jsp登陆验证，网页登陆验证带验证码校验，登录功能之添加验证码
part_1:专门用于生成一个验证码图片的类:VerificationCode.java
package cn.mike.javase.test;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;
import org.junit.Test;
/** * @author : Administrator * @function : 这是用来测试随机生成验证码图片的类； */ public class VerificationCode {
/** * 单元测试，试一下能不能自动生成验证码图片 */ // 这个函数是单元测试时使用的，这里private一下外面就调用不到了； /* @Test */ /* public */private void test_fun() {
VerificationCode vc = new VerificationCode();
BufferedImage image = vc.getImage();
try {
// 生成验证码图片，并保存到指定的路径 VerificationCode.output(image, new FileOutputStream(new File( ".\image\vcode_2.jpg")));
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
// 将随机生成的文本内容输出到控制台，用于校验 System.out.println(vc.getText());
}
private int w = 70;
// 宽 private int h = 35;
// 高 private String text;
// 文本内容(验证码字符串) private Random r = new Random();
private String[] fontNames = {
"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312" }
;
// 随机字符集合中不包括0和o，O，1和l，因为这些不易区分 private String codes = "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYXZ";
// 验证码图片的背景色：白色 private Color bgColor = new Color(255, 255, 255);
/** * 返回一个验证码图片buffer对象：BufferedImage */ public BufferedImage getImage() {
BufferedImage image = createImage();
// 获取绘图环境（画笔工具） Graphics2D g2 = (Graphics2D) image.getGraphics();
// sb ： 用来保存验证码字符串文本内容 StringBuilder sb = new StringBuilder();
for (int i = 0;
i < 4;
++i) {
// 随机生成4个字符 String s = randomChar() + "";
sb.append(s);
float x = i * 1.0F * w / 4;
g2.setFont(randomFont());
g2.setColor(randomColor());
g2.drawString(s, x, h - 5);
}
this.text = sb.toString();
// 记录验证码文本内容 drawLine(image);
// 画干扰线 return image;
}
/** * @return 获取验证码文本内容 */ public String getText() {
return text;
}
/** * @param image * @param out * 将文本写到指定的输出流。比如本测试中FileOutputStream指定的保存路径 */ public static void output(BufferedImage image, OutputStream out) {
try {
ImageIO.write(image, "jpeg", out);
}
catch (IOException e) {
e.printStackTrace();
}
}
private void drawLine(BufferedImage image) {
Graphics2D g2 = (Graphics2D) image.getGraphics();
for (int i = 0;
i < 3;
++i) {
// 画3条干扰线 int x1 = r.nextInt(w);
int y1 = r.nextInt(h);
int x2 = r.nextInt(w);
int y2 = r.nextInt(h);
g2.setColor(Color.BLUE);
g2.drawLine(x1, y1, x2, y2);
}
}
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 Font randomFont() {
int index = r.nextInt(fontNames.length);
String fontName = fontNames[index];
int style = r.nextInt(4);
int size = r.nextInt(5) + 24;
return new Font(fontName, style, size);
}
private char randomChar() {
int index = r.nextInt(codes.length());
return codes.charAt(index);
}
private BufferedImage createImage() {
BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = (Graphics2D) image.getGraphics();
g2.setColor(this.bgColor);
g2.fillRect(0, 0, w, h);
return image;
}
}
part_2:登录界面：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> <base href="<%=basePath%>"> <title>My JSP 'Login.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"> --> <script type="text/javascript"> function _change_verity_code() {
var imgElem = document.getElementById("img_src");
//添加一个请求参数a是因为，通常浏览器都有缓存，点击换一张的时候没反应，所以加一个请求参数，获取当前请求时间，可以精确到毫秒，所以每次请求的参数都不同，所以浏览器有缓存也不妨碍； imgElem.src = "/ServletDemoProject/servlet/GetVerificationCodeServlet?a=" + new Date().getTime();
}
</script> </head> <% String fdbkMsg = (String) request.getAttribute("fdbkMsg");
if (null == fdbkMsg) {
fdbkMsg = "";
}
%> <% Boolean logedIn = (Boolean) session.getAttribute("logedIn");
if (null == logedIn) {
logedIn = false;
}
else if (logedIn) {
//如果在本次会话已经登陆，直接重定向到success-page-1 response .sendRedirect("/ServletDemoProject/LOGIN-DEMO/success-page-1.jsp");
