您的位置：首页 > 其它

输出随机数字验证码图片

2015-09-06 21:18 495 查看

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.io.IOException;

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;

// 输出随机验证码图片

public class RandomPic extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

// 刷新验证码，设置浏览器不需要缓存

response.setHeader("Expires", "-1");

response.setHeader("Cache-Control", "no-cache");

response.setHeader("Pragma", "no-cache");

// 设置图片的宽高

int width = 120;

int height = 25;

// 创建一副内存图像：BufferedImage 最后一个参数为：红绿蓝色素方式

BufferedImage image = new BufferedImage(width, height,

BufferedImage.TYPE_INT_RGB);

// 得到属于该图片的画笔: Graphics

Graphics g = image.getGraphics();

// 画边框

g.setColor(Color.RED);

g.drawRect(0, 0, width, height);

// 填充背景色

g.setColor(Color.YELLOW);

g.fillRect(1, 1, width - 2, height - 2);

// 画10条干扰线

g.setColor(Color.GRAY);

Random r = new Random();

for (int i = 0; i < 10; i++) {

g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width),

r.nextInt(height));

}

// 随机数字

g.setColor(Color.RED);

g.setFont(new Font("宋体", Font.BOLD | Font.ITALIC, 20));

int x = 23; // 初始数字的横坐标

for (int i = 0; i < 4; i++) {

g.drawString(r.nextInt(10) + "", x, 20);

x += 20;

}

// 输出到浏览器的页面上: ImageIO 参数依次为：内存图像，图像格式，输出方式

ImageIO.write(image, "jpg", response.getOutputStream());

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

doGet(request, response);

}

}

// 创建一个login.html

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

<html>

<head>

<title>用户登录</title>

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="this is my page">

<meta http-equiv="content-type" content="text/html; charset=UTF-8">



<script type="text/javascript">

function toRefresh(){

document.location.href="Login.html"

}

</script>

</head>

<body>

<form action="/day06/servlet/ResponseDemo4" method="post">

用户名： <input type="text" name="username"/> <br/><br/>

密码： <input type="password" name="password"/> <br/><br/>

验证码： <input type="text" name="code" size="3"/>

<img src="/day06/servlet/RandomPic"/>

<a href="javascript:toRefresh()">刷新</a><br/><br/>

<input type="submit" value="登录"/>

</form>

</body>

</html>

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航