图形验证码（基础）
Posted nxzblogs
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了图形验证码（基础）相关的知识，希望对你有一定的参考价值。
一、生成图形验证码
1、根据随机数生成图片
2、将随机数存储到session中
3、将生成的图片写到接口的响应中
基类：
package com.nxz.security.core.validatecode; import lombok.Data; import java.awt.image.BufferedImage; import java.time.LocalDateTime; @Data public class ImageCode { private BufferedImage image; private String code;//随机数 private LocalDateTime expireTime; public ImageCode(BufferedImage image, String code, int expireIn) { this.image = image; this.code = code; this.expireTime = LocalDateTime.now().plusSeconds(expireIn); } public ImageCode(BufferedImage image, String code, LocalDateTime expireTime) { this.image = image; this.code = code; this.expireTime = expireTime; } }
控制层：
package com.nxz.security.core.controller; import com.nxz.security.core.validatecode.ImageCode; import org.springframework.social.connect.web.HttpSessionSessionStrategy; import org.springframework.social.connect.web.SessionStrategy; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.context.request.ServletWebRequest; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.awt.*; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; @RestController public class ValidateCodeController { private static final String SESSION_KEY = "SESSION_KEY_IMAGE_CODE"; private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy(); @GetMapping("/code/image") public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException { //生成图片 ImageCode imageCode = createImageCode(request); //将随机数存到session中 sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode); ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream()); } private ImageCode createImageCode(HttpServletRequest request) { // 在内存中创建图象 int width = 85, height = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图形上下文 Graphics g = image.getGraphics(); // 生成随机类 Random random = new Random(); // 设定背景色 g.setColor(getRandColor(200, 250)); g.fillRect(0, 0, width, height); // 设定字体 g.setFont(new Font("Times New Roman", Font.PLAIN, 18)); // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到 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); } // 取随机产生的认证码(6位数字) String sRand = ""; for (int i = 0; i < 6; i++) { String rand = String.valueOf(random.nextInt(10)); sRand += rand; // 将认证码显示到图象中 g.setColor(new Color(20 + random.nextInt(110), 20 + random .nextInt(110), 20 + random.nextInt(110))); // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 g.drawString(rand, 13 * i + 6, 16); } // 图象生效 g.dispose(); return new ImageCode(image, sRand, 60); } /* * 给定范围获得随机颜色 */ private Color getRandColor(int fc, int bc) { Random random = new Random(); if (fc > 255) fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); } }
页面：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>自定义登录页面</title> </head> <body> <h2>自定义登录页面</h2> <form action="/authentication/form" method="POST"> <table> <tr> <td>用户名：</td> <td><input type="text" name="username"></td> </tr> <tr> <td>密码：</td> <td><input type="password" name="password"></td> </tr> <tr> <td>图形验证码：</td> <td> <input type="text" name="imagecode"> <img src="/code/image" > </td> </tr> <tr> <td colspan="2"> <button type="submit">登录</button> </td> </tr> </table> </form> </body> </html>
效果：
ps：图形验证码的各种参数都可以配置到application.yml中，并且图形验证码生成器可以配置为可配置类，默认实现一种，动态配置覆盖默认配置
以上是关于图形验证码（基础）的主要内容，如果未能解决你的问题，请参考以下文章