java图片验证码

jingliankui123

package com.here.web.common;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;public class Image {//验证码图片中可以出现的字符集，可根据需要修改private char mapTable[]={'a','b','c','d','e','h','j','k','m','n','p','q','r','s','t','u','v','w','x','y','z','0','2','3','4','5','6','7','8','9'};public String getCertPic(int width, int height,OutputStream os) {if(width<=0) {width=60;}if(height<=0) {height=20;}BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);//获取图形上下文Graphics g = image.getGraphics();//设定背景颜色g.setColor(new Color(0xDCDCDC));g.fillRect(0, 0, width, height);//画边框g.setColor(Color.black);g.drawRect(0, 0, width-1, height-1);//随机产生的验证码String strEnsure="";//4代表4位验证码，如果要生成等多位的验证码 ，则加大数值for(int i=0; i<4; i++) {strEnsure += mapTable[(int)(mapTable.length*Math.random())];}//将验证码显示在图像中，如果要生成更多位的验证码，增加drawString语句g.setColor(Color.black);g.setFont(new Font("Atlantic Inline", Font.PLAIN,18));String str = strEnsure.substring(0, 1);g.drawString(str, 8, 17); str = strEnsure.substring(1, 2); g.drawString(str, 20, 15); str = strEnsure.substring(2, 3); g.drawString(str, 35, 18); str = strEnsure.substring(3, 4); g.drawString(str, 45, 15); //随机产生10个干扰点  Random random = new Random(); for(int i=0; i<10; i++ ) { int x = random.nextInt(width); int y = random.nextInt(height); g.drawOval(x, y, 1, 1); }//释放图形上下文 g.dispose(); try{ //输出图像到页面 ImageIO.write(image, "JPEG", os); }catch(IOException e) { return ""; }return strEnsure;}}