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<TITLE>Creating a File Lock on a File
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<h3>
e181.
Creating a File Lock on a File</h3>
The behavior of the file lock is platform-dependent. On some
platforms, the file lock is advisory, which means that unless an
application checks for a file lock, it will not be prevented from
accessing the file. On other platforms, the file lock is mandatory,
which means that a file lock prevents any application from accessing
the file.
<pre>
try {
// Get a file channel for the file
File file = new File(<font color="#0066ff"><i>"filename"</i></font>);
FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
// Use the file channel to create a lock on the file.
// This method blocks until it can retrieve the lock.
FileLock lock = channel.lock();
// Try acquiring the lock without blocking. This method returns
// null or throws an exception if the file is already locked.
try {
lock = channel.tryLock();
} catch (OverlappingFileLockException e) {
// File is already locked in this thread or virtual machine
}
// Release the lock
lock.release();
// Close the file
channel.close();
} catch (Exception e) {
}
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Related Examples
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e182. <a class="eglink" href="SharedLock.html?l=rel">
Creating a Shared File Lock on a File
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See also:
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Byte%20Buffers">
Byte Buffers
</a>
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Files">
Files
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<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Sockets">
Sockets
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<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Streams">
Streams
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