SpringBoot实现发送验证码功能

提示：本次内容主要学习如何做一个发送验证码和识别验证码的功能

文章目录

前言

一、图片验证码是什么？

二、使用步骤

1.创建验证码生成

2.生成验证码

总结

前言

提示：本次内容主要学习如何做一个发送验证码和识别验证码的功能

例如：随着现在互联网的不断发展，Web发展可谓是越来越好，但是在这种情况之下，就会出现很多不守规矩的人，可能会利用爬虫来不断地去破解你的用户，此时验证码的作用就发挥出来了，可以有效地阻止一些不法分子来破解你的网站

一、图片验证码是什么？

图片验证码（Captcha）是一种通过生成图片来验证用户身份的技术，用于区分人类用户和自动化程序。其主要目的是防止机器人的恶意访问和攻击，保护网站的安全。

二、使用步骤

1.创建验证码生成

代码如下（示例）：这个代码主要来源于程序员老罗的教程

package com.easybbs.entity.dto;import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;public class CreateImageCode {// 图片的宽度。private int width = 160;// 图片的高度。private int height = 40;// 验证码字符个数private int codeCount = 4;// 验证码干扰线数private int lineCount = 20;// 验证码private String code = null;// 验证码图片Bufferprivate BufferedImage buffImg = null;Random random = new Random();public CreateImageCode() {creatImage();}public CreateImageCode(int width, int height) {this.width = width;this.height = height;creatImage();}public CreateImageCode(int width, int height, int codeCount) {this.width = width;this.height = height;this.codeCount = codeCount;creatImage();}public CreateImageCode(int width, int height, int codeCount, int lineCount) {this.width = width;this.height = height;this.codeCount = codeCount;this.lineCount = lineCount;creatImage();}// 生成图片private void creatImage() {int fontWidth = width / codeCount;// 字体的宽度int fontHeight = height - 5;// 字体的高度int codeY = height - 8;// 图像bufferbuffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);Graphics g = buffImg.getGraphics();//Graphics2D g = buffImg.createGraphics();// 设置背景色g.setColor(getRandColor(200, 250));g.fillRect(0, 0, width, height);// 设置字体//Font font1 = getFont(fontHeight);Font font = new Font("Fixedsys", Font.BOLD, fontHeight);g.setFont(font);// 设置干扰线for (int i = 0; i < lineCount; i++) {int xs = random.nextInt(width);int ys = random.nextInt(height);int xe = xs + random.nextInt(width);int ye = ys + random.nextInt(height);g.setColor(getRandColor(1, 255));g.drawLine(xs, ys, xe, ye);}// 添加噪点float yawpRate = 0.01f;// 噪声率int area = (int) (yawpRate * width * height);for (int i = 0; i < area; i++) {int x = random.nextInt(width);int y = random.nextInt(height);buffImg.setRGB(x, y, random.nextInt(255));}String str1 = randomStr(codeCount);// 得到随机字符this.code = str1;for (int i = 0; i < codeCount; i++) {String strRand = str1.substring(i, i + 1);g.setColor(getRandColor(1, 255));// g.drawString(a,x,y);// a为要画出来的东西，x和y表示要画的东西最左侧字符的基线位于此图形上下文坐标系的 (x, y) 位置处g.drawString(strRand, i * fontWidth + 3, codeY);}}// 得到随机字符private String randomStr(int n) {String str1 = "ABCDEFGHJKMNOPQRSTUVWXYZabcdefghjkmnopqrstuvwxyz234567890";String str2 = "";int len = str1.length() - 1;double r;for (int i = 0; i < n; i++) {r = (Math.random()) * len;str2 = str2 + str1.charAt((int) r);}return str2;}// 得到随机颜色private Color getRandColor(int fc, int bc) {// 给定范围获得随机颜色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);}/*** 产生随机字体*/private Font getFont(int size) {Random random = new Random();Font font[] = new Font[5];font[0] = new Font("Ravie", Font.PLAIN, size);font[1] = new Font("Antique Olive Compact", Font.PLAIN, size);font[2] = new Font("Fixedsys", Font.PLAIN, size);font[3] = new Font("Wide Latin", Font.PLAIN, size);font[4] = new Font("Gill Sans Ultra Bold", Font.PLAIN, size);return font[random.nextInt(5)];}// 扭曲方法private void shear(Graphics g, int w1, int h1, Color color) {shearX(g, w1, h1, color);shearY(g, w1, h1, color);}private void shearX(Graphics g, int w1, int h1, Color color) {int period = random.nextInt(2);boolean borderGap = true;int frames = 1;int phase = random.nextInt(2);for (int i = 0; i < h1; i++) {double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);g.copyArea(0, i, w1, 1, (int) d, 0);if (borderGap) {g.setColor(color);g.drawLine((int) d, i, 0, i);g.drawLine((int) d + w1, i, w1, i);}}}private void shearY(Graphics g, int w1, int h1, Color color) {int period = random.nextInt(40) + 10; // 50;boolean borderGap = true;int frames = 20;int phase = 7;for (int i = 0; i < w1; i++) {double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);g.copyArea(i, 0, 1, h1, 0, (int) d);if (borderGap) {g.setColor(color);g.drawLine(i, (int) d, i, 0);g.drawLine(i, (int) d + h1, i, h1);}}}public void write(OutputStream sos) throws IOException {ImageIO.write(buffImg, "png", sos);sos.close();}public BufferedImage getBuffImg() {return buffImg;}public String getCode() {return code.toLowerCase();}
}

2.生成验证码

代码如下（示例）：

@RequestMapping("/checkCode")public void checkCode(HttpServletResponse response, HttpSession session) throws IOException {// 创建一个验证码对象，参数分别指定验证码的宽度、高度、字符数量和干扰线数量。CreateImageCode vCode = new CreateImageCode(130, 38, 5, 10);// 设置响应头，确保浏览器不缓存验证码图像。response.setHeader("Pragma","no-cache");response.setHeader("Cache-Control","no-cache");response.setDateHeader("Expires", 0);// 设置响应类型为JPEG图像。response.setContentType("image/jpeg");// 生成验证码字符串。String code = vCode.getCode();// 根据类型将验证码存储在不同的session属性中。session.setAttribute("checkCodeKey",code);// 将生成的验证码图像写入响应输出流。vCode.write(response.getOutputStream());}

具体识别的时候可以从session里面取到，具体情况具体对待吧