SpringBoot + kaptcha 生成、校对 验证码

1.引入 kaptcha 的 Maven 依赖

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

2.KaptchaConfig 配置文件

@Component
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", "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");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);

        return defaultKaptcha;
    }
}

3.用户注册案例验证码验证（userCotroller）

   // 获取图形验证码
@ApiOperation(value = "获取图形验证码", notes = "获取图形验证码")
@RequestMapping("/defaultKaptcha")
public void defaultKaptcha(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse)
        throws Exception {
    byte[] captchaChallengeAsJpeg = null;
    ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();
    try {
        // 生产验证码字符串并保存到session中
        String createText = defaultKaptcha.createText();
        httpServletRequest.getSession().setAttribute("rightCode", createText);
        // 使用生产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");
    ServletOutputStream responseOutputStream = httpServletResponse.getOutputStream();
    responseOutputStream.write(captchaChallengeAsJpeg);
    responseOutputStream.flush();
    responseOutputStream.close();

}        

4.验证码的验证（usercontroller）

// 用户信息注册
@ApiOperation(value = "获取注册信息", notes = "获取注册信息")
@PostMapping(value = "/registerinfo")
@ResponseBody
public Msg register(@RequestBody @Validated({ Insert.class }) User user, BindingResult bindingResult,
        HttpServletRequest request, HttpServletResponse response) {

    if (bindingResult.hasErrors()) {
        return Msg.failure(bindingResult.getFieldError().getDefaultMessage());
    } else {
                    //获取前端发来的验证码
        String tryCode = user.tryCode;
                    //获取生成的验证码
        String rightCode = (String) request.getSession().getAttribute("rightCode");
                    //比较两个验证码
        if (rightCode.equals(tryCode)) {
            try {
                return userSevice.insert(user);
            } catch (Exception e) {
                e.printStackTrace();
                return Msg.failure("注册失败，服务器忙，请稍后重试");
            }
        } else {
            return Msg.failure("验证码错误");
        }
    }

}

5.用户注册页面

        <form class="layui-form" action="" style="padding: 20px;"   lay-filter="addDialogForm">
             <div class="layui-form-item">
            <label class="layui-form-label">用户名</label>
            <div class="layui-input-inline">
                <input type="text" name="uName" style="width:250px;" id="uName" placeholder="请输入用户名" autocomplete="off" class="layui-input">
            </div>
        </div>

        <div class="layui-form-item">
            <label class="layui-form-label">密码</label>
            <div class="layui-input-inline">
                <input type="password" name="uPwd" style="width:250px;" id="uPwd" placeholder="请输入密码" autocomplete="off" class="layui-input">
                </div>
        </div>

        <div class="layui-form-item">
            <label class="layui-form-label">邮箱</label>
            <div class="layui-input-inline">
                <input type="text" name="uEmail" style="width:250px;" id="uEmail" placeholder="请输入邮箱" autocomplete="off" class="layui-input">
                </div>
        </div>

        <div class="layui-form-item">
            <label class="layui-form-label">手机号</label>
            <div class="layui-input-inline">
                <input type="text" name="uTel" id="uTel" style="width:250px;" placeholder="请输入手机号" autocomplete="off" class="layui-input">
                </div>
        </div>

        <div class="layui-form-item">
            <label class="layui-form-label">权限</label>
            <div class="layui-input-block">
                <input type="radio"  name="uRank" id="uRank1" value="管理员" title="管理员" checked>
                <input type="radio" name="uRank" id="uRank2" value="普通用户" title="普通用户">
            </div>
        </div>

            <div>
            <div  style="float:left; margin-right:5px;" >
                <label class="layui-form-label">验证码</label>
                <input type="text" name="tryCode" id="tryCode" style="width:135px;" placeholder="请输入验证码" autocomplete="off" class="layui-input">
           </div>

            <div    style="float:left ">
                <!-- 后面添加参数起到清除缓存作用 -->
                <img alt="验证码"
                onclick="this.src='/defaultKaptcha?d='+new Date()*1"
                src="/defaultKaptcha" />
            </div>
        </div>   

    </form>

6.效果

7.以上参考https://blog.csdn.net/larger5/article/details/79522105