FileChannel lock

import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
//  j  av  a2 s . c om
public class Main {
  public static void main(String[] argv) throws Exception {
    String filename = "test.dat";

    RandomAccessFile raf1 = new RandomAccessFile(filename, "rw");
    FileChannel fc1 = raf1.getChannel();

    RandomAccessFile raf2 = new RandomAccessFile(filename, "rw");
    FileChannel fc2 = raf2.getChannel();

    System.out.println("Grabbing first lock");
    FileLock lock1 = fc1.lock(0L, Integer.MAX_VALUE, false);

    System.out.println("Grabbing second lock");
    FileLock lock2 = fc2.lock(5, 10, false);

    System.out.println("Exiting");
  }
}

import java.io.FileOutputStream;
import java.nio.channels.FileLock;
/*from  ja v a  2s.  c  o m*/
public class Main {
  public static void main(String[] args) throws Exception {
    FileOutputStream fos = new FileOutputStream("file.txt");
    FileLock fl = fos.getChannel().tryLock();
    if (fl != null) {
      System.out.println("Locked File");
      Thread.sleep(100);
      fl.release();
      System.out.println("Released Lock");
    }
    fos.close();
  }
}