package com.guanghua.util.tools;import java.awt.*; import java.awt.image.*; import java.util.*; /** * Created by IntelliJ IDEA. * User: zyzhou * Date: 2006-4-26 * Time: 16:14:36 * To change this template use File | Settings | File Templates. */ public class CheckCode { public String sRand=""; 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); } public BufferedImage creatImage(){// 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 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));//画边框 //g.setColor(new Color()); //g.drawRect(0,0,width-1,height-1); // 随机产生155条干扰线,使图象中的认证码不易被其它程序探测到 g.setColor(getRandColor(160,200)); for (int i=0;i<155;i++) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); g.drawLine(x,y,x+xl,y+yl); }// 取随机产生的认证码(4位数字) //String rand = request.getParameter("rand"); //rand = rand.substring(0,rand.indexOf(".")); for (int i=0;i<4;i++){ String rand=String.valueOf(random.nextInt(10)); sRand+=rand; // 将认证码显示到图象中 g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同,可能是因为种子太接近,所以只能直接生成 g.drawString(rand,13*i+6,16); } // 图象生效 g.dispose(); return image; }}
什么原因?
<%
//设置页面不缓存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0); //获取数字
String strRnd = request.getParameter("rnd");
if (strRnd == null) strRnd = "8888"; int width = 40, height = 20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics(); // 设定背景色
g.setColor(Color.white); g.fillRect(0, 0, width, height); //背景图
Toolkit tool = Toolkit.getDefaultToolkit();
Image mBdimg = tool.getImage(request.getRealPath("/") + "AdvanceCode.gif"); //设定字体
g.setColor(Color.black);
g.setFont(new Font("Comic Sans MS", Font.BOLD, 13));
g.drawImage(mBdimg, 0, 0, null, null);
//输入文字 g.drawString(strRnd, 5 , 15);
g.dispose(); //输出
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(response.getOutputStream());
out.clear();
encoder.encode(image);
tool = null;
mBdimg = null;
encoder = null;
image = null;
g = null;
%>
import java.awt.image.*;
import java.util.*;
/**
* Created by IntelliJ IDEA.
* User: zyzhou
* Date: 2006-4-26
* Time: 16:14:36
* To change this template use File | Settings | File Templates.
*/
public class CheckCode {
public String sRand=""; 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);
}
public BufferedImage creatImage(){// 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
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));//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);
// 随机产生155条干扰线,使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160,200));
for (int i=0;i<155;i++)
{
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x,y,x+xl,y+yl);
}// 取随机产生的认证码(4位数字)
//String rand = request.getParameter("rand");
//rand = rand.substring(0,rand.indexOf(".")); for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;
// 将认证码显示到图象中
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同,可能是因为种子太接近,所以只能直接生成
g.drawString(rand,13*i+6,16);
}
// 图象生效
g.dispose();
return image;
}}