Java笔记-编码方式创建kaptcha验证码

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：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>kaptchaDemo2</artifactId>
    <version>1.0-SNAPSHOT</version>

    <packaging>war</packaging>

    <dependencies>

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

    </dependencies>

</project>

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

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
    <display-name>Archetype Created Web Application</display-name>
</web-app>

web.xml

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
    <display-name>Archetype Created Web Application</display-name>
</web-app>

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" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>

    <title>kaptchaDemo</title>
    <style type="text/css">
        .code_a{
            color: #0000ff;
            font-size: 12px;
            text-decoration: none;
            cursor: pointer;
        }
        #imgCode{
            cursor: pointer;
        }
    </style>
    <script type="text/javascript">
        function changeCode(){
            var imgCode = document.getElementById("imgCode");
            imgCode.src = "kaptcha?"+Math.random();
        }
    </script>
</head>

<body>
<form action="login" method="post">
    <label>验证码：</label>
    <input type="text" id="inCode" name="inCode" />
    <img src="kaptcha" align="center" id="imgCode" οnclick="changeCode()" />
    <a class="code_a" οnclick="changeCode()">换一张</a><br />
    <input type="submit" value="登录"/>
</form>
</body>
</html>

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" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>SUCCESS</h1>
</body>
</html>

IT1995

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Java笔记-编码方式创建kaptcha验证码

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