Java简易加减乘图像验证码生成

最新推荐文章于 2024-07-02 13:37:29 发布

转载最新推荐文章于 2024-07-02 13:37:29 发布 · 300 阅读

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CC 4.0 BY-SA版权

原文链接：https://my.oschina.net/pvpCC9IFwqz4/blog/727069

文章标签：

#javascript #python #java #ViewUI

本文介绍了一个使用Java实现的验证码生成器，该生成器能够生成包含简单数学运算的验证码图片，并提供了一个示例控制器代码和前端展示页面。文章还展示了如何通过随机颜色、线条干扰等方式提高验证码的安全性。

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Java:TestYanzhengMaActionController.java

package com.suyin.web.front.controller;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
* @author gyx
*/
@Controller
@RequestMapping("/yzm")
public class TestYanzhengMaActionController {
   @RequestMapping("yanzhengma.do")
   public String toProductList(HttpServletRequest request, HttpServletResponse response) {
       return "/front/test/yanzhengma";
   }

   @RequestMapping("/validateCode")
   public void validateCode(HttpServletRequest request, HttpServletResponse response) throws Exception {
       int width = 126;
       int height = 48;
       int fontHeight = 32;

       // 定义图像buffer-画布
       BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
       //创建2D画笔
       Graphics2D g = buffImg.createGraphics();

       // 将图像填充为白色
       g.setColor(Color.WHITE);
       g.fillRect(0, 0, width, height);

       // 创建字体，字体的大小应该根据图片的高度来定。
       Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
       // 设置字体。
       g.setFont(font);

       // 画边框。
       g.setColor(Color.BLACK);
       g.drawRect(0, 0, width - 1, height - 1);

       // 随机产生干扰线
       g.setColor(Color.BLACK);
       Random random = new Random();
       for (int i = 0; i < 20; i++) {
           int x = random.nextInt(width);
           int y = random.nextInt(height);
           int xl = random.nextInt(20);
           int yl = random.nextInt(20);
           g.drawLine(x, y, x + xl, y + yl);
       }

       //randomCode-用于保存随机产生的验证码,即画布上面的图画
       String randomCode = "";
       int validateCode = 0;

       /**
       * 加减数字控制在10以内
       */
       int a = random.nextInt(4) + 5;
       int b = random.nextInt(4);

       //随机加减乘,除法要处理意外，忽略
       int c = random.nextInt(3);
       switch (c) {
       case 0:
           randomCode = a + "加" + b;
           validateCode = a + b;
           break;
       case 1:
           randomCode = a + "减" + b;
           validateCode = a - b;
           break;
       case 2:
           randomCode = a + "乘" + b;
           validateCode = a * b;
           break;
       default:
           break;
       }

       int red = random.nextInt(255);
       int green = random.nextInt(255);
       int blue = random.nextInt(255);

       // 用随机产生的颜色将验证码绘制到图像中。
       g.setColor(new Color(red, green, blue));
       g.drawString(randomCode, 2, 30);

       //保存session,用于登录验证
       request.getSession().setAttribute("validateCode", validateCode);

       // 禁止图像缓存。
       response.setHeader("Pragma", "no-cache");
       response.setHeader("Cache-Control", "no-cache");
       response.setDateHeader("Expires", 0);
       response.setContentType("image/jpeg");

       //将图像输出->流打印
       ServletOutputStream sos = response.getOutputStream();
       ImageIO.write(buffImg, "jpeg", sos);
       sos.close();
   }
}

jsp:yanzhengma.jsp

<%@ page trimDirectiveWhitespaces="true"%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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">
<meta content="IE=edge,chrome=1" />
<title>验证码</title>

<script src="<c:url value="/app/jquery-1.8.2.min.js"></c:url>" type="text/javascript"></script>
<script type="text/javascript">
function createCode(){
var imgSrc = $("#code");
imgSrc.attr("src","validateCode.do?temp=" + Math.floor(Math.random() * ( 10000 + 1)));
}

$(function() {
createCode();
});
</script>
</head>
<body>
<div>
<input name="vericode" type="text" id="validateCode" placeholder="请输入验证码" />
<br/>
<br/>
<img id="code" src="" onclick="createCode();" alt="看不清楚？点击刷新">
<a onclick="createCode();" style="cursor: pointer;">换一张</a>
</div>
</body>
</html>