kaptcha驗證碼使用方法詳解

更新時間：2018年12月07日 11:22:41 作者：實踐不斷改變思想

這篇文章主要為大家詳細介紹了kaptcha驗證碼的使用方法，具有一定的參考價值，感興趣的小伙伴們可以參考一下

本文為大家分享了kaptcha驗證碼的使用方法，供大家參考，具體內容如下

1.首先在pom.xml文件中導入Maven依賴

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

2.在web.xml文件中配置一個servlet

<servlet>
 <!-- 生成圖片的Servlet -->
 <servlet-name>Kaptcha</servlet-name>
 <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
 <!-- 是否有邊框 -->
 <init-param> 
        <param-name>kaptcha.border</param-name>
 <param-value>no</param-value>
 </init-param>
 <!-- 字體顏色 -->
 <init-param>
   <param-name>kaptcha.textproducer.font.color</param-name>
 <param-value>red</param-value>
 </init-param>
 <!-- 圖片寬度 -->
 <init-param>
 <param-name>kaptcha.image.width</param-name>
 <param-value>135</param-value>
 </init-param>
 <!-- 使用哪些字符生成驗證碼 -->
 <init-param>
 <param-name>kaptcha.textproducer.char.string</param-name>
  <param-value>ACDEFHKPRSTWX345679</param-value>
 </init-param>
 <!-- 圖片高度 -->
 <init-param>
  <param-name>kaptcha.image.height</param-name>
  <param-value>50</param-value>
 </init-param>
 <!-- 字體大小 -->
 <init-param>
  <param-name>kaptcha.textproducer.font.size</param-name>
  <param-value>43</param-value>
 </init-param>
 <!-- 干擾線的顏色 -->
 <init-param>
  <param-name>kaptcha.noise.color</param-name>
  <param-value>black</param-value>
 </init-param>
 <!-- 字符個數(shù) -->
 <init-param>
  <param-name>kaptcha.textproducer.char.length</param-name>
  <param-value>4</param-value>
 </init-param>
 <!-- 使用哪些字體 -->
 <init-param>
  <param-name>kaptcha.textproducer.font.names</param-name>
  <param-value>Arial</param-value>
 </init-param>
 </servlet>
 <!-- 映射的url -->
 <servlet-mapping>
 <servlet-name>Kaptcha</servlet-name>
 <url-pattern>/Kaptcha</url-pattern>
 </servlet-mapping>

3.頁面代碼如下

<div class="item-inner">
 <label for="j_captcha" class="item-title label">驗證碼</label>
 <input id="j_captcha" name="j_captcha" type="text" 
  class="form-control in" placeholder="驗證碼" />
 <div class="item-input">
   <img id="captcha_img" alt="點擊更換" title="點擊更換"
         onclick="changeVerifyCode(this)" src="../Kaptcha" />
 </div>
</div>

向后端提交數(shù)據(jù)

var verifyCodeActual = $('#j_captcha').val();
 if (!verifyCodeActual) {
  $.toast('請輸入驗證碼！');
  return;
 }
 formData.append("verifyCodeActual", verifyCodeActual);

4.js交互

function changeVerifyCode(img) {
 img.src = "../Kaptcha?" + Math.floor(Math.random() * 100);
}

5.后端驗證

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
  || !verifyCodeActual.equalsIgnoreCase(verifyCodeExpected)) {
  return false;
 }
 return true;
 }
}

import javax.servlet.http.HttpServletRequest;

public class HttpServletRequestUtil {
 public static int getInt(HttpServletRequest request, String name) {

 try {
  return Integer.decode(request.getParameter(name));
 } catch (Exception e) {
  return -1;
 }
 }

 public static long getLong(HttpServletRequest request, String name) {

 try {
  return Long.valueOf(request.getParameter(name));
 } catch (Exception e) {
  return -1;
 }
 }

 public static Double getDouble(HttpServletRequest request, String name) {

 try {
  return Double.valueOf(request.getParameter(name));
 } catch (Exception e) {
  return -1d;
 }
 }

 public static Boolean getBoolean(HttpServletRequest request, String name) {

 try {
  return Boolean.valueOf(request.getParameter(name));
 } catch (Exception e) {
  return false;
 }
 }

 public static String getString(HttpServletRequest request, String name) {
 try {
  String result = request.getParameter(name);
  if (result != null) {
  result = result.trim();
  }
  if ("".equals(result))
  result = null;
  return result;
 } catch (Exception e) {
  return null;
 }

 }
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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