org.apache.nifi.util.file

Class FileUtils

java.lang.Object

org.apache.nifi.util.file.FileUtils

public class FileUtils
extends Object

A utility class containing a few useful static methods to do typical IO operations.

Field Summary

Fields

Modifier and Type	Field and Description
static long	MILLIS_BETWEEN_ATTEMPTS
static long	TRANSFER_CHUNK_SIZE_BYTES

Constructor Summary

Constructors

Constructor and Description
FileUtils()

Method Summary

Modifier and Type	Method and Description
static void	closeQuietly(Closeable closeable) Closes the given closeable quietly - no logging, no exceptions...
static byte[]	computeMd5Digest(File file) Returns the MD5 hash of the given file.
static byte[]	computeMd5Digest(InputStream stream) Returns the MD5 hash of the given stream.
static long	copy(InputStream in, OutputStream out)
static long	copyBytes(byte[] bytes, File destination, boolean lockOutputFile)
static long	copyFile(File source, File destination, boolean lockInputFile, boolean lockOutputFile, boolean move, org.slf4j.Logger logger) Copies the given source file to the given destination file.
static long	copyFile(File source, File destination, boolean lockInputFile, boolean lockOutputFile, org.slf4j.Logger logger) Copies the given source file to the given destination file.
static long	copyFile(File source, OutputStream stream, boolean closeOutputStream, boolean lockInputFile)
static long	copyFile(InputStream stream, File destination, boolean closeInputStream, boolean lockOutputFile)
static void	deleteFile(File file, boolean recurse)
static boolean	deleteFile(File file, org.slf4j.Logger logger) Deletes the given file.
static boolean	deleteFile(File file, org.slf4j.Logger logger, int attempts) Deletes the given file.
static void	deleteFile(List<File> files, org.slf4j.Logger logger) Deletes all of the given files.
static void	deleteFile(List<File> files, org.slf4j.Logger logger, int attempts) Deletes all of the given files.
static void	deleteFiles(Collection<File> files, boolean recurse) Deletes given files.
static void	deleteFilesInDir(File directory, FilenameFilter filter, org.slf4j.Logger logger) Deletes all files (not directories..) in the given directory (non recursive) that match the given filename filter.
static void	deleteFilesInDir(File directory, FilenameFilter filter, org.slf4j.Logger logger, boolean recurse) Deletes all files (not directories) in the given directory (recursive) that match the given filename filter.
static void	deleteFilesInDir(File directory, FilenameFilter filter, org.slf4j.Logger logger, boolean recurse, boolean deleteEmptyDirectories) Deletes all files (not directories) in the given directory (recursive) that match the given filename filter.
static void	ensureDirectoryExistAndCanAccess(File dir)
static boolean	isSame(File file1, File file2) Returns true if the given files are the same according to their MD5 hash.
static void	releaseQuietly(FileLock lock) Releases the given lock quietly no logging, no exception
static void	renameFile(File source, File destination, int maxAttempts) Renames the given file from the source path to the destination path.
static void	renameFile(File source, File destination, int maxAttempts, boolean replace) Renames the given file from the source path to the destination path.
static void	shredFile(File file, int passes) Randomly generates a sequence of bytes and overwrites the contents of the file a number of times.
static void	sleepQuietly(long millis)
static void	syncWithRestore(File primaryFile, File restoreFile, org.slf4j.Logger logger) Syncs a primary copy of a file with the copy in the restore directory.

Methods inherited from class java.lang.Object

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

Field Detail

TRANSFER_CHUNK_SIZE_BYTES

public static final long TRANSFER_CHUNK_SIZE_BYTES

See Also:

Constant Field Values

MILLIS_BETWEEN_ATTEMPTS

public static final long MILLIS_BETWEEN_ATTEMPTS

See Also:

Constant Field Values

Constructor Detail

FileUtils

public FileUtils()

Method Detail

closeQuietly

public static void closeQuietly(Closeable closeable)

Closes the given closeable quietly - no logging, no exceptions...

