本文是基于Myeclipse与MySQL数据库表格的增删改查后续完善部分功能的升级版
注：新增加内容：
（1）在查看完学生个人信息表后可退出并返回到主表；
（2）增加登录界面（附验证码）
一、新增信息
（1）logoutServlet.java
package com.microsofti.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import day03_inport.StudentDao;
import day03_student.Student;
public class LogoutServlet extends HttpServlet {
private StudentDao dao = new StudentDao();
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
List<Student> list = dao.queryAll();
request.setAttribute("students", list);
//跳转回列表页面
request.getRequestDispatcher("list.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}
(2)UserServlet.java
package com.microsofti.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class UserServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获取表单提交的数据
String uname = request.getParameter("uname");
String upwd = request.getParameter("upwd");
if("lxd".equals(uname) && "123".equals(upwd)) {
//获取是否保存用户名密码
String daylength = request.getParameter("daylength");
if(daylength != null && !daylength.equals("-1")){
//保存
int day = Integer.parseInt(daylength);
Cookie cname = new Cookie("username", uname);
Cookie cpwd = new Cookie("userpwd",upwd);
//设置保存时间
cname.setMaxAge(day*24*3600);
cpwd.setMaxAge(day*24*3600);
//添加到response
response.addCookie(cname);
response.addCookie(cpwd);
}
//将用户名保存在session中
HttpSession session = request.getSession();
session.setAttribute("currName", uname);
//将用户名保存在request中
request.setAttribute("abc", uname);
//登录人数+1
ServletContext sc = this.getServletContext();
Integer count = (Integer)sc.getAttribute("count");
if(count != null){
count++;
}else{
count=1;
}
sc.setAttribute("count",count);
//跳转到成功页面
// response.sendRedirect("success.jsp");
request.getRequestDispatcher("MyJsp.jsp").forward(request, response);
}else{
//跳转到失败页面
response.sendRedirect("inner.jsp");
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}
(3)image.jsp（自动刷新验证码）
<%@ page contentType="image/JPEG"
import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
pageEncoding="GBK"%>
<%!Color getRandColor(int fc, int bc) {//给定范围获得随机颜色
Random random = new Random();
if (fc > 255)
fc = 255;
if (bc > 255)
bc = 255;
int r = fc + random.nextInt(bc - fc);
int g = fc + random.nextInt(bc - fc);
int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}%>
<%
//设置页面不缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
// 在内存中创建图象
int width = 60, height = 20;
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
Graphics g = image.getGraphics();
//生成随机类
Random random = new Random();
// 设定背景色
g.setColor(getRandColor(200, 250));
g.fillRect(0, 0, width, height);
//设定字体
g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160, 200));
for (int i = 0; i < 100; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
// 取随机产生的认证码(4位数字)
String sRand = "";
for (int i = 0; i < 4; i++) {
String rand = String.valueOf(random.nextInt(10));
sRand += rand;
// 将认证码显示到图象中
g.setColor(new Color(20 + random.nextInt(110), 20 + random
.nextInt(110), 20 + random.nextInt(110)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
g.drawString(rand, 13 * i + 6, 16);
}
// 将认证码存入SESSION
session.setAttribute("code", sRand);
// 图象生效
g.dispose();
// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
%>
(4)inner.jsp修改
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
//判断session是否有用户名
String name = (String)session.getAttribute("currName");
if(name == null){
//保存错误信息
request.setAttribute("errmsg", "用户名/密码错误，请重新登录！");
//跳转回登录页面
request.getRequestDispatcher("login.jsp").forward(request, response);
}
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>登录页面失败！</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<div style="color:red;">登录页面失败！</div>
</body>
</html>
（5）index.jsp修改
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
//获取全部cookie
Cookie[] cookies = request.getCookies();
String name = null,pwd = null;
//遍历
for(Cookie c : cookies){
if(c.getName().equals("username")){
//获取用户名
name = c.getValue();
}
if(c.getName().equals("userpwd")){
//获取密码
pwd = c.getValue();
}
}
if(name != null && pwd != null){
//登录
request.getRequestDispatcher("myservlet?uname="+name+"&upwd="+pwd).forward(request, response);
}
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
This is my JSP page. <br>
</body>
</html>
（6）login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<script type="text/javascript">
function reImg() {
var img = document.getElementById("Img");
img.src = "image.jsp?code=" + Math.random();
}
</script>
<style>
#main{
width:100%;
height:100%; position:absolute; left:50%; top:50%; margin-left:-150px; margin-top:-100px;
}
</style>
<body>
</head>
<body>
<div id="main">
<span style="font-size: 3em">用户登录/LOGIN</span> <br>
-----------------------------------------------------------
<div style="color:red;">${errmsg }</div>
<form action="UserServlet" method="post">
<table style="padding-left: 1em;">
<tr>
<td>用户名：</td>
<td><input type=text name=uname />
</td>
</tr>
<tr>
<td>密 码：</td>
<td><input type="password" name="upwd" />
</td>
</tr>
<tr>
<td>验证码：</td>
<td><input type="text" name="yanzhengma" /><img border=0
id="Img" src="image.jsp" alt="验证码"><a href="#"
onclick="reImg();">看不清，请点击刷新</a>
</td>
</tr>
</table>
<table style="padding-left: 0.6em">
<tr>
<td><input type=radio name=type value=partment>部门 <input
type=radio name=type value=teacher>教师 <input type=radio
name=type value=student checked>学生 <input type=radio
name=type value=guest>访客</td>
</tr>
<tr>
<td>
保存密码时间：<select name="daylength">
<option value="-1">请选择</option>
<option value="3">3天</option>
<option value="7">7天</option>
<option value="30">30天</option>
</select>
<br><br>
<input type="submit" value="登录" /> <input type="reset"
value="重置" />
</td>
</tr>
</table>
</form></div>
</body>
</html>
(7)MyJsp.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="java.io.*" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h2>查看学生基本情况表</h2>
<a href="Listservlet" >
<button>查看</button>
</a>
</body>
</html>
(8)view.jsp修改
<%@page import="day03_student.Student"%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="day03_inport.StudentDao"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>学生个人信息</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<style type="text/css">
table{
border:1px solid gray;
border-collapse:collapse;
width:50%
}
td{
border:1px solid gray;
}
</style>
</head>
<body>
<h2>学生个人基本信息</h2>
<form action="LogoutServlet" method="post">
<table>
<tr>
<td>编号</td>
<td>学号</td>
<td>姓名</td>
<td>性别</td>
<td>年龄</td>
</tr>
<tr>
<%
Student s=(Student)request.getAttribute("students");
%>
<td><%=s.getId()%></td>
<td><%=s.getStuno()%></td>
<td><%=s.getName()%></td>
<td><%=s.getGender()%></td>
<td><%=s.getAge() %></td>
</tr>
</table><br>
<button type="submit" >退出</button>
</form>
</body>
</html>
二、新增样式：
（1）登录界面
登录失败：
登录成功后的显示：
（2）查看个人信息后退出
点击退出后结果
