向后端提交数据

var verifyCodeActual = $('#j_captcha').val();

if (!verifyCodeActual) {

$.toast('请输入验证码！');

return;

}

formData.append("verifyCodeActual", verifyCodeActual);

4.js交互

function changeVerifyCode(img) {

img.src = "../Kaptcha?" + Math.floor(Mhttp://ath.random() * 100);

}

5.后端验证

import javax.servlet.http.HttpServletRequest;

public class CodeUtil {

public static boolean checkVerifyCode(HttpServletRequest request) {

String verifyCodeExpected = (String) request.getSession().getAttribute(

com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);

String verifyCodeActual = HttpServletRequestUtil.getString(request,

"verifyCodeActual");

if (verifyCodeActual == null