List of usage examples for java.io RandomAccessFile writeInt
public final void writeInt(int v) throws IOException
From source file:MainClass.java
public static void main(String[] args) throws IOException { RandomAccessFile raf = new RandomAccessFile(new File("temp.tmp"), "rw"); raf.writeInt(1); for (int i = 0; i < 10; i++) { raf.seek(raf.length() - 4);//from ww w . j ava2s . c o m raf.writeInt(raf.readInt()); } raf.close(); }
From source file:InputOutputDemoPrimitive.java
public static void main(String[] a) throws Exception { //Read and write parts of file "raf.dat" in arbitrary order: RandomAccessFile raf = new RandomAccessFile("r.dat", "rw"); raf.writeDouble(3.1415);/*from w w w. java 2 s .com*/ raf.writeInt(42); raf.seek(0); System.out.println(raf.readDouble() + " " + raf.readInt()); }
From source file:Main.java
public static void main(String[] args) { try {/* ww w. ja v a 2s . c o m*/ int f = 1234; RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw"); raf.writeInt(f); raf.seek(0); System.out.println(raf.readInt()); raf.seek(0); raf.writeInt(200); raf.seek(0); System.out.println(raf.readInt()); raf.close(); } catch (IOException ex) { ex.printStackTrace(); } }
From source file:Main.java
public static void main(String[] args) { try {//from w w w . ja va2 s . c o m RandomAccessFile raf = new RandomAccessFile("c:\\temp\\RAFsample.txt", "rw"); raf.writeInt(10); raf.writeInt(43); raf.writeInt(88); raf.writeInt(455); raf.seek((3 - 1) * 4); raf.writeInt(99); raf.seek(0); int i = raf.readInt(); while (i != -1) { System.out.println(i); i = raf.readInt(); } raf.close(); } catch (IOException e) { } }
From source file:RandomIOApp.java
public static void main(String args[]) throws IOException { RandomAccessFile file = new RandomAccessFile("test.txt", "rw"); file.writeBoolean(true);/*from w ww .ja va 2 s .co m*/ file.writeInt(123456); file.writeChar('j'); file.writeDouble(1234.56); file.seek(1); System.out.println(file.readInt()); System.out.println(file.readChar()); System.out.println(file.readDouble()); file.seek(0); System.out.println(file.readBoolean()); file.close(); }
From source file:MainClass.java
public static void main(String[] args) { try {//from www. j a v a2 s . c o m RandomAccessFile raf = new RandomAccessFile("c:\\temp\\RAFsample.txt", "rw"); raf.writeInt(10); raf.writeInt(43); raf.writeInt(88); raf.writeInt(455); // change the 3rd integer from 88 to 99 raf.seek((3 - 1) * 4); raf.writeInt(99); raf.seek(0); // go to the first integer int i = raf.readInt(); while (i != -1) { System.out.println(i); i = raf.readInt(); } raf.close(); } catch (IOException e) { } }
From source file:Main.java
public static void main(String[] args) { try {// w w w. j ava 2 s.c o m int i = 123; RandomAccessFile raf = new RandomAccessFile("c:/test.txt", "rw"); // write something in the file raf.writeInt(123); // set the file pointer at 0 position raf.seek(0); // print the int System.out.println(raf.readInt()); // set the file pointer at 0 position raf.seek(0); // write something in the file raf.writeInt(i); // set the file pointer at 0 position raf.seek(0); // print the int System.out.println(raf.readInt()); raf.close(); } catch (IOException ex) { ex.printStackTrace(); } }
From source file:VASSAL.launch.ModuleManager.java
public static void main(String[] args) { // FIXME: We need to catch more exceptions in main() and then exit in // order to avoid situations where the main thread ends due to an uncaught // exception, but there are other threads still running, and so VASSAL // does not quit. For example, this can happen if an IllegalArgumentException // is thrown here... // parse command-line arguments LaunchRequest lr = null;// w ww . ja v a 2 s.c om try { lr = LaunchRequest.parseArgs(args); } catch (LaunchRequestException e) { // FIXME: should be a dialog... System.err.println("VASSAL: " + e.getMessage()); System.exit(1); } // do this before the graphics subsystem fires up or it won't stick System.setProperty("swing.boldMetal", "false"); if (lr.mode == LaunchRequest.Mode.TRANSLATE) { // show the translation window in translation mode