// newio/FileLocking.java

// (c)2017 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.channels.FileLock;

import java.util.concurrent.TimeUnit;

public class FileLocking {

public static void main(String[] args) {

try (

FileOutputStream fos =

new FileOutputStream("file.txt");

FileLock fl = fos.getChannel().tryLock()

) {

if (fl != null) {

System.out.println("Locked File");

TimeUnit.MILLISECONDS.sleep(100);

fl.release();

System.out.println("Released Lock");

}

} catch (IOException | InterruptedException e) {

throw new RuntimeException(e);

}

}

}

/* Output:

Locked File

Released Lock

*/