標籤：web.xml servlet jsp jdbc
涉及下面幾個檔案：
1，登入頁面 login.jsp
2，成功跳轉頁面 success.jsp
3，失敗跳轉頁面 fail.jsp
4，servlet 處理類 LoginTestServlet.java
5，設定檔 web.xml
--------------------------------------------- 依次看代碼 --------------------------------------------
LoginTestServlet.java 內容
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 = "請輸入使用者名稱（不能超過20個字元）";request.setAttribute("message", result);response.sendRedirect("login.jsp");return;} catch (Exception e) {e.printStackTrace();}}if(psw == "" || psw == null || psw.length() > 20){try {result = "請輸入密碼（不能超過20個字元）";request.setAttribute("message", result);response.sendRedirect("login.jsp");return;} catch (Exception e) {e.printStackTrace();}}//登記JDBC驅動程式try {Class.forName("com.mysql.jdbc.Driver");} catch (Exception e) {System.out.print("Class Not Found Exception");}//連結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", "使用者名稱或密碼不匹配。"); 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>使用者登入</title></head><body> <form method="POST" name="frmLogin" action="LoginTestServlet"> <h1 align="center">使用者登入</h1> <center> <table border="1"> <tr> <td>使用者名稱：</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 碼</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="重設" /> </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("請輸入使用者名稱!"); return false ; } if (sPassword ==""){ alert("請輸入密碼!"); return false ; } } </script></body></html>
<%@ 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("性別：A" + sex +"A") ; if (sex.trim().equals("M")) { sex ="男" ; }else{ sex = "女" ; } %> <div align="center"> <%=userName %> 歡迎您，登陸成功！<br /> <font color="blue">登陸使用者資訊：</font> <table border =1 > <tr> <td> 姓名： </td> <td> <%=userName %> </td> </tr> <tr> <td> 年齡： </td> <td> <%=age %> </td> </tr> <tr> <td> 體重： </td> <td> <%=weight %> kg </td> </tr> <tr> <td> 性別： </td> <td> <%=sex %> </td> </tr> </table> <a href="login.jsp">返回</a> </div></body></html>
<%@ 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%>對不起，登陸失敗！<br /> <font color="red">原因： </font><%=msg%><br /> <br /> 5秒後將返回登陸介面。</div><%response.setHeader("Refresh", "5;URL=/webDemo/login.jsp");%></body></html>
mysql資料庫中需要建立資料庫demo，其中建立表userInfo 建立表語句為：
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‘)) ;
需要把串連mysql的jar包放到項目的lib目錄中
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最後 web.xml 內容
<?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>
java jsp+servlet+mysql實現登入網頁設計
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