java生成上传图片的缩略图

# public class ToImg {
#     public static void main(String[] args) throws Exception {
#         toSmaillImg("untitled.bmp","thumb.bmp");
#     }
#
#     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();
#     }
# }