Kaptcha

Kaptcha，是Google开源的一个可高度配置的实用验证码生成工具。

1.在Springboot中导入：

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

2.添加Kaptcha的配置规则

可用xml也可以Class （此处采用Class配置）

package kid1999.upload.config;

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

import java.util.Properties;

/**
 * @desc:  Kaptcha 配置类
 * @auther: kid1999
 * @date: 2019/12/21 12:19
 **/

@Service
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha getDefaultKaptcha() {
        com.google.code.kaptcha.impl.DefaultKaptcha defaultKaptcha = new com.google.code.kaptcha.impl.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", "120");
        // 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");

        properties.setProperty("kaptcha.noise.color", "35,37,38");

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

        return defaultKaptcha;
    }
}

3.配置验证码的生成和核对

新建一个Controller

package kid1999.upload.controller;

import com.google.code.kaptcha.impl.DefaultKaptcha;
import kid1999.upload.dto.Result;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
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 javax.servlet.http.HttpSession;
import java.awt.image.BufferedImage;

/**
 * @desc:
 * @auther: kid1999
 * @date: 2019/12/21 12:20
 **/
@Slf4j
@Controller
@RequestMapping("/api/kaptcha")
public class KaptchaController {
    @Autowired
    DefaultKaptcha defaultKaptcha;

    /**
     * 生成验证码
     * @throws Exception
     */
    @RequestMapping("/vrifyCode")
    public ModelAndView getKaptchaImage(HttpServletRequest request, HttpServletResponse response) throws Exception {
        log.info("生成验证码");
        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");
        // 获取KAPTCHA验证的随机文本
        String capText = defaultKaptcha.createText();
        // 将生成好的图片放入会话中
        session.setAttribute("vrifyCode", capText);
        // create the image with the text
        BufferedImage bi = defaultKaptcha.createImage(capText);
        ServletOutputStream out = response.getOutputStream();
        ImageIO.write(bi, "jpg", out);
        try {
            out.flush();
        } finally {
            out.close();//关闭
        }
        return null;
    }

    /**
     * 校对验证码
     * @return
     */
    public Result checkVerificationCode(String vrifyCode, HttpServletRequest request) {
        String verificationCodeIn = (String) request.getSession().getAttribute("vrifyCode");
        request.getSession().removeAttribute("vrifyCode");
        if (StringUtils.isEmpty(verificationCodeIn) || !verificationCodeIn.equals(vrifyCode)) {
            return Result.fail(400,"验证码错误，或已失效");
        }
        return Result.success("验证通过");
    }
}

4.前端的配置

此处以登录的验证码为例

<div class="form-group">
    <div class="input-group" style="float: left;width: 195px;">
        <label>验证码: </label>
        <input type="text" name="code" id="code" class="form-control" style="width: 150px" maxlength="5" placeholder="验证码" autocomplete="off">&nbsp;
    </div>
    <img id="captcha-img" style="width: 120px;height: 40px;display: inline-block;float: right"  src="/api/kaptcha/vrifyCode" onclick="this.src='/api/kaptcha/vrifyCode?d='+ new Date()*1" title="看不清？换一张" />
    <div class="clearfix"></div>
</div>

5.核对

在生成验证码图片的时候，已经将验证码写入session中了
所以此时只需要从session中获取code验证回传的code即可

/** 验证码验证
 */
public Boolean checkVerificationCode(String vrifyCode, HttpServletRequest request) {
	String verificationCodeIn = (String) request.getSession().getAttribute("vrifyCode");
	request.getSession().removeAttribute("vrifyCode");
	if (StringUtils.isEmpty(verificationCodeIn) || !verificationCodeIn.equals(vrifyCode)) {
		return false;
	}
	return true;
}