Java高效率压缩压缩，放大图片

package com.myblog.test;


import java.awt.image.BufferedImage;
import java.awt.Image;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class ImageFactory {


public static void main(String[] args) throws IOException{

File file=new File("F:/图片/big1.JPG"); 装载图片

BufferedImage src = javax.imageio.ImageIO.read(file);
double w=src.getWidth();
double h=src.getHeight();
System.out.println("w:"+w);
System.out.println("h:"+h);
System.out.println("w/h:"+w/h); 打印宽高比
int dw=500; 指定压缩大小 w为500
int dh=(int) (500/(w/h));
BufferedImage tag= new BufferedImage(dw,dh,BufferedImage.TYPE_INT_RGB);

tag.getGraphics().drawImage(src.getScaledInstance(dw, dh, Image.SCALE_SMOOTH), 0, 0, null);
FileOutputStream out=new FileOutputStream("F:/图片/big1small.jpg");
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
out.close();
System.out.println("图片转换完成");
}
}