Unable to lock files on Linux using java.nio.channels.FileLock

Question

I was creating an application in Java for which I want only one instance running. For this purpose I created a file and got a lock while my application is running.

I

Answer 1

Use mkdir. On unix systems this is an atomic operation – it will succeed if a new directory is successfully created, otherwise it will fail.

Example:

File lockFile = new File("/path/to/lockdir");
boolean hasLock = lockFile.mkdir();
if (!hasLock) {
  throw new IOException("could not get lock");
}
// do stuff
lockFile.delete();