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这里使用编码的方式调用kaptcha实现验证码功能

程序运行截图如下：

输入错误后，还是这个界面，但输入正确后：

maven如下：

   
       
    
     4.0.0
        
    
     org.example
        
    
     kaptchaDemo2
        
    
     1.0-SNAPSHOT
        
    
     war
        
            
                 
      
       com.github.penggle
                  
      
       kaptcha
                  
      
       2.3.2
              
         
    
   

程序结构如下：

源码如下：

LoginServlet.java

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 java.io.IOException;@WebServlet(value = "/login")public class LoginServlet extends HttpServlet {    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        this.doPost(request, response);    }    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        String vailCode = request.getSession().getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY).toString().toLowerCase();        String inCode = request.getParameter("inCode").toLowerCase();        if (inCode.equals(vailCode)) {            response.sendRedirect("success.jsp");        } else {            String url = request.getHeader("Referer");            response.sendRedirect(url);        }    }}

MyServlet.java

       
    
     Archetype Created Web Application
    
   

web.xml

       
    
     Archetype Created Web Application
    
   

index.jsp

<%--  Created by IntelliJ IDEA.  User: cff  Date: 2020/2/1  Time: 9:38  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %>            
   
    
    验证码：    
        
        
    换一张
    
    
    
   

success.jsp

<%--  Created by IntelliJ IDEA.  User: cff  Date: 2020/2/1  Time: 9:49  To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %>    
SUCCESS

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