介紹：近期公司的網站出現了惡意註冊，惡意刷簡訊的惡劣行為，唉，真惡劣，所以完善登入驗證和傳送簡訊驗證的國字號任務祕密開啟

1.相關引數

2.配置web.xml

<!--驗證碼-->
<servlet>
    <servlet-name>kaptcha</servlet-name>
    <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
    <init-param>
        <param-name>kaptcha.border</param-name>
        <param-value>no</param-value>
    </init-param>
    <init-param>
        <param-name>kaptcha.image.width</param-name>
        <param-value>120</param-value>
    </init-param>
    <init-param>
        <param-name>kaptcha.image.height</param-name>
        <param-value>42</param-value>
    </init-param>
    <init-param>
        <param-name>kaptcha.textproducer.font.size</param-name>
        <param-value>32</param-value>
    </init-param>
    <init-param>
        <param-name>kaptcha.textproducer.char.length</param-name>
        <param-value>5</param-value>
    </init-param>
    <init-param>
        <param-name>kaptcha.obscurificator.impl</param-name>
        <param-value>com.google.code.kaptcha.impl.WaterRipple</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>kaptcha</servlet-name>
    <url-pattern>/kaptcha</url-pattern>
</servlet-mapping>

3. 頁面顯示

<li class="proving-li clearfix">
    <input type="text" placeholder="請輸入圖片驗證碼" onkeyup="checkImageCode()"
class="form-control input-lg pull-left" id="imageRandomCode">
    <div class="input-group pull-right">
        <img src="/kaptcha" id="codeImg" onclick="getCode()" width="146" height="46">
    </div>
</li>

4.新增maven依賴

<dependency>
    <groupId>com.google.code.kaptcha</groupId>
    <artifactId>kaptcha</artifactId>
    <version>2.3.2</version>
</dependency>

5.檢查圖片驗證碼的有效性

/**
 * 檢查圖片驗證碼
 * @param request
* @param captcha
* @return
*/
@RequestMapping("/checkCaptcha")
@ResponseBody
public Map<String, Object> checkCaptcha(HttpServletRequest request,
@RequestParam("captcha") String captcha) {
    try {
        //從session當中讀取驗證碼
String kaptchaExpected = (String) request.getSession()
                .getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
        if (captcha.equals(kaptchaExpected)) {
            return this.getResultMap(ResultCode.SUCCESS, "輸入正確", null);
} else {
            return this.getResultMap(ResultCode.FAIL, "檢驗失敗", null);
}
    } catch (Exception e) {
        logger.error("checkCaptcha---error", e);
        return this.getResultMap(ResultCode.ERROR, "系統錯誤", null);
}
}