To find the "feeling" about web 2.0

I am looking for the special feeling for the web 2.0. I compared the flickr from yahoo and picasaweb.google.com. The picasaweb should use the ActiveX and this is not comfort for me, but, i found the basic uploader that is a normal web file uploader page. Actually the flickr is more complex for the images dealing, like resize and more functions.

java image shrink code example

import java.io.File;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.awt.image.AffineTransformOp;
import javax.imageio.ImageIO;
import java.awt.geom.AffineTransform;

public class UploadImg{
/*** @param fromdir 图片的原始目录
* @param todir 处理后的图片存放目录
* @param imgfile 原始图片
* @param sysimgfile 处理后的图片文件名前缀
**/
public boolean CreateThumbnail() throws Exception{
//ext是图片的格式 gif JPG 或png
String ext="";
double Ratio=0.0;
File F = new File(fromdir,imgfile);
if (!F.isFile())
throw new Exception(F+" is not image file error in CreateThumbnail!");
//首先判断上传的图片是gif还是JPG ImageIO只能将gif转换为png
if (isJpg(imgfile))
{ext="jpg";}
else
{ext="png"; }
File ThF = new File(todir,sysimgfile+"."+ext);
BufferedImage Bi = ImageIO.read(F);
//假设图片宽 高 最大为120 120
Image Itemp = Bi.getScaledInstance (120,120,Bi.SCALE_SMOOTH);
if ((Bi.getHeight()>120) (Bi.getWidth()>120)){
if (Bi.getHeight()>Bi.getWidth())
Ratio = 120.0/Bi.getHeight();
else
Ratio = 120.0/Bi.getWidth();
}

AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(Ratio, Ratio), null);
Itemp = op.filter(Bi, null);
try {
ImageIO.write((BufferedImage)Itemp, ext, ThF);
}catch (Exception ex) {
throw new Exception(" ImageIo.write error in CreatThum.: "+ex.getMessage());
}
return (true);
}
}

该程序使用了Java 的AWT,在linux下运行可能报错，有两种解决方式：
(1) jdk1.4以前版本：需要安装 XFree86和XFree86-Xvfb ,加入 export DISPLAY=hostdomain:0.0
(2) jdk 1.4以后版本，在执行命令java 加入参数-Djava.awt.headless=true，表示这是一个没有键盘 没有显示器的无头服务器，意称机房托管的服务器。
关于服务器端图形支持，有很多开源包：PJA VNC 或ACME Laboratories 。

================================================
实际上以上的代码在工作中会抛出异常，实际还是使用了drawImage方法