FileUtils (Commons IO 2.4 API)

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org.apache.commons.io
Class FileUtils

java.lang.Object
  org.apache.commons.io.FileUtils

public class FileUtils
extends Object
extends Object

General file manipulation utilities.

Facilities are provided in the following areas:

writing to a file
reading from a file
make a directory including parent directories
copying files and directories
deleting files and directories
converting to and from a URL
listing files and directories by filter and extension
comparing file content
file last changed date
calculating a checksum

Origin of code: Excalibur, Alexandria, Commons-Utils

Version:: $Id: FileUtils.java 1349509 2012-06-12 20:39:23Z ggregory $

Field Summary
`static File[]`	`EMPTY_FILE_ARRAY` An empty array of type `File`.
`static long`	`ONE_EB` The number of bytes in an exabyte.
`static BigInteger`	`ONE_EB_BI` The number of bytes in an exabyte.
`static long`	`ONE_GB` The number of bytes in a gigabyte.
`static BigInteger`	`ONE_GB_BI` The number of bytes in a gigabyte.
`static long`	`ONE_KB` The number of bytes in a kilobyte.
`static BigInteger`	`ONE_KB_BI` The number of bytes in a kilobyte.
`static long`	`ONE_MB` The number of bytes in a megabyte.
`static BigInteger`	`ONE_MB_BI` The number of bytes in a megabyte.
`static long`	`ONE_PB` The number of bytes in a petabyte.
`static BigInteger`	`ONE_PB_BI` The number of bytes in a petabyte.
`static long`	`ONE_TB` The number of bytes in a terabyte.
`static BigInteger`	`ONE_TB_BI` The number of bytes in a terabyte.
`static BigInteger`	`ONE_YB` The number of bytes in a yottabyte.
`static BigInteger`	`ONE_ZB` The number of bytes in a zettabyte.

Constructor Summary
`FileUtils()` Instances should NOT be constructed in standard programming.

