jsp登录验证代码

jsp登录验证代码 image.jsp用于生成数字图片 <%@ page contentType="image/jpeg;charset=gb2312" import="java.awt.*, java.awt.image.*,java.util.*,javax.imageio.*" %> <%! 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<155;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=""; String rand=""; for (int i=0;i<4;i++){ 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); } // 图象生效 g.dispose(); // 将认证码存入SESSION session.setAttribute("random",sRand); // 输出图象到页面 ImageIO.write(image, "JPEG", response.getOutputStream()); %> login.jsp用于进入登陆界面: <%@ page contentType="text/html; charset=gb2312" language="java" errorPage="" %> <% String Username=request.getParameter("Username"); String Password=request.getParameter("Password"); String input= request.getParameter("rand"); if (Username!=null && Password!=null) { //把用户名和密码保存在session中 session.setAttribute("user_name",Username); session.setAttribute("pass_word",Password); session.setAttribute("input",input); //验证用户输入的验证码是否正确 if(input.equals(session.getAttribute("random"))) { //如果正确就跳转到check.jsp验证用户名密码 response.sendRedirect("check.jsp"); } else { //验证码不正确 out.print("错误"); // JOptionPane.showMessageDialog(null,"请选择文件～","提示 ",JOptionPane.ERROR_MESSAGE); } } %>

登录
用户名:
密码:
认证码:

check.jsp用于测试是否成功: <%@ page contentType="text/html; charset=gb2312" language="java" errorPage=""%> <%@ page import="java.sql.*" %> <% String rand =(String)session.getAttribute("random"); String input =(String)session.getAttribute("input"); String user_name= (String)session.getAttribute("user_name"); String pass_word= (String)session.getAttribute("pass_word"); %> 系统产生的认证码为: <%= rand %>
您输入的认证码为: <%= input %>
验证码输入相同，认证成功～

您输入的用户名为: <%= session.getAttribute("user_name") %>
密码为: <%= session.getAttribute("pass_word") %>
<% String permit; ResultSet rs=null; String SqlString="select * from UserInfo where username='"+user_name+"'and password='"+pass_word+"'"; try { //设置连接 sqltest.setConnection("com.microsoft.jdbc.sqlserver.SQLServerDriver", "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=university", "admin","123456"); //设置SQL语句 sqltest.setQuerystatement(SqlString); //得到查询结果 rs=sqltest.getResult(); if (rs.next()) { out.print("登陆成功"); //获得用户的权限 permit=rs.getString("permit"); if (permit.equals("1")) { out.println(":你的权限是管理员组"); } else { out.println(":你的权限是用户组"); } } else { out.print("登陆失败,用户名或密码错"); } } catch(SQLException e1) { out.print("SQL异常～"); } %> 连接数据库的Javabean: sqlbean.java package database; import java.sql.*; public class sqlbean { public String query_statement; public ResultSet result=null; public Connection conn; public void setQuerystatement(String query_statement) { this.query_statement=query_statement; } public void setConnection(String driverName ,String jdbcURL, String username,String passwd) throws Exception { Connection conn1; Class.forName(driverName); conn1=DriverManager.getConnection(jdbcURL, username, passwd); conn1.setAutoCommit(false); this.conn = conn1; } public ResultSet getResult() { try { PreparedStatement select_stm=conn.prepareStatement(query_statement, java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY) ; result=select_stm.executeQuery(); } catch(Exception e) { System.out.println(e); } return result; } }