jsp作业6
1.安装MySQL数据库，建立用户表 uid uname upwd 并插入3条数据
2.制作jsp登录页面 login.jsp 提交到dologin.jsp，使用jdbc连数据库，判断输入的用户名密码是否存在
3.如果存在，把用户名保存在SESSION中，跳转到welcome.jsp，welcome.jsp中读取session中的用户名，显示欢迎你xxx
4.若不存在，跳到登录页面。
验证码
<%@ page contentType="image/jpeg" language="java" import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageEncoding="utf-8"%>
<%!
Color getRandColor(int fc,int bc){
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-catch");
response.setDateHeader("Expires",0);
//在内存中创建图象
int width = 60;
int height = 20;
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//创建图象
Graphics g = image.getGraphics();
//生成随机对象
Random random = new Random();
//设置背景色
g.setColor(getRandColor(200,250));
g.fillRect(0,0,width,height);
//设置字体
g.setFont(new Font("Tines Nev Roman",Font.PLAIN,18));
//随机产生干扰线
g.setColor(getRandColor(160,200));
for(int i = 0; i < 255; i++){
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
}
//随机产生认证码,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)));
g.drawString(rand,13*i+6,16);
}
session.setAttribute("rCode",sRand);
//图像生效
g.dispose();
//输出图像到页面
ImageIO.write(image,"JPEG",response.getOutputStream());
out.clear();
out = pageContext.pushBody();
%>
数据库
<%@page import="java.nio.channels.SeekableByteChannel"%>
<%@ page language="java" contentType="text/html" pageEncoding="UTF-8"%>
<%@ page import="java.sql.*"%>
<html>
<head>
<title>www.school.com</title>
</head>
<body>
<%!public static final String DBDRIVER = "com.mysql.jdbc.Driver";
public static final String DBURL = "jdbc:mysql://localhost:3306/mysql";
public static final String DBUSER = "root";
public static final String DBPASS = "root";%>
<%
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
boolean flag = false;
String name = null;
%>
<%
try {
Class.forName(DBDRIVER);
conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);
String sql = "SELECT name FROM userr WHERE userid=? AND password=?";
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, request.getParameter("id"));
pstmt.setString(2, request.getParameter("password"));
rs = pstmt.executeQuery();
if (rs.next()) {
name = rs.getString(1);
flag = true;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (rs != null)
rs.close();
if (pstmt != null)
pstmt.close();
if (conn != null)
conn.close();
if (flag) {
request.getSession().setAttribute("name",name);
request.getRequestDispatcher("ok.jsp").forward(request,response);
// request.getRequestDispatcher("ok.jsp").forward(request, response);
} else {
response.sendRedirect("no.jsp");
}
} catch (Exception e) {
e.printStackTrace();
}
}
%>
</body>
</html>
登陆
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
</head>
<body>
<%
String name = (String) request.getSession().getAttribute("name");
%>
欢迎<%=name%>登陆
</body>
</html>
<%@ page language="java" contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
</head>
<body>
<h1>登录失败</h1><hr>
<h2>点击重新<a href="login.jsp">登录</a></h2>
</body>
</html>
index
<%@ 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>
</head>
<body>
<form action="MyJsp.jsp" method="post">
用ID：<input type="text" name="id"/><br>
密码：<input type="password" name="password"/><br>
验证码：<img src="number.jsp"/>
<input type="text" name="code"/><br>
<input type="submit" name="login" value="登录"><br>
</form>
</body>
</html>
