Spring Boot集成AJ-Captcha实现滑动验证码功能

import com.ajcaptcha.Captcha;
import com.ajcaptcha.CaptchaFactory;
import com.ajcaptcha.CaptchaServiceException;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
 
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
 
@RestController
public class CaptchaController {
 
    private final CaptchaFactory captchaFactory = new CaptchaFactory();
 
    @GetMapping("/captcha")
    public ResponseEntity<byte[]> getCaptcha(HttpServletResponse response) throws IOException, CaptchaServiceException {
        // 设置响应头，浏览器不要缓存
        response.setHeader("Pragma", "no-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
 
        // 创建一个Captcha对象
        Captcha captcha = captchaFactory.createCaptcha();
 
        // 将图片输出为ByteArrayOutputStream
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        ImageIO.write(captcha.getImage(), "png", outputStream);
 
        // 设置session，存储验证码文本
        request.getSession().setAttribute("captcha", captcha.getChallenge());
 
        // 返回图片的响应实体
        return new ResponseEntity<>(outputStream.toByteArray(), HttpStatus.OK);
    }
}

这段代码演示了如何在Spring Boot应用中创建一个简单的控制器，用于处理获取滑动验证码的请求，并返回验证码图片。它使用了CaptchaFactory来创建Captcha对象，并将验证码文本存储在HTTP会话中。最后，它将验证码图片以二进制数据的形式返回给客户端。