netctoss02_登陆页面图片验证码【Servlet+JSP版】

来源：互联网发布：战舰少女知乎编辑：程序博客网时间：2024/05/16 12:10

1.设计分析

2.代码实现

ImageUtil.java

package com.netctoss.util;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;public final class ImageUtil {// 验证码字符集private static final char[] chars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};// 字符数量private static final int SIZE = 4;// 干扰线数量private static final int LINES = 5;// 宽度private static final int WIDTH = 80;// 高度private static final int HEIGHT = 40;// 字体大小private static final int FONT_SIZE = 30;/** * 生成随机验证码及图片 */public static Object[] createImage() {StringBuffer sb = new StringBuffer();// 1.创建空白图片BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);// 2.获取图片画笔Graphics graphic = image.getGraphics();// 3.设置画笔颜色graphic.setColor(Color.LIGHT_GRAY);// 4.绘制矩形背景graphic.fillRect(0, 0, WIDTH, HEIGHT);// 5.画随机字符Random ran = new Random();for (int i = 0; i <SIZE; i++) {// 取随机字符索引int n = ran.nextInt(chars.length);// 设置随机颜色graphic.setColor(getRandomColor());// 设置字体大小graphic.setFont(new Font(null, Font.BOLD + Font.ITALIC, FONT_SIZE));// 画字符graphic.drawString(chars[n] + "", i * WIDTH / SIZE, HEIGHT*2 / 3);// 记录字符sb.append(chars[n]);}// 6.画干扰线for (int i = 0; i < LINES; i++) {// 设置随机颜色graphic.setColor(getRandomColor());// 随机画线graphic.drawLine(ran.nextInt(WIDTH), ran.nextInt(HEIGHT),ran.nextInt(WIDTH), ran.nextInt(HEIGHT));}// 7.返回验证码和图片return new Object[]{sb.toString(), image};}/** * 随机取色 */public static Color getRandomColor() {Random ran = new Random();Color color = new Color(ran.nextInt(256), ran.nextInt(256), ran.nextInt(256));return color;}public static void main(String[] args) throws IOException {Object[] objs = createImage();BufferedImage image = (BufferedImage) objs[1];OutputStream os = new FileOutputStream("d:/1.jpg");ImageIO.write(image, "jpeg", os);os.close();}}

具体应用见：

http://blog.csdn.net/u011637069/article/details/50985669

注意：

点击超链接更换图片时有的浏览器可能无响应，因为有的浏览器如果发现发送的连接地址已经发送过则不再向服务器发送请求，应该做如下修改：

<img src="createImage.do" alt="验证码" title="点击更换"                               onclick="this.src='createImage.do?x='+Math.random();"/>

在请求地址后面加上任意参数即可！

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