java 图片压缩和分辨率处理

public class ImgUtil {

public void img_change(String url,String name)

{

Tosmallerpic(url,new File(url+name),"_middle",name,160,160,(float)1);

Tosmallerpic(url,new File(url+name),"_small",name,45,45,(float)0.7);

Tosmallerpic(url,new File(url+name),"_smaller",name,116,100,(float)0.7);

}

/**

*

* @param f 图片所在的文件夹路径

* @param filelist 图片路径

* @param ext 扩展名

* @param n 图片名

* @param w 目标宽

* @param h 目标高

* @param per 百分比

*/

public static void Tosmallerpic(String f,File filelist,String ext,String n,int w,int h,float per){

Image src;

try {

src = javax.imageio.ImageIO.read(filelist); //构造Image对象

String img_midname=f+n.substring(0,n.indexOf("."))+ext+".jpg";

BufferedImage tag = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);

//tag.getGraphics().drawImage(src,0,0,new_w,new_h,null); //绘制缩小后的图

tag.getGraphics().drawImage(src.getScaledInstance(w, h, Image.SCALE_SMOOTH), 0,0,null);

ImageIO.write(tag, "jpg", new File(img_midname));

} catch (IOException ex) {

ex.printStackTrace();

}

}

public static void mainX(String args[]){

//String n="0e5465fc-025a-458d-8383-e9ced0c1e728.jpg";

/* String f="C:\\upload\\img\\";

File file=new File(f);

if(file.exists())

{

File[] filelist=file.listFiles();

for(int i=0;i<filelist.length;i++)

{

String n=filelist[i].getName();

Tosmallerpic(f,filelist[i],"_middle",n,160,160,(float)0.7);

}

} */

//toSmallerPic("d:\\123.png", "d:\\123_111.jpg", 320, 170, Positions.TOP_CENTER, 0.8);

}

}