Method Summary
`static String`	`byteCountToDisplaySize(BigInteger size)` Returns a human-readable version of the file size, where the input represents a specific number of bytes.
`static String`	`byteCountToDisplaySize(long size)` Returns a human-readable version of the file size, where the input represents a specific number of bytes.
`static Checksum`	`checksum(File file, Checksum checksum)` Computes the checksum of a file using the specified checksum object.
`static long`	`checksumCRC32(File file)` Computes the checksum of a file using the CRC32 checksum routine.
`static void`	`cleanDirectory(File directory)` Cleans a directory without deleting it.
`static boolean`	`contentEquals(File file1, File file2)` Compares the contents of two files to determine if they are equal or not.
`static boolean`	`contentEqualsIgnoreEOL(File file1, File file2, String charsetName)` Compares the contents of two files to determine if they are equal or not.
`static File[]`	`convertFileCollectionToFileArray(Collection<File> files)` Converts a Collection containing java.io.File instanced into array representation.
`static void`	`copyDirectory(File srcDir, File destDir)` Copies a whole directory to a new location preserving the file dates.
`static void`	`copyDirectory(File srcDir, File destDir, boolean preserveFileDate)` Copies a whole directory to a new location.
`static void`	`copyDirectory(File srcDir, File destDir, FileFilter filter)` Copies a filtered directory to a new location preserving the file dates.
`static void`	`copyDirectory(File srcDir, File destDir, FileFilter filter, boolean preserveFileDate)` Copies a filtered directory to a new location.
`static void`	`copyDirectoryToDirectory(File srcDir, File destDir)` Copies a directory to within another directory preserving the file dates.
`static void`	`copyFile(File srcFile, File destFile)` Copies a file to a new location preserving the file date.
`static void`	`copyFile(File srcFile, File destFile, boolean preserveFileDate)` Copies a file to a new location.
`static long`	`copyFile(File input, OutputStream output)` Copy bytes from a `File` to an `OutputStream`.
`static void`	`copyFileToDirectory(File srcFile, File destDir)` Copies a file to a directory preserving the file date.
`static void`	`copyFileToDirectory(File srcFile, File destDir, boolean preserveFileDate)` Copies a file to a directory optionally preserving the file date.
`static void`	`copyInputStreamToFile(InputStream source, File destination)` Copies bytes from an `InputStream` `source` to a file `destination`.
`static void`	`copyURLToFile(URL source, File destination)` Copies bytes from the URL `source` to a file `destination`.
`static void`	`copyURLToFile(URL source, File destination, int connectionTimeout, int readTimeout)` Copies bytes from the URL `source` to a file `destination`.
`static void`	`deleteDirectory(File directory)` Deletes a directory recursively.
`static boolean`	`deleteQuietly(File file)` Deletes a file, never throwing an exception.
`static boolean`	`directoryContains(File directory, File child)` Determines whether the `parent` directory contains the `child` element (a file or directory).
`static void`	`forceDelete(File file)` Deletes a file.
`static void`	`forceDeleteOnExit(File file)` Schedules a file to be deleted when JVM exits.
`static void`	`forceMkdir(File directory)` Makes a directory, including any necessary but nonexistent parent directories.
`static File`	`getFile(File directory, String... names)` Construct a file from the set of name elements.
`static File`	`getFile(String... names)` Construct a file from the set of name elements.
`static File`	`getTempDirectory()` Returns a `File` representing the system temporary directory.
`static String`	`getTempDirectoryPath()` Returns the path to the system temporary directory.
`static File`	`getUserDirectory()` Returns a `File` representing the user's home directory.
`static String`	`getUserDirectoryPath()` Returns the path to the user's home directory.
`static boolean`	`isFileNewer(File file, Date date)` Tests if the specified `File` is newer than the specified `Date`.
`static boolean`	`isFileNewer(File file, File reference)` Tests if the specified `File` is newer than the reference `File`.
`static boolean`	`isFileNewer(File file, long timeMillis)` Tests if the specified `File` is newer than the specified time reference.
`static boolean`	`isFileOlder(File file, Date date)` Tests if the specified `File` is older than the specified `Date`.
`static boolean`	`isFileOlder(File file, File reference)` Tests if the specified `File` is older than the reference `File`.
`static boolean`	`isFileOlder(File file, long timeMillis)` Tests if the specified `File` is older than the specified time reference.
`static boolean`	`isSymlink(File file)` Determines whether the specified file is a Symbolic Link rather than an actual file.
`static Iterator<File>`	`iterateFiles(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Allows iteration over the files in given directory (and optionally its subdirectories).
`static Iterator<File>`	`iterateFiles(File directory, String[] extensions, boolean recursive)` Allows iteration over the files in a given directory (and optionally its subdirectories) which match an array of extensions.
`static Iterator<File>`	`iterateFilesAndDirs(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Allows iteration over the files in given directory (and optionally its subdirectories).
`static LineIterator`	`lineIterator(File file)` Returns an Iterator for the lines in a `File` using the default encoding for the VM.
`static LineIterator`	`lineIterator(File file, String encoding)` Returns an Iterator for the lines in a `File`.
`static Collection<File>`	`listFiles(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Finds files within a given directory (and optionally its subdirectories).
`static Collection<File>`	`listFiles(File directory, String[] extensions, boolean recursive)` Finds files within a given directory (and optionally its subdirectories) which match an array of extensions.
`static Collection<File>`	`listFilesAndDirs(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Finds files within a given directory (and optionally its subdirectories).
`static void`	`moveDirectory(File srcDir, File destDir)` Moves a directory.
`static void`	`moveDirectoryToDirectory(File src, File destDir, boolean createDestDir)` Moves a directory to another directory.
`static void`	`moveFile(File srcFile, File destFile)` Moves a file.
`static void`	`moveFileToDirectory(File srcFile, File destDir, boolean createDestDir)` Moves a file to a directory.
`static void`	`moveToDirectory(File src, File destDir, boolean createDestDir)` Moves a file or directory to the destination directory.
`static FileInputStream`	`openInputStream(File file)` Opens a `FileInputStream` for the specified file, providing better error messages than simply calling `new FileInputStream(file)`.
`static FileOutputStream`	`openOutputStream(File file)` Opens a `FileOutputStream` for the specified file, checking and creating the parent directory if it does not exist.
`static FileOutputStream`	`openOutputStream(File file, boolean append)` Opens a `FileOutputStream` for the specified file, checking and creating the parent directory if it does not exist.
`static byte[]`	`readFileToByteArray(File file)` Reads the contents of a file into a byte array.
`static String`	`readFileToString(File file)` Reads the contents of a file into a String using the default encoding for the VM.
`static String`	`readFileToString(File file, Charset encoding)` Reads the contents of a file into a String.
`static String`	`readFileToString(File file, String encoding)` Reads the contents of a file into a String.
`static List<String>`	`readLines(File file)` Reads the contents of a file line by line to a List of Strings using the default encoding for the VM.
`static List<String>`	`readLines(File file, Charset encoding)` Reads the contents of a file line by line to a List of Strings.
`static List<String>`	`readLines(File file, String encoding)` Reads the contents of a file line by line to a List of Strings.
`static long`	`sizeOf(File file)` Returns the size of the specified file or directory.
`static BigInteger`	`sizeOfAsBigInteger(File file)` Returns the size of the specified file or directory.
`static long`	`sizeOfDirectory(File directory)` Counts the size of a directory recursively (sum of the length of all files).
`static BigInteger`	`sizeOfDirectoryAsBigInteger(File directory)` Counts the size of a directory recursively (sum of the length of all files).
`static File`	`toFile(URL url)` Convert from a `URL` to a `File`.
`static File[]`	`toFiles(URL[] urls)` Converts each of an array of `URL` to a `File`.
`static void`	`touch(File file)` Implements the same behaviour as the "touch" utility on Unix.
`static URL[]`	`toURLs(File[] files)` Converts each of an array of `File` to a `URL`.
`static boolean`	`waitFor(File file, int seconds)` Waits for NFS to propagate a file creation, imposing a timeout.
`static void`	`write(File file, CharSequence data)` Writes a CharSequence to a file creating the file if it does not exist using the default encoding for the VM.
`static void`	`write(File file, CharSequence data, boolean append)` Writes a CharSequence to a file creating the file if it does not exist using the default encoding for the VM.
`static void`	`write(File file, CharSequence data, Charset encoding)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(File file, CharSequence data, Charset encoding, boolean append)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(File file, CharSequence data, String encoding)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(File file, CharSequence data, String encoding, boolean append)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`writeByteArrayToFile(File file, byte[] data)` Writes a byte array to a file creating the file if it does not exist.
`static void`	`writeByteArrayToFile(File file, byte[] data, boolean append)` Writes a byte array to a file creating the file if it does not exist.
`static void`	`writeLines(File file, Collection<?> lines)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, Collection<?> lines, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, Collection<?> lines, String lineEnding)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, Collection<?> lines, String lineEnding, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, String encoding, Collection<?> lines)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, String encoding, Collection<?> lines, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line, optionally appending.
`static void`	`writeLines(File file, String encoding, Collection<?> lines, String lineEnding)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(File file, String encoding, Collection<?> lines, String lineEnding, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeStringToFile(File file, String data)` Writes a String to a file creating the file if it does not exist using the default encoding for the VM.
`static void`	`writeStringToFile(File file, String data, boolean append)` Writes a String to a file creating the file if it does not exist using the default encoding for the VM.
`static void`	`writeStringToFile(File file, String data, Charset encoding)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(File file, String data, Charset encoding, boolean append)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(File file, String data, String encoding)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(File file, String data, String encoding, boolean append)` Writes a String to a file creating the file if it does not exist.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

