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 "); }
public static void main(String[] args) throws IOException { System.out.println("Input Stream:"); long start = System.currentTimeMillis(); Path filename = Paths.get(args[0]); long crcValue = checksumInputStream(filename); long end = System.currentTimeMillis(); System.out.println(Long.toHexString(crcValue)); System.out.println((end - start) + " milliseconds"); System.out.println("Buffered Input Stream:"); start = System.currentTimeMillis(); crcValue = checksumBufferedInputStream(filename); end = System.currentTimeMillis(); System.out.println(Long.toHexString(crcValue)); System.out.println((end - start) + " milliseconds"); System.out.println("Random Access File:"); start = System.currentTimeMillis(); crcValue = checksumRandomAccessFile(filename); end = System.currentTimeMillis(); System.out.println(Long.toHexString(crcValue)); System.out.println((end - start) + " milliseconds"); System.out.println("Mapped File:"); start = System.currentTimeMillis(); crcValue = checksumMappedFile(filename); end = System.currentTimeMillis(); System.out.println(Long.toHexString(crcValue)); System.out.println((end - start) + " milliseconds"); }
public static void main(String args[]) { int count; Path filepath = null; // First, obtain a path to the file. try { filepath = Paths.get("test.txt"); } catch (InvalidPathException e) { System.out.println("Path Error " + e); return; } // Next, obtain a channel to that file within a try-with-resources block. try (SeekableByteChannel fChan = Files.newByteChannel(filepath)) { // Allocate a buffer. ByteBuffer mBuf = ByteBuffer.allocate(128); do { // Read a buffer. count = fChan.read(mBuf); // Stop when end of file is reached. if (count != -1) { // Rewind the buffer so that it can be read. mBuf.rewind(); // Read bytes from the buffer and show // them on the screen as characters. for (int i = 0; i < count; i++) System.out.print((char) mBuf.get()); } } while (count != -1); System.out.println(); } catch (IOException e) { System.out.println("I/O Error " + e); } }