java Web認証コード
4740 ワード
web開発では、コードの使い方を検証するためによく使われます。みんなに例を書いてあげます。
注：利用した技術は主にHttpServletです。
jspホームページ：
注：利用した技術は主にHttpServletです。
jspホームページ：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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">
-->
</head><!-- ， -->
<script type="text/javascript">
function toreal(){
document.location.href="index.jsp";
}
</script>
<body>
<form action="" method="post">
<input type="text" name="username"><br/>
<input type="password" name="password"><br/>
<input type="text" name="code">
<img alt=" " src="/java_Code/servlet/code">
<a href="javascript:toreal()"> </a>
<br/>
<input type="submit" value=" "><br/><!-- ， -->
</form>
</body>
</html>
package com.dp.java.code;
import java.awt.Color;
import java.awt.Font;
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 javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
*
*/
public class code extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//
response.setHeader("Expires", "-1");
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "-1");
int height=25;
int width=120;
// BufferedImage
BufferedImage img=new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//
Graphics g=img.getGraphics();
// drawRect 。
g.drawRect(0, 0, width, height);
//
g.setColor(Color.RED);
g.fillRect(1, 1, width-2, height-2);
//
g.setColor(Color.BLACK);
Random r=new Random();
for(int i=0;i<20;i++)
g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width), r.nextInt(height));
//
g.setColor(Color.BLUE);
g.setFont(new Font(" ", Font.BOLD|Font.ITALIC, 20));//BOLD ，ITALIC
int d=15;
for(int j=0;j<4;j++){
g.drawString(r.nextInt(10)+"", d, 20);
d+=20;
}
// web
ImageIO.write(img, "jpg", response.getOutputStream());
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>java_Code</display-name>
<servlet>
<servlet-name>code</servlet-name>
<servlet-class>com.dp.java.code.code</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>code</servlet-name>
<url-pattern>/servlet/code</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>