Parameters:

closeable - the thing to close

releaseQuietly

public static void releaseQuietly(FileLock lock)

Releases the given lock quietly no logging, no exception

Parameters:

lock - the lock to release

ensureDirectoryExistAndCanAccess

public static void ensureDirectoryExistAndCanAccess(File dir)
                                             throws IOException

Throws:

IOException

deleteFile

public static boolean deleteFile(File file,
                                 org.slf4j.Logger logger)

Deletes the given file. If the given file exists but could not be deleted this will be printed as a warning to the given logger

Parameters:

file - the file to delete

logger - the logger to provide logging information to about the operation

Returns:

true if given file no longer exists

deleteFile

public static boolean deleteFile(File file,
                                 org.slf4j.Logger logger,
                                 int attempts)

Deletes the given file. If the given file exists but could not be deleted this will be printed as a warning to the given logger

Parameters:

file - the file to delete

logger - the logger to write to

attempts - indicates how many times an attempt to delete should be made

Returns:

true if given file no longer exists

deleteFile

public static void deleteFile(List<File> files,
                              org.slf4j.Logger logger)

Deletes all of the given files. If any exist and cannot be deleted that will be printed at warn to the given logger.

Parameters:

files - can be null

logger - can be null

deleteFile

public static void deleteFile(List<File> files,
                              org.slf4j.Logger logger,
                              int attempts)

Deletes all of the given files. If any exist and cannot be deleted that will be printed at warn to the given logger.

Parameters:

files - can be null

logger - can be null

attempts - indicates how many times an attempt should be made to delete each file

deleteFilesInDir

public static void deleteFilesInDir(File directory,
                                    FilenameFilter filter,
                                    org.slf4j.Logger logger)

Deletes all files (not directories..) in the given directory (non recursive) that match the given filename filter. If any file cannot be deleted then this is printed at warn to the given logger.

Parameters:

directory - the directory to scan for files to delete

filter - if null then no filter is used

logger - the logger to use

deleteFilesInDir

public static void deleteFilesInDir(File directory,
                                    FilenameFilter filter,
                                    org.slf4j.Logger logger,
                                    boolean recurse)

Deletes all files (not directories) in the given directory (recursive) that match the given filename filter. If any file cannot be deleted then this is printed at warn to the given logger.

Parameters:

directory - the directory to scan

filter - if null then no filter is used

logger - the logger to use

recurse - indicates whether to recurse subdirectories

deleteFilesInDir

public static void deleteFilesInDir(File directory,
                                    FilenameFilter filter,
                                    org.slf4j.Logger logger,
                                    boolean recurse,
                                    boolean deleteEmptyDirectories)

Deletes all files (not directories) in the given directory (recursive) that match the given filename filter. If any file cannot be deleted then this is printed at warn to the given logger.

Parameters:

directory - the directory to scan

filter - if null then no filter is used

logger - the logger

recurse - whether to recurse subdirectories or not

deleteEmptyDirectories - default is false; if true will delete directories found that are empty

deleteFiles

public static void deleteFiles(Collection<File> files,
                               boolean recurse)
                        throws IOException

Deletes given files.

Parameters:

files - the files to delete

recurse - will recurse if true; false otherwise

Throws:

IOException - if any issues deleting specified files

deleteFile

public static void deleteFile(File file,
                              boolean recurse)
                       throws IOException

Throws:

IOException

shredFile

public static void shredFile(File file,
                             int passes)
                      throws IOException

Randomly generates a sequence of bytes and overwrites the contents of the file a number of times. The file is then deleted.

Parameters:

file - File to be overwritten a number of times and, ultimately, deleted

passes - Number of times file should be overwritten

Throws:

IOException - if something makes shredding or deleting a problem

copy

public static long copy(InputStream in,
                        OutputStream out)
                 throws IOException

Throws:

IOException

copyBytes

public static long copyBytes(byte[] bytes,
                             File destination,
                             boolean lockOutputFile)
                      throws FileNotFoundException,
                             IOException

Throws:

FileNotFoundException

IOException

copyFile

public static long copyFile(File source,
                            File destination,
                            boolean lockInputFile,
                            boolean lockOutputFile,
                            boolean move,
                            org.slf4j.Logger logger)
                     throws FileNotFoundException,
                            IOException

Copies the given source file to the given destination file. The given destination will be overwritten if it already exists.

Parameters:

source - the file to copy

destination - the file to copy to

lockInputFile - if true will lock input file during copy; if false will not

lockOutputFile - if true will lock output file during copy; if false will not

move - if true will perform what is effectively a move operation rather than a pure copy. This allows for potentially highly efficient movement of the file but if not possible this will revert to a copy then delete behavior. If false, then the file is copied and the source file is retained. If a true rename/move occurs then no lock is held during that time.

logger - if failures occur, they will be logged to this logger if possible. If this logger is null, an IOException will instead be thrown, indicating the problem.

