登录时候输入验证码，验证码图片从服务器获取方法

article/2025/8/28 10:43:59

登录时候输入验证码，验证码图片从服务器获取方法

小验证码图片源码分享：http://pan.baidu.com/s/1skK7jRJ

展示效果：

登录时候输入验证码，验证码图片从服务器获取方法 - wangyue.123.com - moonstak

在这里插入图片描述

jsp页面：

<%@ page language=“java” import=“java.util.*” pageEncoding=“utf-8”%>

My JSP 'index.jsp' starting page 验证码: ![在这里插入图片描述](https://img-blog.csdnimg.cn/20191206111354505.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dhbmd5dWUyM2NvbQ==,size_16,color_FFFFFF,t_70)

${param.result eq 0 ?"验证码填写错误":"验证码填写正确"}

java后台代码：

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

//判断类型是获取验证码图片还是验证提交的验证码
String type = request.getParameter(“type”);
int trueFlag = 0; //代表是否验证通过 1验证码正确 0验证码错误
if(“form”.equals(type)){
String authCode = (String)request.getSession().getAttribute(“authCode”);
String code = request.getParameter(“code”);
if(authCode.equals(code)){
trueFlag = 1;
}else{
trueFlag = 0;
}
}else if(“generateAuthCode”.equals(type)){
response.setHeader(“Pragma”, “No-cache”);
response.setHeader(“Cache-Control”, “no-cache”);
response.setDateHeader(“Expires”, 0L);

  int width = 60; int height = 20;BufferedImage image = new BufferedImage(width, height, 1);Graphics g = image.getGraphics();Random random = new Random();g.setColor(getRandColor(200, 250));g.fillRect(0, 0, width, height);g.setFont(new Font("Times New Roman", 0, 18));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);}String sRand = "";for (int i = 0; i < 4; i++) {String rand = String.valueOf(random.nextInt(10));sRand = sRand + rand;g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));g.drawString(rand, 13 * i + 6, 16);}//将验证码保存服务器session中request.getSession().setAttribute("authCode", sRand);g.dispose();try{//将图片写入输入流ImageIO.write(image, "JPEG", response.getOutputStream());}catch (Exception localException1){}

}
try{
//跳转回页面
response.sendRedirect(request.getContextPath()+"/index.jsp?result="+trueFlag);
}catch(Exception e){

}
}