15_Spring Boot集成AJ-Captcha实现滑动验证码功能

import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.Producer;
import com.google.code.kaptcha.util.Config;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
 
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
 
@RestController
public class CaptchaController {
 
    @Autowired
    private Producer kaptchaProducer;
 
    @GetMapping("/captcha")
    public void defaultKaptcha(HttpServletRequest request, HttpServletResponse response) throws Exception {
        byte[] captchaChallengeAsJpeg = null;
        ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();
        try {
            // 获取验证码文本内容
            String captchaText = kaptchaProducer.createText();
            // 生成验证码图片
            BufferedImage challenge = kaptchaProducer.createImage(captchaText);
            ImageIO.write(challenge, "jpg", jpegOutputStream);
 
            // 将验证码文本内容保存到session中
            request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, captchaText);
 
            // 设置响应头
            response.setHeader("Cache-Control", "no-store");
            response.setHeader("Pragma", "no-cache");
            response.setDateHeader("Expires", 0);
            response.setContentType("image/jpeg");
 
            // 将图片输出到客户端
            ServletOutputStream responseOutputStream = response.getOutputStream();
            responseOutputStream.write(jpegOutputStream.toByteArray());
            responseOutputStream.flush();
            responseOutputStream.close();
        } finally {
            if (jpegOutputStream != null) {
                jpegOutputStream.close();
            }
        }
    }
}

这段代码实现了一个简单的滑动验证码接口，当访问 /captcha 路径时，会生成一个新的验证码图片并返回给客户端。验证码文本内容保存在了session中，以供后续的登录或者其他需要验证的操作使用。