开源组件—Kaptcha组件（实现验证码）

最新推荐文章于 2025-07-10 12:18:27 发布

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#kaptcha #验证码 #组件

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本文详细介绍了Kaptcha组件的使用步骤，包括下载2.3版本的jar包，将其导入web项目，配置页面(index.jsp)和web.xml，以及一系列的组件详细配置，如图片边框、颜色、字体、干扰元素等，最后启动项目即可实现验证码功能。

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Kaptcha组件的使用步骤：

1、下载Kaptcha-2.3.jar

下载地址：https://mvnrepository.com/artifact/com.google.code.kaptcha/kaptcha/2.3

2、将jar包导入web项目中

3、编写页面（index.jsp）

源代码：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Kaptcha验证码</title>
</head>
<body>
<form action="<%=request.getContextPath()%>/loginServlet" method="post">
	请输入验证码：<input name="piccode"  type="text" />
	<img alt="验证码" src="<%=request.getContextPath()%>/piccode.jpg" /><br />
	<input type="submit" value="登录" />
</form>
</body>
</html>

4、配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>kaptcha</display-name>
  <servlet>
    <servlet-name>kaptcha</servlet-name>
    <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
    <init-param>
		<description>
		   图片边框，合法值：yes，no
		</description>
			   <param-name>kaptcha.border</param-name>
		    <param-value>no</param-value>
	</init-param>
    <init-param>
	   <description>字体颜色，合法值：white,black,blue.等</description>
		<param-name>kaptcha.textproducer.font.color </param-name>
		<param-value>blue</param-value>
	</init-param>

    
  </servlet>
  <servlet>
  	<servlet-name>loginServlet</servlet-name>
  	<servlet-class>login.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>kaptcha</servlet-name>
    <url-pattern>/piccode.jpg</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
  	<servlet-name>loginServlet</servlet-name>
  	<url-pattern>/loginServlet</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

5、Kaptcha组件详细配置：

Kaptcha图片边框配置

<init-param>

<description>

图片边框，合法值：yes，no

</description>

<param-name>kaptcha.border</param-name>

<param-value>yes</param-value>

</init-param>

Kaptcha图片边框颜色

<init-param>

<description>

边框颜色，合法值：white,black,blue.等

</description>

<param-name>Kaptcha.border.color</param-name>

<param-value>black</param-value>

</init-param>

Kaptcha图片边框厚度

<init-param>

<description>

边框厚度，合法值：0

</description>

<param-name>kaptcha.border.thickness</param-name>

<param-value>1</param-value>

</init-param>

Kaptcha图片边框宽度

<init-param>

<description>图片宽度</description>

<param-name>kaptcha.image.width </param-name>

<param-value>200</param-value>

</init-param>

Kaptcha图片边框高度

<init-param>

<description>图片高度</description>

<param-name>kaptcha.image.height </param-name>

<param-value>50</param-value>

</init-param>

Kaptcha图片实现类

<init-param>

<description>图片实现类</description>

<param-name>kaptcha.producer.impl </param-name>

<param-value>com.google.code.kaptcha.impl.DefaultKaptcha</param-value>

</init-param>

Kaptcha文本实现类

<init-param>

<description>文本实现类</description>

<param-name>kaptcha.textproducer.impl </param-name>

<param-value>com.google.code.kaptcha.text.impl.DefaultTextCreator</param-value>

</init-param>

Kaptcha验证码值配置

<init-param>

<description>文本集合，验证码值从此集合中获取</description>

<param-name>kaptcha.textproducer.char.string </param-name>

<param-value>abcde2345678gfynmnpwx</param-value>

</init-param>

Kaptcha验证码字体配置

<init-param>

<description>字体Arial,Courier</description>

<param-name>kaptcha.textproducer.font.names </param-name>

<param-value>Arial,Courier</param-value>

</init-param>

Kaptcha验证码字体大小配置

<init-param>

<description>字体大小40px.</description>

<param-name>kaptcha.textproducer.font.size </param-name>

<param-value>40</param-value>

</init-param>

Kaptcha验证码字体颜色配置

<init-param>

<description>字体颜色，合法值：white,black,blue.等</description>

<param-name>kaptcha.textproducer.font.color </param-name>

<param-value>black</param-value>

</init-param>

Kaptcha验证码文字间隔配置

<init-param>

<description>文字间隔2</description>

<param-name>kaptcha.textproducer.char.space </param-name>

<param-value>2</param-value>

</init-param>

Kaptcha验证码干扰实现类配置

<init-param>

<description>干扰实现类</description>

<param-name>kaptcha.noise.impl </param-name>

<param-value>com.google.code.kaptcha.impl.DefaultNoise</param-value>

</init-param>

Kaptcha验证码干扰颜色配置

<init-param>

<description>干扰颜色，合法值：r,g,b或者white,black,blue</description>

<param-name>kaptcha.noise.color</param-name>

<param-value>black</param-value>

</init-param>

Kaptcha验证码图片样式配置

<init-param>

<description>图片样式：水纹，鱼眼，阴影</description>

<param-name>kaptcha.obscurificator.impl</param-name>

<param-value>com.google.code.kaptchaimpl.WaterPipple</param-value>

</init-param>

Kaptcha验证码背景实现类配置

<init-param>

<description>背景实现类</description>

<param-name>kaptcha.background.impl </param-name>

<param-value>com.google.code.kaptcha.impl.DefaultBackground</param-value>

</init-param>

Kaptcha验证码背景渐-开始颜色配置

<init-param>

<description>背景颜色渐变，开始颜色</description>

<param-name>kaptcha.background.clear.from</param-name>

<param-value>green</param-value>

</init-param>

Kaptcha验证码背景渐-结束颜色配置

<init-param>

<description>背景颜色渐变，结束 </description>

<param-name>kaptcha.background.clear.to</param-name>

<param-value>white</param-value>

</init-param>

Kaptcha验证码文字渲染器配置

<init-param>

<description>文字渲染器</description>

<param-name>kaptcha.word.impl</param-name>

<param-value>com.google.code.kaptcha.text.impl.DefaultWordRenderer</param-value>

</init-param>

Kaptcha验证码在session中存放验证码的key键配置

<init-param>

<description>session中存放验证码的key键</description>

<param-name>kaptcha.session.key</param-name>

<param-value>KAPTCHA_SESSION_KEY</param-value>

</init-param>

6、启动项目