List of usage examples for java.io FileInputStream getChannel
public FileChannel getChannel()
From source file:ExplicitChannelRead.java
public static void main(String args[]) { FileInputStream fIn; FileChannel fChan;/*from w ww . j av a 2 s. c o m*/ long fSize; ByteBuffer mBuf; try { fIn = new FileInputStream("test.txt"); fChan = fIn.getChannel(); fSize = fChan.size(); mBuf = ByteBuffer.allocate((int) fSize); fChan.read(mBuf); mBuf.rewind(); for (int i = 0; i < fSize; i++) System.out.print((char) mBuf.get()); fChan.close(); fIn.close(); } catch (IOException exc) { System.out.println(exc); System.exit(1); } }
From source file:MappedChannelRead.java
public static void main(String args[]) { FileInputStream fIn; FileChannel fChan;/*from ww w . j ava 2s . c o m*/ long fSize; MappedByteBuffer mBuf; try { fIn = new FileInputStream("test.txt"); fChan = fIn.getChannel(); fSize = fChan.size(); mBuf = fChan.map(FileChannel.MapMode.READ_ONLY, 0, fSize); for (int i = 0; i < fSize; i++) System.out.print((char) mBuf.get()); fChan.close(); fIn.close(); } catch (IOException exc) { System.out.println(exc); System.exit(1); } }
From source file:MainClass.java
public static void main(String args[]) { FileInputStream fIn; FileChannel fChan;/*w w w . j a v a 2 s. co m*/ long fSize; ByteBuffer mBuf; try { fIn = new FileInputStream("test.txt"); fChan = fIn.getChannel(); fSize = fChan.size(); mBuf = ByteBuffer.allocate((int) fSize); fChan.read(mBuf); mBuf.rewind(); for (int i = 0; i < fSize; i++) System.out.print((char) mBuf.get()); fChan.close(); fIn.close(); } catch (IOException exc) { System.out.println(exc); } }
From source file:Main.java
public static void main(String[] args) throws IOException { int i = 0;/*w w w .j av a 2 s . co m*/ FileInputStream fis = new FileInputStream("C://test.txt"); // read till the end of the file while ((i = fis.read()) != -1) { // get file channel FileChannel fc = fis.getChannel(); // get channel position long pos = fc.position(); char c = (char) i; System.out.println("No of bytes read: " + pos); System.out.println("Char read: " + c); } }
From source file:MainClass.java
public static void main(String args[]) { FileInputStream fileInputStream; FileChannel fileChannel;//from w w w. j av a 2 s.c o m long fileSize; MappedByteBuffer mBuf; try { fileInputStream = new FileInputStream("test.txt"); fileChannel = fileInputStream.getChannel(); fileSize = fileChannel.size(); mBuf = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileSize); for (int i = 0; i < fileSize; i++) System.out.print((char) mBuf.get()); fileChannel.close(); fileInputStream.close(); } catch (IOException exc) { System.out.println(exc); System.exit(1); } }
From source file:MainClass.java
public static void main(String[] a) { File aFile = new File("charData.txt"); FileInputStream inFile = null; try {//from w w w .jav a 2 s . c o m inFile = new FileInputStream(aFile); } catch (FileNotFoundException e) { e.printStackTrace(System.err); System.exit(1); } FileChannel inChannel = inFile.getChannel(); }
From source file:MainClass.java
public static void main(String[] args) { File aFile = new File("C:/test.bin"); FileInputStream inFile = null; try {//from ww w.ja v a 2 s . c o m inFile = new FileInputStream(aFile); } catch (FileNotFoundException e) { e.printStackTrace(System.err); } FileChannel inChannel = inFile.getChannel(); final int PRIMECOUNT = 6; ByteBuffer buf = ByteBuffer.allocate(8 * PRIMECOUNT); long[] primes = new long[PRIMECOUNT]; try { while (inChannel.read(buf) != -1) { ((ByteBuffer) (buf.flip())).asLongBuffer().get(primes); for (long prime : primes) { System.out.printf("%10d", prime); } buf.clear(); } inFile.close(); } catch (IOException e) { e.printStackTrace(System.err); } }
From source file:BGrep.java
