自定义验证码 kaptcha

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
            <version>2.6.0</version>
        </dependency>

        <dependency>
            <groupId>com.github.penggle</groupId>
            <artifactId>kaptcha</artifactId>
            <version>2.3.2</version>
        </dependency>

　　

package org.example.captcha;

import javax.servlet.http.HttpServletRequest;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * @author banjuan
 * @date 2021/11/30 2:48 下午
 */
public class CodeUtil {

    /**
     * 将获取到的前端参数转为string类型
     * @param request
     * @param key
     * @return
     */
    public static String getString(HttpServletRequest request, String key) {
        try {
            String result = request.getParameter(key);
            if(result != null) {
                result = result.trim();
            }
            if("".equals(result)) {
                result = null;
            }
            return result;
        }catch(Exception e) {
            return null;
        }
    }

    /**
     * 验证码校验
     * @param request
     * @return
     */
    public static boolean checkVerifyCode(HttpServletRequest request) {
        //获取生成的验证码
        String verifyCodeExpected = (String) request.getSession().getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
        //获取用户输入的验证码
        String verifyCodeActual = CodeUtil.getString(request, "verifyCodeActual");
        if (null != verifyCodeActual) {
            verifyCodeActual = verifyCodeActual.toLowerCase();
        }
        if(verifyCodeActual == null ||!verifyCodeActual.equals(verifyCodeExpected)) {
            return false;
        }
        return true;
    }

    /**
     * 宽高可作为参数传入
     */
    private static final int WIDTH = 110;
    private static final int HEIGHT = 40;

    /**
     * 传入BufferedImage对象，并将生成好的验证码保存到BufferedImage中
     * @param bufferedImage
     * @return
     */
    public static String drawRandomText(BufferedImage bufferedImage) {
        Graphics2D graphics = (Graphics2D) bufferedImage.getGraphics();
        // 设置画笔颜色-验证码背景色
        graphics.setColor(Color.WHITE);
        // 填充背景
        graphics.fillRect(0, 0, WIDTH, HEIGHT);
        graphics.setFont(new Font("宋体,楷体,微软雅黑", Font.BOLD, 26));

        // 数字和字母的组合
        String baseNumLetter = "123456789abcdefghijkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ";

        StringBuilder builder = new StringBuilder();
        // 旋转原点的 x 坐标
        int x = 8;
        String ch;
        Random random = new Random();

        for (int i = 0; i < 4; i++) {
            graphics.setColor(getRandomColor());

            //设置字体旋转角度,角度小于30度
            int degree = random.nextInt() % 30;
            int dot = random.nextInt(baseNumLetter.length());

            ch = baseNumLetter.charAt(dot) + "";
            builder.append(ch);

            //正向旋转
            graphics.rotate(degree * Math.PI / 180, x, 24);
            graphics.drawString(ch, x, 24);

            //反向旋转
            graphics.rotate(-degree * Math.PI / 180, x, 24);
            x += 24;
        }

        //画干扰线
        for (int i = 0; i < 6; i++) {
            // 设置随机颜色
            graphics.setColor(getRandomColor());

            // 随机画线
            graphics.drawLine(random.nextInt(WIDTH), random.nextInt(HEIGHT),
                    random.nextInt(WIDTH), random.nextInt(HEIGHT));

        }

        //添加噪点
        for (int i = 0; i < 30; i++) {
            int x1 = random.nextInt(WIDTH);
            int y1 = random.nextInt(HEIGHT);

            graphics.setColor(getRandomColor());
            graphics.fillRect(x1, y1, 2, 2);
        }
        return builder.toString();
    }

    /**
     * 随机取色
     */
    private static Color getRandomColor() {
        Random ran = new Random();
        return new Color(ran.nextInt(256),
                ran.nextInt(256), ran.nextInt(256));

    }


}

　　

package org.example.captcha;

import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.Producer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;
import java.io.IOException;

/**
 * @author banjuan
 * @date 2021/11/30 2:45 下午
 */
@Controller
public class CodeController {
    @Autowired
    private Producer captchaProducer = null;
    @RequestMapping("/kaptcha")
    public void getKaptchaImage(HttpServletRequest request, HttpServletResponse response) throws Exception {
        HttpSession session = request.getSession();
        response.setDateHeader("Expires", 0);
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        response.setHeader("Pragma", "no-cache");
        response.setContentType("image/jpeg");
        //生成验证码
        String capText = captchaProducer.createText();
        session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
        //向客户端写出
        BufferedImage bi = captchaProducer.createImage(capText);
        ServletOutputStream out = response.getOutputStream();
        ImageIO.write(bi, "jpg", out);
        try {
            out.flush();
        } finally {
            out.close();
        }
    }

