昨天晚上在csdn见到一位前辈写一个ajax servlet jsp认证,猛然突发奇想,在阅读文章前辈的编码下我亲自感受一下,干了一个验证码生成工具类,以供大伙儿做下参照。

1、加上VeriyCodeUtils类生成验证码图像

package com.servlet; 
import java.awt.Color; 
import java.awt.Font; 
import java.awt.Graphics3D; 
import java.awt.image.BufferedImage; 
import java.io.OutputStream; 
import java.util.Random; 
import javax.imageio.ImageIO; 
/** 
 * 
 * @author hubiao 
 *  验证码生成器 
 * 采用API 
 *  BufferedImage 建立一个图像 
 *  Graphics3D 绘图 
 *   fillRect(x,y,width,height);情况 
 *   font()字体样式 
 *   drawRect();外框 
 *   drawLine();线 
 *   drwaString:图像数据信息 
 *  ImageIO 生成图像 
 */ 
public class VeriyCodeUtils { 
 /** 
  * @param output 储存认证图像的流 
  * @return 验证码 
  */ 
 public static String newVeriyCode(OutputStream output) 
 { 
  int width = 90; 
  int height = 40; 
  int codeCount = 5; 
  char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',  
    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',  
    'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' }; 
  //建立图像目标,八位RGB 
  BufferedImage buffered = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
  //根据Crapahices来绘图图像到BufferedImage中 
  Graphics3D gra = buffered.createGraphics(); 
  //设定背景图片:乳白色 
  gra.setColor(Color.WHITE); 
  gra.fillRect(0, 0, width, height); 
  //设置字体,文字大小依据照片高度决策 
  gra.setFont(new Font("Fixedsys",Font.PLAIN,height-2)); 
  //设定外框:黑色,一厘米 
  gra.setColor(Color.BLACK); 
  gra.drawRect(0, 0, width-1, height-1); 
  //生成10条黑色影响线 
  gra.setColor(Color.BLACK); 
  Random ran = new Random(); 
  for(int i = 0; i < 70;i  ) 
  { 
   int x = ran.nextInt(255); 
   int y = ran.nextInt(255); 
   int x1 = ran.nextInt(255); 
   int y1 = ran.nextInt(255); 
   gra.drawLine(x, y,x x1, y y1);//画平行线 
  } 
  //生成验证码 
  StringBuffer sb = new StringBuffer(); 
  int r = 0,g = 0,b = 0; 
  for(int i = 0; i < codeCount; i  ) 
  { 
   String strRand = String.valueOf(codeSequence[ran.nextInt(codeSequence.length)]); 
   //对每名验证码都生成不一样的色调,提升识别技术难度系数 
   r = ran.nextInt(255); 
   g = ran.nextInt(255); 
   b = ran.nextInt(255); 
   gra.setColor(new Color(r, g, b)); 
   gra.drawString(strRand, (i 1)*13, height-4); 
   sb.append(strRand); 
  } 
  try { 
   ImageIO.write(buffered, "jpeg", output); 
  } catch (Exception e) { 
   throw new RuntimeException(e); 
  } 
  return sb.toString(); 
 } 
} 

2、servlet应用验证码

protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
   throws ServletException, IOException { 
  //严禁图像缓存文件 
  resp.setHeader("Pragma", "no-cache");  
  resp.setHeader("Cache-Control", "no-cache");  
  resp.setDateHeader("Expires", 0);  
  resp.setContentType("image/jpeg"); 
  //生成验证码图像 
  String veriyCode = VeriyCodeUtils.newVeriyCode(resp.getOutputStream()); 
  //将验证码储存到session中 
  HttpSession session = req.getSession(); 
  session.setAttribute("validateCode", veriyCode); 
 } 

3、JSP网页页面应用验证码

</head> 
 <script type="text/javascript"> 
  function createCode() 
  { 
   var t = new Date().getTime();//避免 网页页面缓存文件,使用时间搓 
   var srcImg = document.getElementById("srcImg"); 
   srcImg.src="https:/ImgVeifyWeb/vity.do?" t; 
  } 
 </script> 
 <body> 
 <h1>${requestScope.code}</h1> 
 <img id="srcImg" src="<c:url value="/vity.do"></c:url>" /> #这儿应用立即让img浏览servlet,根据response回应一个图像流 
 <a href="##" rel="external nofollow" id="codeId" onclick="createCode()">换一张</a> 
 <form action="<c:url value="/hello.do"></c:url>" method="post"> 
  <input type="text" name="codeVify"/> 
  <input type="submit" value="递交"/> 
 </form> 
 </body> 

4、校检验证码

protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
   throws ServletException, IOException { 
  HttpSession session = req.getSession(); 
  Object validateCode = session.getAttribute("validateCode"); 
  System.out.println(validateCode); 
  String codeVify = req.getParameter("codeVify"); 
  if(codeVify==null || codeVify.equals("")) 
  { 
   req.setAttribute("code","认证证不可以为空"); 
   req.getRequestDispatcher("/index.jsp").forward(req, resp); 
   return; 
  }else if(!validateCode.toString().equalsIgnoreCase(codeVify)) 
  { 
   req.setAttribute("code","认证证不正确"); 
   req.getRequestDispatcher("/index.jsp").forward(req, resp); 
   return; 
  } 
  System.out.println("下边刚开始 做别的业务流程实际操作...."); 
 } 

校检图以下:

Jsp servlet验证码工具类分享 验证码 servlet jsp JSP编程  第1张

之上便是文中的所有内容,期待对大伙儿的学习培训有一定的协助,也期待大伙儿多多的适用。