ONE_KB

public static final long ONE_KB

The number of bytes in a kilobyte.

See Also:: Constant Field Values

ONE_KB_BI

public static final BigInteger ONE_KB_BI

The number of bytes in a kilobyte.

Since:: 2.4

ONE_MB

public static final long ONE_MB

The number of bytes in a megabyte.

See Also:: Constant Field Values

ONE_MB_BI

public static final BigInteger ONE_MB_BI

The number of bytes in a megabyte.

Since:: 2.4

ONE_GB

public static final long ONE_GB

The number of bytes in a gigabyte.

See Also:: Constant Field Values

ONE_GB_BI

public static final BigInteger ONE_GB_BI

The number of bytes in a gigabyte.

Since:: 2.4

ONE_TB

public static final long ONE_TB

The number of bytes in a terabyte.

See Also:: Constant Field Values

ONE_TB_BI

public static final BigInteger ONE_TB_BI

The number of bytes in a terabyte.

Since:: 2.4

ONE_PB

public static final long ONE_PB

The number of bytes in a petabyte.

See Also:: Constant Field Values

ONE_PB_BI

public static final BigInteger ONE_PB_BI

The number of bytes in a petabyte.

Since:: 2.4

ONE_EB

public static final long ONE_EB

The number of bytes in an exabyte.

See Also:: Constant Field Values

ONE_EB_BI

public static final BigInteger ONE_EB_BI

The number of bytes in an exabyte.

Since:: 2.4

ONE_ZB

public static final BigInteger ONE_ZB

The number of bytes in a zettabyte.

ONE_YB

public static final BigInteger ONE_YB

The number of bytes in a yottabyte.

EMPTY_FILE_ARRAY

public static final File[] EMPTY_FILE_ARRAY

An empty array of type File.

Constructor Detail

FileUtils

public FileUtils()

Instances should NOT be constructed in standard programming.

