图片生成缩略图

package com;  
 
import java.io.FileOutputStream;  
 
 
 
public class ToImg {  
    public static void main(String[] args) throws Exception {  
        toSmaillImg("c:/content_bg.jpg","c:/2.jpg");  
    }  
      
    public static void toSmaillImg(String filePath,String thumbPath) throws Exception{  
        String newurl =thumbPath;  
        java.awt.Image bigJpg = javax.imageio.ImageIO.read(new java.io.File(filePath));  
        float tagsize = 100;  
        int old_w = bigJpg.getWidth(null);  
        int old_h = bigJpg.getHeight(null);     
        int new_w = 0;  
        int new_h = 0;  
        float tempdouble;   
        tempdouble = old_w > old_h ? old_w/tagsize : old_h/tagsize;  
        new_w = Math.round(old_w/tempdouble);  
        new_h = Math.round(old_h/tempdouble);  
        java.awt.image.BufferedImage tag = new java.awt.image.BufferedImage(new_w,new_h,java.awt.image.BufferedImage.TYPE_INT_RGB);  
        tag.getGraphics().drawImage(bigJpg,0,0,new_w,new_h,null);  
        FileOutputStream newimage = new FileOutputStream(newurl);  
        com.sun.image.codec.jpeg.JPEGImageEncoder encoder = com.sun.image.codec.jpeg.JPEGCodec.createJPEGEncoder(newimage);         
        encoder.encode(tag);  
        newimage.close();  
    }  
}