SpringBoot集成Kaptcha验证码的详细过程

<!-- https://mvnrepository.com/artifact/com.github.penggle/kaptcha -->
<dependency>
	<groupId>com.github.penggle</groupId>
	<artifactId>kaptcha</artifactId>
	<version>2.3.2</version>
</dependency>

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;
@Configuration
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha getDefaultKaptcha() {
        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        // 是否有边框
        properties.setProperty("kaptcha.border", "yes");
        // 边框颜色
        properties.setProperty("kaptcha.border.color", "105,179,90");
        // 验证码文本字符颜色
        properties.setProperty("kaptcha.textproducer.font.color", "blue");
        // 验证码图片宽度
        properties.setProperty("kaptcha.image.width", "110");
        // 验证码图片高度
        properties.setProperty("kaptcha.image.height", "40");
        // 验证码文本字符大小
        properties.setProperty("kaptcha.textproducer.font.size", "30");
        // 验证码存储在session中的key
        properties.setProperty("kaptcha.session.key", "code");
        // 验证码文本字符长度
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        // 验证码文本字体样式
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);
        return defaultKaptcha;
    }
}

import com.google.code.kaptcha.impl.DefaultKaptcha;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
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 DefaultKaptcha defaultKaptcha;
    @GetMapping("/captcha")
    public void captcha(HttpServletRequest request, HttpServletResponse response) throws Exception {
        byte[] captchaOutputStream;
        ByteArrayOutputStream imgOutputStream = new ByteArrayOutputStream();
        try {
            // 生成验证码文字
            String verifyCode = defaultKaptcha.createText();
            request.getSession().setAttribute("captcha", verifyCode);
            BufferedImage challenge = defaultKaptcha.createImage(verifyCode);
            ImageIO.write(challenge, "jpg", imgOutputStream);
        } catch (IllegalArgumentException e) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        }
        captchaOutputStream = imgOutputStream.toByteArray();
        response.setHeader("Cache-Control", "no-store");
        response.setHeader("Pragma", "no-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/jpeg");
        ServletOutputStream responseOutputStream = response.getOutputStream();
        responseOutputStream.write(captchaOutputStream);
        responseOutputStream.flush();
        responseOutputStream.close();
    }
}

@PostMapping("/verify")
public String verifyCaptcha(HttpServletRequest request, @RequestParam("captcha") String captcha) {
    String expectedCaptcha = (String) request.getSession().getAttribute("captcha");
    if (captcha.equals(expectedCaptcha)) {
        return "验证码正确";
    } else {
        return "验证码错误";
    }
}

properties.setProperty("kaptcha.noise.impl", "com.google.code.kaptcha.impl.NoNoise");

properties.setProperty("kaptcha.obscurificator.impl", "com.google.code.kaptcha.impl.WaterRipple");

properties.setProperty("kaptcha.textproducer.char.string", "0123456789");

properties.setProperty("kaptcha.textproducer.char.space", "5");

properties.setProperty("kaptcha.background.impl", "com.google.code.kaptcha.impl.DefaultBackground");
properties.setProperty("kaptcha.background.clear.from", "green");
properties.setProperty("kaptcha.background.clear.to", "yellow");

properties.setProperty("kaptcha.obscurificator.impl", "com.google.code.kaptcha.impl.FishEyeGimpy");