}
%> <% String username = "";
Cookie[] cookies = request.getCookies();
if ((null != cookies) && (cookies.length > 0)) {
for (Cookie c : cookies) {
if ("admin".equals(c.getValue())) {
username = "admin";
break;
}
}
}
//end if-condition %> <body> <br> <div align="center"> 请登录: <br> <form action="/ServletDemoProject/servlet/LoginVerificationServlet" method="post"> <div> 用户名： <input type="text" name="username" value="<%=username%>" /> <br> </div> <div> 密 码： <input type="password" name="password" /> <br> </div> <div> 验证码： <input type="text" name="code_text" size="3" /> <img src="/ServletDemoProject/servlet/GetVerificationCodeServlet" id="img_src" /> <a href="javascript：_change_verity_code()">换一张</a> <br> </div> <div> <font color='red'><%=fdbkMsg%></font> <br> </div> <div> <input type="submit" value="提交" /> <br> </div> </form> </div> </body> </html>
part_3:处理登录校验的servlet ：LoginVerificationServlet.java
package cn.mike.servlet.test_1212;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.mike.javase.test.VerificationCode;
public class GetVerificationCodeServlet extends HttpServlet {
private static final long serialVersionUID = -3520994675366100452L;
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 1.新建一个VerificationCode类； VerificationCode vc = new VerificationCode();
// 2.从VerificationCode类中获取BufferedImage对象； BufferedImage bufImage = vc.getImage();
// 3.同时获取验证码中的文本内容，并放到session域中， 用于校验； String code_text = vc.getText();
request.getSession().setAttribute("code_text", code_text);
// 4.将生成的图片输出到客户端浏览器 VerificationCode.output(bufImage, response.getOutputStream());
}
// end method-doGet public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// do same as GET-method : doGet(request, response);
}
// end method-doPost }
part_4:成功登陆后的提示界面1：success-page-1.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> <base href="<%=basePath%>"> <title>My JSP 'success-page-1.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> <% String username = (String) session.getAttribute("username");
if (null == username) {
//如果username为空值，说明不是通过正常渠道来的，转发到Login页面； request.setAttribute("fdbkMsg", "别想走后门进来，赶紧登录！");
request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward( request, response);
}
%> <body> <br> <%=username%>已经成功登陆。 <br> <font>您可以选择浏览：</font> <br> <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">点这儿有精彩.</a> <br> <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">点这儿更精彩.</a> <br /> <a href="/ServletDemoProject/LOGIN-DEMO/success-page-2.jsp">你敢点这儿吗.</a> <br /> </body> </html>
part_5:成功登陆后的提示界面1：success-page-2.jsp
<%@ page language="java" import="java.util.Date" pageEncoding="UTF-8"%> <%@ page language="java" import="java.text.SimpleDateFormat"%> <% 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 'success-page-2.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> <% String username = (String) session.getAttribute("username");
if (null == username) {
request.setAttribute("fdbkMsg", "呵呵嗒，这里是你来的地方吗？快登陆！");
//转发到登录界面: request.getRequestDispatcher("/LOGIN-DEMO/Login.jsp").forward( request, response);
}
SimpleDateFormat sDateFormat = new SimpleDateFormat("a");
Date today = new Date();
String am_pm_str = sDateFormat.format(today);
String am_pm_str_in_chinese = "";
if ("am".equalsIgnoreCase(am_pm_str)) {
am_pm_str_in_chinese = "上午";
}
else am_pm_str_in_chinese = "下午";
// set null;
sDateFormat = null;
today = null;
am_pm_str = null;
%> <body> <br /> <font><b><%=username%><%=am_pm_str_in_chinese%>好，能来到页面2真不简单.</b> </font> </body> </html>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
