jar包验证码

喜欢ヅ旅行 2022-06-08 00:39 89阅读 0赞

### 1.将 jcaptcha.jar file into the WEB-INF/lib   2.创建ServletDemo4 ###

### package com.lanou3g.test;      import java.io.IOException;   import javax.servlet.ServletException;   import javax.servlet.annotation.WebServlet;   import javax.servlet.http.HttpServlet;   import javax.servlet.http.HttpServletRequest;   import javax.servlet.http.HttpServletResponse;      import cn.dsna.util.images.ValidateCode;      /\*\*    \* Servlet implementation class ServletDemo4    \*/   @WebServlet("/ServletDemo4")   public class ServletDemo4 extends HttpServlet \{          public void doGet(HttpServletRequest request, HttpServletResponse response)               throws ServletException, IOException \{ ###

### //清空浏览器缓存           response.setHeader("param", "no-cache");             response.setHeader("cache-control", "no-cache");             response.setIntHeader("expires", 0);               //生成一个宽为110，高为25，4个数字，5条干扰线的验证码           ValidateCode validateCode = new ValidateCode(110, 25, 4, 5);           validateCode.write(response.getOutputStream());          \}   \}      3.创建Html   <!DOCTYPE html>   <html>   <head>   <meta charset="UTF-8">   <title>Insert title here</title>   <script type="text/javascript">       function changeCode()\{           var img = document.getElementsByTagName("img")\[0\];           img.src = "/webProject/ServletDemo4?time="+new Date().getTime();       \}   </script>   </head>   <body>       <form actioin="\#">              username：<input type="text" name="username"/><br/>              password：<input type="text" name="password"/><br/>              code：<input type="text" name="code"/>           <img src="/webProject/ServletDemo4" οnclick="changeCode()"><a href="javascript:changeCode()">看不清，换一张</a>              <br/>          </form>   </body>   </html>    ###