使用jsp网页登陆验证的步骤

使用jsp网页登陆验证的步骤

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路饭。