<%@ 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>登录页面</title> <style> body{font-size:16px;} </style> <script type="text/javascript"> function $(id){ return document.getElementById(id); } function changeCode(){ $("code").src = "ValidateCodeServlet?a="+new Date(); } function mycheck(){ if(form1.userName.value==""){ alert("用户名不能为空，请输入用户名！"); from1.userName.focus(); return; } if(form1.password.value==""){ alert("密码不能为空，请输入密码！"); from1.password.focus(); return; } if(form1.validationCode.value==""){ alert("验证码不能为空，请输入验证码！"); from1.validationCode.focus(); return; } form1.submit1(); } </script> </head> <body> <form action="loginCheck.jsp" name="form1" methed="post"> 用户名：<input type="text" name="userName" size="16"><br> 密 码：<input type="password" name="password" size="16"><br> 验证码：<input type="text" name="validationCode" size="6"> <input type="hidden" name="validationCode1" value="<%=session.getAttribute("Vcode")%>"> <img class="img_code" src="ValidateCodeServlet" id="code"/> <a href="javascript:changeCode()">换一张</a> <br> <input type="submit" name="submit1" value="登录" onClick="mycheck()"> </form> </body> </html>
import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet("/ValidateCodeServlet") public class ValidateCodeServlet extends HttpServlet{ private static final long serialVersionUID = 1L; public ValidateCodeServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 响应头信息 response.setHeader("Pragma", "No-Cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expries", 0); // 随机数生成类 Random random = new Random(); // 定义验证码的位数 int size = 4; // 定义变量保存生成的验证码 String vCode = ""; char c; // 产生验证码 for (int i = 0; i < size; i++) { // 产生一个26以内的随机整数 int number = random.nextInt(26); // 如果生成的是偶数，则随机生成一个数字 if (number % 2 == 0) { c = (char) ('0' + (char) ((int) (Math.random() * 10))); // 如果生成的是奇数，则随机生成一个字母 } else { c = (char) ((char) ((int) (Math.random() * 26)) + 'A'); } vCode = vCode + c; } // 保存生成的5位验证码 request.getSession().setAttribute("vCode", vCode); // 验证码图片的生成 // 定义图片的宽度和高度 int width = (int) Math.ceil(size * 15); int height = 30; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图片的上下文 Graphics gr = image.getGraphics(); // 设定图片背景颜色 gr.setColor(Color.WHITE); gr.fillRect(0, 0, width, height); // 设定图片边框 gr.setColor(Color.GRAY); gr.drawRect(0, 0, width - 1, height - 1); // 画十条干扰线 for (int i = 0; i < 5; i++) { int x1 = random.nextInt(width); int y1 = random.nextInt(height); int x2 = random.nextInt(width); int y2 = random.nextInt(height); gr.setColor(randomColor()); gr.drawLine(x1, y1, x2, y2); } // 设置字体，画验证码 gr.setColor(randomColor()); gr.setFont(randomFont()); gr.drawString(vCode, 10, 22); // 图像生效 gr.dispose(); // 输出到页面 ImageIO.write(image, "JPEG", response.getOutputStream()); } // 生成随机的颜色 private Color randomColor() { int red = r.nextInt(150); int green = r.nextInt(150); int blue = r.nextInt(150); return new Color(red, green, blue); } private String[] fontNames = { "宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312" }; private Random r = new Random(); // 生成随机的字体 private Font randomFont() { int index = r.nextInt(fontNames.length); String fontName = fontNames[index];// 生成随机的字体名称 int style = r.nextInt(4); int size = r.nextInt(3) + 15; // 生成随机字号, 24 ~ 28 return new Font(fontName, style, size); } }
<%@ 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>处理登录页面数据</title> </head> <body> <% request.setCharacterEncoding("UTF-8"); String name=request.getParameter("userName"); String pw=request.getParameter("password"); //if(request.getParameter("validationCode").equals(request.getParameter("validationCode1"))){ if(name.equals("zhang")&&(pw.equals("123456"))){ session.setAttribute("userName",name); response.sendRedirect("main.jsp"); }else{ response.sendRedirect("Login.jsp"); } //}else{ //response.sendRedirect("Login.jsp"); //} %> </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>系统主页面</title> </head> <body> <% String name=(String)session.getAttribute("userName"); %> 您好，<%=name%>欢迎访问！<br> <a href="exit.jsp">[退出系统]</a> </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>退出系统</title> </head> <body> <% session.invalidate();//销毁session response.sendRedirect("Login.jsp"); %> </body> </html>