大家好,又见面了,我是你们的朋友全栈君。
kaptcha 是一个非常实用的验证码生成工具。有了它,你可以生成各种样式的验证码,因为它是可配置的。kaptcha工作的原理是调用 com.google.code.kaptcha.servlet.KaptchaServlet,生成一个图片。同时将生成的验证码字符串放到 HttpSession中。
使用kaptcha可以方便的配置:
- 验证码的字体
- 验证码字体的大小
- 验证码字体的字体颜色
- 验证码内容的范围(数字,字母,中文汉字!)
- 验证码图片的大小,边框,边框粗细,边框颜色
- 验证码的干扰线(可以自己继承com.google.code.kaptcha.NoiseProducer写一个自定义的干扰线)
- 验证码的样式(鱼眼样式、3D、普通模糊……当然也可以继承com.google.code.kaptcha.GimpyEngine自定义样式)
……
详细信息请看下面的web.xml文件
下面介绍一下用法:
1.首先去官网下载jar:http://code.google.com/p/kaptcha/
2.建立一个web项目,导入kaptcha-2.3.jar到环境变量中。
3.配置web.xml文件
- <!–Kaptcha 验证码 –><!–
- <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.border.color</param-name>
- <param-value>105,179,90</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.textproducer.font.color</param-name>
- <param-value>red</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.image.width</param-name>
- <param-value>250</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.image.height</param-name>
- <param-value>90</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.textproducer.font.size</param-name>
- <param-value>70</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.session.key</param-name>
- <param-value>code</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.textproducer.char.length</param-name>
- <param-value>4</param-value>
- </init-param>
- <init-param>
- <param-name>kaptcha.textproducer.font.names</param-name>
- <param-value>宋体,楷体,微软雅黑</param-value>
- </init-param>
- </servlet>
- <servlet-mapping>
- <servlet-name>kaptcha</servlet-name>
- <url-pattern>/ClinicCountManager/kaptcha.jpg</url-pattern>
- lt;/servlet-mapping>
jsp 页面使用
- <table>
- <tr>
- <td><img src=“/ClinicCountManager/kaptcha.jpg”></td>
- <td valign=“top”>
- <form method=“POST”>
- <br>sec code:<input type=“text” name=“kaptchafield”><br />
- <input type=“submit” name=“submit”>
- </form>
- </td>
- </tr>
- </table>
- <br /><br /><br /><br />
- <%
- String c = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
- String parm = (String) request.getParameter(“kaptchafield”);
- out.println(“Parameter: “ + parm + ” ? Session Key: “ + c + ” : “);
- if (c != null && parm != null) {
- if (c.equals(parm)) {
- out.println(“<b>true</b>”);
- } else {
- out.println(“<b>false</b>”);
- }
- %>
上面的配置在普通jsp环境下面是有效的,如果在spring mvc环境下,则取不到session值,对于sping mvc环境验证码配置如下:
1.不用在web.xml进行相关配置,在applicationContext.xml中配置
- <bean id=“captchaProducer” class=“com.google.code.kaptcha.impl.DefaultKaptcha”>
- <property name=“config”>
- <bean class=“com.google.code.kaptcha.util.Config”>
- <constructor-arg>
- <props>
- <prop key=“kaptcha.border”>no</prop>
- <prop key=“kaptcha.border.color”>105,179,90</prop>
- <prop key=“kaptcha.textproducer.font.color”>red</prop>
- <prop key=“kaptcha.image.width”>250</prop>
- <prop key=“kaptcha.textproducer.font.size”>90</prop>
- <prop key=“kaptcha.image.height”>90</prop>
- <prop key=“kaptcha.session.key”>code</prop>
- <prop key=“kaptcha.textproducer.char.length”>4</prop>
- <prop key=“kaptcha.textproducer.font.names”>宋体,楷体,微软雅黑</prop>
- </props>
- </constructor-arg>
- </bean>
- </property>
- </bean>
新建生成图片控制类
- import java.awt.image.BufferedImage;
- import javax.imageio.ImageIO;
- import javax.servlet.ServletOutputStream;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.stereotype.Controller;
- import org.springframework.web.bind.annotation.RequestMapping;
- import org.springframework.web.servlet.ModelAndView;
- import com.google.code.kaptcha.Constants;
- import com.google.code.kaptcha.Producer;
- @Controller
- @RequestMapping(“/”)
- public class CaptchaImageCreateController {
- private Producer captchaProducer = null;
- @Autowired
- public void setCaptchaProducer(Producer captchaProducer) {
- this.captchaProducer = captchaProducer;
- }
- @RequestMapping(“/captcha-image”)
- public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
- response.setDateHeader(“Expires”, 0);
- // Set standard HTTP/1.1 no-cache headers.
- response.setHeader(“Cache-Control”, “no-store, no-cache, must-revalidate”);
- // Set IE extended HTTP/1.1 no-cache headers (use addHeader).
- response.addHeader(“Cache-Control”, “post-check=0, pre-check=0”);
- // Set standard HTTP/1.0 no-cache header.
- response.setHeader(“Pragma”, “no-cache”);
- // return a jpeg
- response.setContentType(“image/jpeg”);
- // create the text for the image
- String capText = captchaProducer.createText();
- // store the text in the session
- request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
- // create the image with the text
- BufferedImage bi = captchaProducer.createImage(capText);
- ServletOutputStream out = response.getOutputStream();
- // write the data out
- ImageIO.write(bi, “jpg”, out);
- try {
- out.flush();
- } finally {
- out.close();
- }
- return null;
- }
- }
前台调用方式
- <div class=“chknumber”>
- <label>验证码:
- <input name=“kaptcha” type=“text” id=“kaptcha” maxlength=“4” class=“chknumber_input” />
- </label>
- <img src=“/ClinicCountManager/captcha-image.do” width=“55” height=“20” id=“kaptchaImage” style=“margin-bottom: -3px”/>
- <script type=“text/javascript”>
- $(function(){
- $(‘#kaptchaImage’).click(function () {
//生成验证码 - $(this).hide().attr(‘src’, ‘/ClinicCountManager/captcha-image.do?’ + Math.floor(Math.random()*100) ).fadeIn(); })
- });
- </script>
- </div>
取验证码的方式
- String code = (String)session.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);
如果需要全部数字
- <init-param>
- <param-name>kaptcha.textproducer.char.string</param-name>
- <param-value>0123456789</param-value>
- </init-param>
去掉干扰线
- <init-param>
- <param-name>kaptcha.noise.impl</param-name>
- <param-value>com.google.code.kaptcha.impl.NoNoise </param-value>
- </init-param>
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