io.takari.filemanager.internal

Class DefaultFileManager

java.lang.Object

io.takari.filemanager.internal.DefaultFileManager

All Implemented Interfaces:

FileManager

@Named
 @Singleton
public class DefaultFileManager
extends Object
implements FileManager

Offers advisory file locking independently of the platform. With regard to concurrent readers that don't use any file locking (i.e. 3rd party code accessing files), mandatory locking (as seen on Windows) must be avoided as this would immediately kill the unaware readers. To emulate advisory locking, this implementation uses a dedicated lock file (*.aetherlock) next to the actual file. The inter-process file locking is performed on this lock file, thereby keeping the data file free from locking.

Author:

Benjamin Bentmann

Nested Class Summary

Nested classes/interfaces inherited from interface io.takari.filemanager.FileManager

FileManager.ProgressListener

Constructor Summary

Constructors

Constructor and Description
DefaultFileManager()

Method Summary

Modifier and Type	Method and Description
void	copy(File source, File target)
long	copy(File source, File target, FileManager.ProgressListener listener) Copy src- to target-file.
boolean	mkdirs(File directory) Null-safe variant of File.mkdirs().
void	move(File source, File target)
Lock	readLock(File target) Obtain a lock object that may be used to lock the target file for reading.
void	write(File file, InputStream source)
void	write(File file, String data) Write the given data to a file.
Lock	writeLock(File target) Obtain a lock object that may be used to lock the target file for writing.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultFileManager

public DefaultFileManager()

Method Detail

readLock

public Lock readLock(File target)

Description copied from interface: FileManager

Obtain a lock object that may be used to lock the target file for reading. This method must not lock that file right immediately (see Lock.lock()).

Specified by:

readLock in interface FileManager

Parameters:

target - the file to lock, never null.

Returns:

a lock object, never null.

writeLock

public Lock writeLock(File target)

Description copied from interface: FileManager

Obtain a lock object that may be used to lock the target file for writing. This method must not lock that file right immediately (see Lock.lock()).

Specified by:

writeLock in interface FileManager

Parameters:

target - the file to lock, never null.

Returns:

a lock object, never null.

mkdirs

public boolean mkdirs(File directory)

Null-safe variant of File.mkdirs().

Specified by:

mkdirs in interface FileManager

Parameters:

directory - The directory to create, may be null.

Returns:

true if and only if the directory was created, along with all necessary parent directories; false otherwise

copy

public void copy(File source,
                 File target)
          throws IOException

Specified by:

copy in interface FileManager

Throws:

IOException

copy

public long copy(File source,
                 File target,
                 FileManager.ProgressListener listener)
          throws IOException

Copy src- to target-file. Creates the necessary directories for the target file. In case of an error, the created directories will be left on the file system.

This method performs R/W-locking on the given files to provide concurrent access to files without data corruption, and will honor FileLocks from an external process.

Specified by:

copy in interface FileManager

Parameters:

source - the file to copy from, must not be null.

target - the file to copy to, must not be null.

listener - the listener to notify about the copy progress, may be null.

Returns:

the number of copied bytes.

Throws:

IOException - if an I/O error occurs.

write

public void write(File file,
                  InputStream source)
           throws IOException

Specified by:

write in interface FileManager

Throws:

IOException

write

public void write(File file,
                  String data)
           throws IOException

Write the given data to a file. UTF-8 is assumed as encoding for the data.

Specified by:

write in interface FileManager

Parameters:

file - The file to write to, must not be null. This file will be truncated.

data - The data to write, may be null.

Throws:

IOException - if an I/O error occurs.

move

public void move(File source,
                 File target)
          throws IOException

Specified by:

move in interface FileManager

Throws:

IOException