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();
}
}