工具類：

package com.util;

import java.awt.Image;  
import java.awt.image.BufferedImage;  
import java.io.File;  
import java.io.IOException;  
  
import javax.imageio.ImageIO;  
  
public class ImageResizer {  
  
    /*** 
     * 功能 :調整圖片大小 開發：wuyechun 2011-7-22 
     * @param srcImgPath 原圖片路徑 
     * @param distImgPath  轉換大小後圖片路徑 
     * @param width   轉換後圖片寬度 
     * @param height  轉換後圖片高度 
     
 
*/  
    public static void resizeImage(String srcImgPath, String distImgPath,  
            int width, int height) throws IOException {  
  
        File srcFile = new File(srcImgPath);  
        Image srcImg = ImageIO.read(srcFile);  
        BufferedImage buffImg = null;  
        buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
        buffImg.getGraphics().drawImage(  
                srcImg.getScaledInstance(width, height, Image.SCALE_SMOOTH), 
 
0,  
                0, null);  
  
        ImageIO.write(buffImg, "JPEG", new File(distImgPath));  
  
    }  
  
}  

調用：

 try {  
                ImageResizer.resizeImage("原路徑","修改後路徑",300,300);  //寬、高
            } catch (IOException e) {  
                System.out.println("圖片轉換出現異常！");  
            }  
 

將圖片轉換大小