public static void main(String[] args) { String encodingName = "UTF-8"; // Default to UTF-8 encoding int flags = Pattern.MULTILINE; // Default regexp flags try { // Fatal exceptions are handled after this try block // First, process any options int nextarg = 0; while (args[nextarg].charAt(0) == '-') { String option = args[nextarg++]; if (option.equals("-e")) { encodingName = args[nextarg++]; } else if (option.equals("-i")) { // case-insensitive matching flags |= Pattern.CASE_INSENSITIVE; } else if (option.equals("-s")) { // Strict Unicode processing flags |= Pattern.UNICODE_CASE; // case-insensitive Unicode flags |= Pattern.CANON_EQ; // canonicalize Unicode } else { System.err.println("Unknown option: " + option); usage();/*w w w . jav a2 s . co m*/ } } // Get the Charset for converting bytes to chars Charset charset = Charset.forName(encodingName); // Next argument must be a regexp. Compile it to a Pattern object Pattern pattern = Pattern.compile(args[nextarg++], flags); // Require that at least one file is specified if (nextarg == args.length) usage(); // Loop through each of the specified filenames while (nextarg < args.length) { String filename = args[nextarg++]; CharBuffer chars; // This will hold complete text of the file try { // Handle per-file errors locally // Open a FileChannel to the named file FileInputStream stream = new FileInputStream(filename); FileChannel f = stream.getChannel(); // Memory-map the file into one big ByteBuffer. This is // easy but may be somewhat inefficient for short files. ByteBuffer bytes = f.map(FileChannel.MapMode.READ_ONLY, 0, f.size()); // We can close the file once it is is mapped into memory. // Closing the stream closes the channel, too. stream.close(); // Decode the entire ByteBuffer into one big CharBuffer chars = charset.decode(bytes); } catch (IOException e) { // File not found or other problem System.err.println(e); // Print error message continue; // and move on to the next file } // This is the basic regexp loop for finding all matches in a // CharSequence. Note that CharBuffer implements CharSequence. // A Matcher holds state for a given Pattern and text. Matcher matcher = pattern.matcher(chars); while (matcher.find()) { // While there are more matches // Print out details of the match System.out.println(filename + ":" + // file name matcher.start() + ": " + // character pos matcher.group()); // matching text } } } // These are the things that can go wrong in the code above catch (UnsupportedCharsetException e) { // Bad encoding name System.err.println("Unknown encoding: " + encodingName); } catch (PatternSyntaxException e) { // Bad pattern System.err.println("Syntax error in search pattern:\n" + e.getMessage()); } catch (ArrayIndexOutOfBoundsException e) { // Wrong number of arguments usage(); } }
From source file:MainClass.java
public static void main(String[] args) { File aFile = new File("primes.txt"); FileInputStream inFile = null; try {//from w ww . ja va 2 s. c o m inFile = new FileInputStream(aFile); } catch (FileNotFoundException e) { e.printStackTrace(System.err); } FileChannel inChannel = inFile.getChannel(); try { ByteBuffer lengthBuf = ByteBuffer.allocate(8); while (true) { if (inChannel.read(lengthBuf) == -1) { break; } lengthBuf.flip(); int strLength = (int) lengthBuf.getDouble(); ByteBuffer buf = ByteBuffer.allocate(2 * strLength + 8); if (inChannel.read(buf) == -1) { break; } buf.flip(); byte[] strChars = new byte[2 * strLength]; buf.get(strChars); System.out.println(strLength); System.out.println(ByteBuffer.wrap(strChars).asCharBuffer()); System.out.println(buf.getLong()); lengthBuf.clear(); } inFile.close(); } catch (IOException e) { e.printStackTrace(System.err); } }
From source file:NIOCopy.java
public static void main(String args[]) throws Exception { FileInputStream fIn; FileOutputStream fOut;/*from w w w .j a va 2s . c o m*/ FileChannel fIChan, fOChan; long fSize; MappedByteBuffer mBuf; fIn = new FileInputStream(args[0]); fOut = new FileOutputStream(args[1]); fIChan = fIn.getChannel(); fOChan = fOut.getChannel(); fSize = fIChan.size(); mBuf = fIChan.map(FileChannel.MapMode.READ_ONLY, 0, fSize); fOChan.write(mBuf); // this copies the file fIChan.close(); fIn.close(); fOChan.close(); fOut.close(); }