java随机产生验证码.doc

package com.cstp.lottery.image;/* * author * * 创建图形验证码 */import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.File;import java.util.Date;import java.util.LinkedList;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.http.HttpServletResponse;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGImageEncoder;public class RandomImage public String sRand = ; public RandomImage() public Color getRandColor(int fc, int bc) /给定范围获得随机颜色 Random random = new Random(); if (fc 255) fc = 255; if (bc 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); /* * 通过文件创建图像 * 格式为jpg类型 */ public void creatImage(String fileName, String content) /在内存中创建图象 int width = 60, height = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); / 获取图形上下文 Graphics2D g = image.createGraphics(); /Graphics g=image.getGraphics(); /生成随机类 Random random = new Random(); / 设定背景色 g.setColor(getRandColor(200, 250); g.fillRect(0, 0, width, height); /设定字体 g.setFont(new Font(Times New Roman, Font.PLAIN, 18); g.setColor(Color.black);/黑色文字 g.drawString(content, 10, 15); g.dispose(); try File f = new File(fileName); if (!f.exists() f.createNewFile(); else Thread.sleep(200); f.delete(); f.createNewFile(); ImageIO.write(image, jpg, f); catch (Exception e) e.printStackTrace(); /* * 创建图像 * 格式为jpg类型 * * param content - String 图片输出内容 * return java.awt.image.BufferedImage * since 2005-7-19 */ public BufferedImage getBufferedImage(String content) int width = 60, height = 20; return getBufferedImage(content, width, height); /* * 创建图像 * 格式为jpg类型 * * param content - String 图片输出内容 * param width - int 图片宽度 * param height - int 图片高度 * return java.awt.image.BufferedImage * since 2005-7-19 */ public BufferedImage getBufferedImage(String content, int width, int height) /在内存中创建图象 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); / 获取图形上下文 Graphics2D g = image.createGraphics(); /Graphics g=image.getGraphics(); /生成随机类 Random random = new Random(); / 设定背景色 g.setColor(getRandColor(200, 250); g.fillRect(0, 0, width, height); /设定字体 g.setFont(new Font(Times New Roman, Font.PLAIN, 18); g.setColor(Color.black);/黑色文字 g.drawString(content, 10, 15); g.dispose(); return image; /* * 将现有BufferedImage融合进Response * * param response - javax.servlet.http.ServletResponse 将使用的response对象 * param img - java.awt.image.BufferedImage * since 2005-7-19 */ public void response(HttpServletResponse response, BufferedImage img) try response.setContentType(image/jpg;charset=GB2312);/设定输出的类型 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream(); encoder.encode(img);/对图片进行输出编码 catch (Exception e) e.printStackTrace(); /* * 返回一个4位的验证码 */ public String getContent() throws InterruptedException String content = ; for (int i = 0; i 4; i+) content += getChar(); Thread.sleep(new Random().nextInt(10) + 10);/休眠以控制字符的重复问题 return content; /* * 获取随机字符 */ public char getChar() Random random = new Random(); char ch = 0; LinkedList ls = new LinkedList(); for (int i = 0; i 10; i+) /0-9 ls.add(String.valueOf(48 + i); for (int i = 0; i 26; i+) /A-Z ls.add(String.valueOf(65 + i); for (int i = 0; i (ls.size() - 1) index = ls.size() - 1; ch = (char) Integer.parseInt(String.valueOf(ls.get(index); return ch; /* * 测试 */ public static void main(String args) throws Exception RandomImage randomI