Java實現驗證碼功能
阿新 • • 發佈：2019-01-07
package com.suse;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import package com.suse;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginServlet extends HttpServlet {
// doget/dopost方法是根據後面提交方式來實現
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String picode = (String) request.getSession().getAttribute("picode");
String checkcode = request.getParameter("checkcode");
checkcode = checkcode.toUpperCase();
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
if (checkcode.equals(picode)) {
out.print("驗證碼正確");
} else {
out.print("驗證碼輸入錯誤");
}
out.flush();// 輸出流重新整理
out.close();// 關閉輸出流
}
}<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<script type="text/javascript">
//重新獲得驗證碼
function reloadCode(){
var time=new Date().getTime();//由於瀏覽器有快取作用，所以這裡必須設定時間來表式不同時刻的請求
document.getElementById("imgcode").src="<%=request.getContextPath()%>/servlet/ImageServlet?="
+time
}
</script>
</head>
<body>
<form action="<%=request.getContextPath()%>/servlet/LoginServlet" method="post">
驗證碼：<input type="text" name="checkcode" />
<img alt="驗證碼" id="imgcode" src="<%=request.getContextPath()%>/servlet/ImageServlet"/>
<a href="javascript:reloadCode();">看不清楚</a><br>
<input type="submit" value="提交" name="submit"/>
</form>
</body>
</html><?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<display-name></display-name>
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>com.suse.ImageServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.suse.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/servlet/ImageServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/servlet/LoginServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>