

涉及下面几个文件：

1，登录页面 login.jsp

2，成功跳转页面 success.jsp

3，失败跳转页面 fail.jsp

4，servlet 处理类 LoginTestServlet.java

5，配置文件 web.xml

--------------------------------------------- 依次看代码 --------------------------------------------

LoginTestServlet.java 内容

package com.test;import java.io.IOException;import java.sql.DriverManager;import java.sql.ResultSet;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;import com.mysql.jdbc.Connection;import com.mysql.jdbc.Statement;/** * Servlet implementation class LoginTestServlet */@WebServlet("/LoginTestServlet")public class LoginTestServlet extends HttpServlet {private static final long serialVersionUID = 1L;           /**     * @see HttpServlet#HttpServlet()     */    public LoginTestServlet() {        super();            }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/heml;charset=gb2312");request.setCharacterEncoding("gb2312");String result = "";String username = request.getParameter("username");String psw = request.getParameter("password");if(username == "" || username == null || username.length()>20){try {result = "请输入用户名（不能超过20个字符）";request.setAttribute("message", result);response.sendRedirect("login.jsp");return;} catch (Exception e) {e.printStackTrace();}}if(psw == "" || psw == null || psw.length() > 20){try {result = "请输入密码（不能超过20个字符）";request.setAttribute("message", result);response.sendRedirect("login.jsp");return;} catch (Exception e) {e.printStackTrace();}}//登记JDBC驱动程序try {Class.forName("com.mysql.jdbc.Driver");} catch (Exception e) {System.out.print("Class Not Found Exception");}//链接URLString url = "jdbc:mysql://localhost:3306/demo";Connection conn = null;Statement stmt = null;ResultSet rs = null;try {conn = (Connection) DriverManager.getConnection(url,"root","root");stmt = (Statement) conn.createStatement();String sql = "select * from userInfo where username='"+username+"' and userpsw= '"+psw+"'";rs = stmt.executeQuery(sql);} catch (Exception e) {e.printStackTrace();}HttpSession session = request.getSession();session.setAttribute("username", username);try {if(rs.next()){    session.setAttribute("age",rs.getString("age")) ;    session.setAttribute("sex",rs.getString("sex")) ;    session.setAttribute("weight",rs.getString("weight")) ;    response.sendRedirect("success.jsp") ;    return;}else{    session.setAttribute("message", "用户名或密码不匹配。");    response.sendRedirect("fail.jsp") ;    return;}} catch (Exception e) {e.printStackTrace();}}}

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>用户登录</title></head><body> <form method="POST" name="frmLogin" action="LoginTestServlet"> <h1 align="center">用户登录</h1> <center> <table border="1"> <tr> <td>用户名：</td> <td>     <input type="text" name="username" value="" size="20" maxlength="20" onfocus="if (this.value=='Your name')  this.value='';" /> </td> </tr> <tr> <td>密  码</td> <td> <input type="password" name="password" value="" size="20" maxlength="20" onfocus="if(this.value=='Your Password') this.value='';"> </td> </tr> <tr> <td> <input type="submit" name="Submit" value=" 提交" onclick="return validateLogin()"> </td> <td>     <input type="reset" name="Reset" value="重置" /> </td> </tr> </table> </center> </form>  <script type="text/javascript">    function validateLogin(){  var sUserName = document.frmLogin.username.value;  var sPassword = document.frmLogin.psssword.value;     if (sUserName ==""){      alert("请输入用户名!");      return false ;     }          if (sPassword ==""){      alert("请输入密码!");      return false ;     } } </script></body></html>

success.jsp 内容

<%@ page language="java" contentType="text/html; charset=UTF-8"    pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%   String userName = (String)session.getAttribute("username") ;   String age = (String)session.getAttribute("age") ;   String weight = (String)session.getAttribute("weight") ;   String sex = (String)session.getAttribute("sex") ;   System.out.println("性别：A" + sex +"A")  ;   if (sex.trim().equals("M")) {    sex ="男" ;   }else{    sex = "女" ;   }  %>  <div align="center">   <%=userName %>   欢迎您，登陆成功！<br />   <font color="blue">登陆用户信息：</font>   <table border =1 >    <tr>     <td> 姓名： </td>     <td>  <%=userName %>  </td>    </tr>    <tr>     <td> 年龄： </td>     <td>  <%=age %>  </td>    </tr>    <tr>     <td> 体重： </td>     <td>  <%=weight %> kg </td>    </tr>    <tr>     <td> 性别： </td>     <td>  <%=sex %>  </td>    </tr>   </table>   <a href="login.jsp">返回</a>  </div></body></html>

fail.jsp 内容

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Insert title here</title></head><body><%String userName = (String) session.getAttribute("username");String msg = (String) session.getAttribute("message");%><div align="center"><%=userName%>对不起，登陆失败！<br /> <font color="red">原因： </font><%=msg%><br /> <br /> 5秒后将返回登陆界面。</div><%response.setHeader("Refresh", "5;URL=/webDemo/login.jsp");%></body></html>

-------------------------------------------------------配置数据库------------------------------------------------------

mysql数据库中需要创建数据库demo，其中创建表userInfo 创建表语句为：
create databasedemo;
use demo
create table userInfo(id int not null primary key,username char(20) not null,userpsw char(20) ,age int ,weight int ,sex enum('M','F')) ;

需要把连接mysql的jar包放到项目的lib目录中

---------------------------------------------华丽的分割线----------------------------------------

最后 web.xml 内容

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns="http://java.sun.com/xml/ns/javaee"xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"id="WebApp_ID" version="3.0"><display-name>webDemo</display-name><welcome-file-list><welcome-file>index.html</welcome-file><welcome-file>index.htm</welcome-file><welcome-file>index.jsp</welcome-file><welcome-file>default.html</welcome-file><welcome-file>default.htm</welcome-file><welcome-file>default.jsp</welcome-file></welcome-file-list>

<servlet><servlet-name>LoginTestServlet</servlet-name><servlet-class>com.test.LoginTestServlet</servlet-class></servlet><servlet-mapping><servlet-name>LoginTestServlet</servlet-name><url-pattern>/loginTestServlet</url-pattern></servlet-mapping></web-app>

6 1