import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileLock;
public class FileLockTest {
public static void main(String[] args) {
try (
var channel = new FileOutputStream("a.txt").getChannel())
{
FileLock flock = channel.lock();
Thread.sleep(100000);
flock.release();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}