public static void main(String args[]) { try { aServer asr = new aServer(); // file channel. FileInputStream is = new FileInputStream(""); is.read(); FileChannel cha = is.getChannel(); ByteBuffer bf = ByteBuffer.allocate(1024); bf.flip(); cha.read(bf); // Path Paths Path pth = Paths.get("", ""); // Files some static operation. Files.newByteChannel(pth); Files.copy(pth, pth); // file attribute, other different class for dos and posix system. BasicFileAttributes bas = Files.readAttributes(pth, BasicFileAttributes.class); bas.size(); } catch (Exception e) { System.err.println(e); } System.out.println("hello "); }