SwingUtilities.invokeLater(new Runnable() { public void run() { // FIXME: does this window exit on close? new TranslateVassalWindow(null).setVisible(true); } }); return; } // // How we start exactly one request server: // // To ensure that exactly one process acts as the request server, we // acquire a lock on the ~/VASSAL/key file, and then attempt to acquire // a lock on the ~/VASSAL/lock file. If we cannot lock ~/VASSAL/lock, // then there is already a server running; in that case, we read the // port number and security key from ~/VASSAL/key. If we can lock // ~/VASSAL/lock, then we start the server, write the port number and // key to ~/VASSAL/key, and continue to hold the lock on ~/VASSAL/lock. // Finally, we unlock ~/VASSAL/key and proceed to act as a client, // sending requests over localhost:port using the security key. // // The advantages of this method are: // // (1) No race conditions between processes started at the same time. // (2) No port collisions, because we don't use a predetermined port. // final File keyfile = new File(Info.getConfDir(), "key"); final File lockfile = new File(Info.getConfDir(), "lock"); int port = 0; long key = 0; RandomAccessFile kraf = null; FileLock klock = null; try { // acquire an exclusive lock on the key file kraf = new RandomAccessFile(keyfile, "rw"); try { klock = kraf.getChannel().lock(); } catch (OverlappingFileLockException e) { throw (IOException) new IOException().initCause(e); } // determine whether we are the server or a client // Note: We purposely keep lout open in the case where we are the // server, because closing lout will release the lock. FileLock lock = null; final FileOutputStream lout = new FileOutputStream(lockfile); try { lock = lout.getChannel().tryLock(); } catch (OverlappingFileLockException e) { throw (IOException) new IOException().initCause(e); } if (lock != null) { // we have the lock, so we will be the request server // bind to an available port on the loopback device final ServerSocket serverSocket = new ServerSocket(0, 0, InetAddress.getByName(null)); // write the port number where we listen to the key file port = serverSocket.getLocalPort(); kraf.writeInt(port); // create new security key and write it to the key file key = (long) (Math.random() * Long.MAX_VALUE); kraf.writeLong(key); // create a new Module Manager new ModuleManager(serverSocket, key, lout, lock); } else { // we do not have the lock, so we will be a request client lout.close(); // read the port number we will connect to from the key file port = kraf.readInt(); // read the security key from the key file key = kraf.readLong(); } kraf.close(); } catch (IOException e) { // FIXME: should be a dialog... System.err.println("VASSAL: IO error"); e.printStackTrace(); System.exit(1); } finally { // this will also release the lock on the key file IOUtils.closeQuietly(kraf); } lr.key = key; // pass launch parameters on to the ModuleManager via the socket Socket clientSocket = null; ObjectOutputStream out = null; InputStream in = null; try { clientSocket = new Socket((String) null, port); out = new ObjectOutputStream(new BufferedOutputStream(clientSocket.getOutputStream())); out.writeObject(lr); out.flush(); in = clientSocket.getInputStream(); IOUtils.copy(in, System.err); } catch (IOException e) { // FIXME: should be a dialog... System.err.println("VASSAL: Problem with socket on port " + port); e.printStackTrace(); System.exit(1); } finally { IOUtils.closeQuietly(in); IOUtils.closeQuietly((Closeable) out); IOUtils.closeQuietly(clientSocket); } }
From source file:Main.java
public static void initialWrite(String fileName) throws IOException { RandomAccessFile raf = new RandomAccessFile(fileName, "rw"); raf.writeInt(0); raf.writeUTF("Hello world!"); raf.close();//from www . j a v a 2 s. c o m }
From source file:Main.java
public static void incrementReadCounter(RandomAccessFile raf) throws IOException { long currentPosition = raf.getFilePointer(); raf.seek(0);/* w ww . jav a 2 s . com*/ int counter = raf.readInt(); counter++; raf.seek(0); raf.writeInt(counter); raf.seek(currentPosition); }