java 读文件大小

public class sss {

 /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub   try {  File f = new File("F://街机//kawaks1.58中文//roms//cps1//1941.zip");

   if (f.exists()) {

  FileInputStream fis = null;

     fis = new FileInputStream(f);

   try {    System.out.println(fis.available());            System.out.println((double)fis.available()/1000/1000);        System.out.println((double)fis.available()/1024/1024);

   } catch (IOException e) {    // TODO Auto-generated catch block    e.printStackTrace();   }     }

      }    catch (FileNotFoundException e) {    // TODO Auto-generated catch block    e.printStackTrace();   } }

}