Spring实现图片验证码

Spring实现图片验证码

kaptcha

kaptcha是Java中一个生成验证码的第三方库。

结合kaptcha到Web开发中，可以实现生成验证码并保存为图片格式。

引入依赖

implementation 'com.github.penggle:kaptcha:2.3.2'

配置类

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

import java.util.Properties;

@Component
public class KaptchaConfig {

    @Bean
    public DefaultKaptcha getDefaultKaptcha() {

        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();

        // 图片边框
        properties.setProperty("kaptcha.border", "yes");
        // 边框颜色
        properties.setProperty("kaptcha.border.color", "105,179,90");
        // 字体颜色
        properties.setProperty("kaptcha.textproducer.font.color", "red");
        // 图片宽
        properties.setProperty("kaptcha.image.width", "110");
        // 图片高
        properties.setProperty("kaptcha.image.height", "40");
        // 字体大小
        properties.setProperty("kaptcha.textproducer.font.size", "30");
        // session key
        properties.setProperty("kaptcha.session.key", "code");
        // 验证码长度
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        // 字体
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
        // 干扰颜色
        properties.setProperty("kaptcha.noise.color", "35,37,38");

        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);

        return defaultKaptcha;
    }
}

实现类

import com.google.code.kaptcha.impl.DefaultKaptcha;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.UUID;

@RestController
@RequestMapping("/captcha")
public class CaptchaController {

    @Autowired 
    private DefaultKaptcha defaultKaptcha;

    /** 获取图片验证码 */
    @PostMapping(value = "/getCaptcha")
    public void getCaptcha(HttpServletResponse httpServletResponse) throws Exception {

        byte[] captchaChallengeAsJpeg = null;
        ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();
        
        try {
            // 生产验证码字符串并将生成的Token保存到返回头
            String createText = defaultKaptcha.createText();
            String captcha_token = UUID.randomUUID().toString();

            /** 
            * Redis存储captcha_token和createText 
            * 为后续校验做准备 
            * 建议键：captcha_token，值：createText 
            * */
            
            httpServletResponse.setHeader("captcha_token", captcha_token);

            // 使用生成的验证码字符串返回一个BufferedImage对象并转为byte写入到byte数组中
            BufferedImage challenge = defaultKaptcha.createImage(createText);
            ImageIO.write(challenge, "jpg", jpegOutputStream);
        } catch (IllegalArgumentException e) {
            httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        // 定义response输出类型为image/jpeg类型，使用response输出流输出图片的byte数组
        captchaChallengeAsJpeg = jpegOutputStream.toByteArray();
        httpServletResponse.setHeader("Cache-Control", "no-store");
        httpServletResponse.setHeader("Pragma", "no-cache");
        httpServletResponse.setDateHeader("Expires", 0);
        httpServletResponse.setContentType("image/jpeg");
        httpServletResponse.setHeader("Cache-Control", "no-store");
        // 暴露captcha_token头，程序请求才能获取到。
        httpServletResponse.setHeader("Access-Control-Expose-Headers", "captcha_token");
        ServletOutputStream responseOutputStream = httpServletResponse.getOutputStream();
        responseOutputStream.write(captchaChallengeAsJpeg);
        responseOutputStream.flush();
        responseOutputStream.close();
    }

    /** Token校验验证码 */
    @PostMapping(value = "/verifyCaptcha")
    public boolean verifyCaptcha(
            @RequestParam String captchaToken, @RequestParam String captchaContent) {

        /** 
        * 获取captchaToken和captchaContent 
        * 对比Redis中的键值数据 
        * 校验验证码合法性 
        * */
        
        return true;
    }
}

效果

图片验证码：

验证码token：