    @RequestMapping("/verification")
    public void createImageCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        HttpSession session = request.getSession();
        //禁止缓存
        response.setDateHeader("Expires", 0);
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        response.setHeader("Pragma", "no-cache");
        //设置响应格式为png图片
        response.setContentType("image/png");
        // 生成图片验证码
        BufferedImage image = new BufferedImage(110, 40, BufferedImage.TYPE_INT_RGB);
        String randomText = CodeUtil.drawRandomText(image);
        session.setAttribute(Constants.KAPTCHA_SESSION_KEY, randomText.toLowerCase());
        System.out.println("验证码->>>"+randomText);
        ServletOutputStream out = response.getOutputStream();
        ImageIO.write(image, "png", out);
        out.flush();
        out.close();
    }


    @RequestMapping("/hellow")
    public String Hello() {
        return "hello";
    }
}

　　

package org.example.captcha;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;

/**
 * @author banjuan
 * @date 2021/11/30 2:59 下午
 */
@RestController
public class HelloWorld {
    @RequestMapping("/hello")
    public String hello(HttpServletRequest request) {
        if (!CodeUtil.checkVerifyCode(request)) {
            return "验证码有误！";
        } else {
            return "hello,world";
        }
    }
}

　　

package org.example.captcha;

import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Properties;

/**
 * @author banjuan
 * @date 2021/11/30 3:01 下午
 */
@Configuration
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha getDefaultKaptcha(){
//        DefaultKaptcha captchaProducer = new DefaultKaptcha();
//        Properties properties = new Properties();
//        properties.setProperty("kaptcha.border", "no");
//        //properties.setProperty("kaptcha.border.color", "105,179,90");
//        properties.setProperty("kaptcha.textproducer.font.color", "black");
//        properties.setProperty("kaptcha.image.width", "110");
//        properties.setProperty("kaptcha.image.height", "40");
//        properties.setProperty("kaptcha.textproducer.font.size", "24");
//        properties.setProperty("kaptcha.session.key", "code");
//        properties.setProperty("kaptcha.noise.color", "white");
//        properties.setProperty("kaptcha.textproducer.char.space", "4");
//        properties.setProperty("kaptcha.obscurificator.impl", "com.google.code.kaptcha.impl.FishEyeGimpy");
////        properties.setProperty("kaptcha.background.clear.from", "0,255,0");
////        properties.setProperty("kaptcha.background.clear.to", "255,255,0");
//        properties.setProperty("kaptcha.textproducer.char.length", "4");
////        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
//        properties.setProperty("kaptcha.textproducer.font.names", "Algerian");
//        Config config = new Config(properties);
//        captchaProducer.setConfig(config);
//        return captchaProducer;


        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        // 图片边框
        properties.setProperty("kaptcha.border", "no");
        // 边框颜色
        //properties.setProperty("kaptcha.border.color", "105,179,90");
        // 字体颜色
        properties.setProperty("kaptcha.textproducer.font.color", "red");
        // 验证码整体宽度
        properties.setProperty("kaptcha.image.width", "110");
        // 验证码整体高度
        properties.setProperty("kaptcha.image.height", "40");
        // 文字个数
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        // 文字大小
        properties.setProperty("kaptcha.textproducer.font.size","24");
        // 文字随机字体
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
        // 文字距离
        properties.setProperty("kaptcha.textproducer.char.space","4");
        // 干扰线颜色
        properties.setProperty("kaptcha.noise.color","blue");
        // 自定义验证码背景
        //properties.setProperty("kaptcha.background.impl","com.dt.springbootdemo.config.kaptcha.NoKaptchaBackhround");
        Config config=new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;

    }


}

　　

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        function refresh() {
            document.getElementById('captcha_img').src="/verification?"+Math.random();
        }
    </script>
</head>
<body>
<form action="/hello" method="post">
    验证码:  <input type="text" placeholder="请输入验证码" name="verifyCodeActual">
    <div class="item-input">
        <img id="captcha_img" alt="点击更换" title="点击更换"
             onclick="refresh()" src="/verification" />
    </div>
    <input type="submit" value="提交" />
</form>

</body>
</html>