java 读取网络图片的大小（宽+高）

InputStream is = new URL("http://ruanliecache.rydigital.com/rt0/rs640x538/fy/uploads/2013/04/1146.jpg").openStream();                   BufferedImage sourceImg =ImageIO.read(is);   //           // System.out.println(String.format("%.1f",picture.length()/1024.0));              System.out.println(sourceImg.getWidth());              System.out.println(sourceImg.getHeight());