Module com.github.nosan.embedded.cassandra

Package com.github.nosan.embedded.cassandra.commons

Class FileLock

java.lang.Object

com.github.nosan.embedded.cassandra.commons.FileLock

All Implemented Interfaces:

AutoCloseable

public final class FileLock
extends Object
implements AutoCloseable

Utility class for obtaining an exclusive lock on a file.

The FileLock class simplifies the process of locking files, allowing controlled access to shared resources in a multi-threaded environment. It uses Java NIO's FileLock to handle file locks.

Usage:

It is recommended to use FileLock with a try-with-resources block to ensure that any underlying file resources are properly released:

 Path lockFile = Path.of("example.lock");
 try (FileLock lock = FileLock.of(lockFile)) {
     if (lock.tryLock(1, TimeUnit.MINUTES)) {
         // Perform actions while the file is locked
     } else {
         // Handle inability to acquire lock
     }
 }
 

Note: An instance of this class should not be shared across different threads.

Since:

4.0.0

Author:

Dmytro Nosan

Method Summary

Modifier and Type	Method	Description
void	close()	Releases all locks and closes the underlying FileChannel.
static FileLock	of(Path file)	Creates a FileLock instance for the specified file.
boolean	tryLock(long timeout, TimeUnit timeUnit)	Attempts to acquire an exclusive lock on the file.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

of

public static FileLock of(Path file)
                   throws IOException

Creates a FileLock instance for the specified file.

The specified file will be opened in write mode with the StandardOpenOption.CREATE option to ensure that the file will be created if it does not already exist.

Parameters:

file - the path to the file to lock

Returns:

a new FileLock instance

Throws:

IOException - if an I/O error occurs while opening the file

NullPointerException - if the file is null

tryLock

public boolean tryLock(long timeout,
                       TimeUnit timeUnit)
                throws FileLockInterruptionException,
                       IOException

Attempts to acquire an exclusive lock on the file.

This method tries to acquire a lock on the file within the given timeout period. If the lock is successfully acquired during this time, the method returns true. Otherwise, it returns false after the timeout period has elapsed.

Parameters:

timeout - the maximum amount of time to wait for the lock

timeUnit - the unit of time for the timeout parameter

Returns:

true if the lock was successfully acquired, otherwise false

Throws:

IllegalArgumentException - if the timeout is negative

FileLockInterruptionException - if the thread is interrupted while waiting for the lock

IOException - if an I/O error occurs while trying to acquire the lock

NullPointerException - if timeUnit is null

close

public void close()
           throws IOException

Releases all locks and closes the underlying FileChannel.

After this method is called, the file associated with this FileLock will no longer be locked, and its FileChannel will be closed.

Specified by:

close in interface AutoCloseable

Throws:

IOException - if an I/O error occurs while closing the FileChannel