Returns:

long number of bytes copied

Throws:

FileNotFoundException - if the source file could not be found

IOException - if unable to read or write the underlying streams

SecurityException - if a security manager denies the needed file operations

copyFile

public static long copyFile(File source,
                            File destination,
                            boolean lockInputFile,
                            boolean lockOutputFile,
                            org.slf4j.Logger logger)
                     throws FileNotFoundException,
                            IOException

Copies the given source file to the given destination file. The given destination will be overwritten if it already exists.

Parameters:

source - the file to copy from

destination - the file to copy to

lockInputFile - if true will lock input file during copy; if false will not

lockOutputFile - if true will lock output file during copy; if false will not

logger - the logger to use

Returns:

long number of bytes copied

Throws:

FileNotFoundException - if the source file could not be found

IOException - if unable to read or write to file

SecurityException - if a security manager denies the needed file operations

copyFile

public static long copyFile(File source,
                            OutputStream stream,
                            boolean closeOutputStream,
                            boolean lockInputFile)
                     throws FileNotFoundException,
                            IOException

Throws:

FileNotFoundException

IOException

copyFile

public static long copyFile(InputStream stream,
                            File destination,
                            boolean closeInputStream,
                            boolean lockOutputFile)
                     throws FileNotFoundException,
                            IOException

Throws:

FileNotFoundException

IOException

renameFile

public static void renameFile(File source,
                              File destination,
                              int maxAttempts)
                       throws IOException

Renames the given file from the source path to the destination path. This handles multiple attempts. This should only be used to rename within a given directory. Renaming across directories might not work well. See the File.renameTo for more information.

Parameters:

source - the file to rename

destination - the file path to rename to

maxAttempts - the max number of attempts to attempt the rename

Throws:

IOException - if rename isn't successful

renameFile

public static void renameFile(File source,
                              File destination,
                              int maxAttempts,
                              boolean replace)
                       throws IOException

Renames the given file from the source path to the destination path. This handles multiple attempts. This should only be used to rename within a given directory. Renaming across directories might not work well. See the File.renameTo for more information.

Parameters:

source - the file to rename

destination - the file path to rename to

maxAttempts - the max number of attempts to attempt the rename

replace - if true and a rename attempt fails will check if a file is already at the destination path. If so it will delete that file and attempt the rename according the remaining maxAttempts. If false, any conflicting files will be left as they were and the rename attempts will fail if conflicting.

Throws:

IOException - if rename isn't successful

sleepQuietly

public static void sleepQuietly(long millis)

syncWithRestore

public static void syncWithRestore(File primaryFile,
                                   File restoreFile,
                                   org.slf4j.Logger logger)
                            throws IOException

Syncs a primary copy of a file with the copy in the restore directory. If the restore directory does not have a file and the primary has a file, the the primary's file is copied to the restore directory. Else if the restore directory has a file, but the primary does not, then the restore's file is copied to the primary directory. Else if the primary file is different than the restore file, then an IllegalStateException is thrown. Otherwise, if neither file exists, then no syncing is performed.

Parameters:

primaryFile - the primary file

restoreFile - the restore file

logger - a logger

Throws:

IOException - if an I/O problem was encountered during syncing

IllegalStateException - if the primary and restore copies exist but are different

isSame

public static boolean isSame(File file1,
                             File file2)
                      throws IOException

Returns true if the given files are the same according to their MD5 hash.

Parameters:

file1 - a file

file2 - a file

Returns:

true if the files are the same; false otherwise

Throws:

IOException - if the MD5 hash could not be computed

computeMd5Digest

public static byte[] computeMd5Digest(File file)
                               throws IOException

Returns the MD5 hash of the given file.

Parameters:

file - a file

Returns:

the MD5 hash

Throws:

IOException - if the MD5 hash could not be computed

computeMd5Digest

public static byte[] computeMd5Digest(InputStream stream)
                               throws IOException

Returns the MD5 hash of the given stream.

Parameters:

stream - an input stream

Returns:

the MD5 hash

Throws:

IOException - if the MD5 hash could not be computed