Method Detail

getFile

public static File getFile(File directory,
                           String... names)

Construct a file from the set of name elements.

Parameters:: directory - the parent directory; names - the name elements
Returns:: the file
Since:: 2.1

getFile

public static File getFile(String... names)

Construct a file from the set of name elements.

Parameters:: names - the name elements
Returns:: the file
Since:: 2.1

getTempDirectoryPath

public static String getTempDirectoryPath()

Returns the path to the system temporary directory.

Returns:: the path to the system temporary directory.
Since:: 2.0

getTempDirectory

public static File getTempDirectory()

Returns a File representing the system temporary directory.

Returns:: the system temporary directory.
Since:: 2.0

getUserDirectoryPath

public static String getUserDirectoryPath()

Returns the path to the user's home directory.

Returns:: the path to the user's home directory.
Since:: 2.0

getUserDirectory

public static File getUserDirectory()

Returns a File representing the user's home directory.

Returns:: the user's home directory.
Since:: 2.0

openInputStream

public static FileInputStream openInputStream(File file)
                                       throws IOException

Opens a FileInputStream for the specified file, providing better error messages than simply calling new FileInputStream(file).

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

An exception is thrown if the file does not exist. An exception is thrown if the file object exists but is a directory. An exception is thrown if the file exists but cannot be read.

Parameters:: file - the file to open for input, must not be null
Returns:: a new FileInputStream for the specified file
Throws:: FileNotFoundException - if the file does not exist; IOException - if the file object is a directory; IOException - if the file cannot be read
Since:: 1.3

openOutputStream

public static FileOutputStream openOutputStream(File file)
                                         throws IOException

Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

The parent directory will be created if it does not exist. The file will be created if it does not exist. An exception is thrown if the file object exists but is a directory. An exception is thrown if the file exists but cannot be written to. An exception is thrown if the parent directory cannot be created.

Parameters:: file - the file to open for output, must not be null
Returns:: a new FileOutputStream for the specified file
Throws:: IOException - if the file object is a directory; IOException - if the file cannot be written to; IOException - if a parent directory needs creating but that fails
Since:: 1.3

openOutputStream

public static FileOutputStream openOutputStream(File file,
                                                boolean append)
                                         throws IOException

Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

Parameters:: file - the file to open for output, must not be null; append - if true, then bytes will be added to the end of the file rather than overwriting
Returns:: a new FileOutputStream for the specified file
Throws:: IOException - if the file object is a directory; IOException - if the file cannot be written to; IOException - if a parent directory needs creating but that fails
Since:: 2.1

byteCountToDisplaySize

public static String byteCountToDisplaySize(BigInteger size)

Returns a human-readable version of the file size, where the input represents a specific number of bytes.

If the size is over 1GB, the size is returned as the number of whole GB, i.e. the size is rounded down to the nearest GB boundary.

Similarly for the 1MB and 1KB boundaries.

Parameters:: size - the number of bytes
Returns:: a human-readable display value (includes units - EB, PB, TB, GB, MB, KB or bytes)
Since:: 2.4
See Also:: IO-226 - should the rounding be changed?

byteCountToDisplaySize

public static String byteCountToDisplaySize(long size)

Returns a human-readable version of the file size, where the input represents a specific number of bytes.

If the size is over 1GB, the size is returned as the number of whole GB, i.e. the size is rounded down to the nearest GB boundary.

Similarly for the 1MB and 1KB boundaries.

Parameters:: size - the number of bytes
Returns:: a human-readable display value (includes units - EB, PB, TB, GB, MB, KB or bytes)
See Also:: IO-226 - should the rounding be changed?

touch

public static void touch(File file)
                  throws IOException

Implements the same behaviour as the "touch" utility on Unix. It creates a new file with size 0 or, if the file exists already, it is opened and closed without modifying it, but updating the file date and time.

NOTE: As from v1.3, this method throws an IOException if the last modified date of the file cannot be set. Also, as from v1.3 this method creates parent directories if they do not exist.

Parameters:: file - the File to touch
Throws:: IOException - If an I/O problem occurs

convertFileCollectionToFileArray

public static File[] convertFileCollectionToFileArray(Collection<File> files)

Converts a Collection containing java.io.File instanced into array representation. This is to account for the difference between File.listFiles() and FileUtils.listFiles().

Parameters:: files - a Collection containing java.io.File instances
Returns:: an array of java.io.File

listFiles

public static Collection<File> listFiles(File directory,
                                         IOFileFilter fileFilter,
                                         IOFileFilter dirFilter)

Finds files within a given directory (and optionally its subdirectories). All files found are filtered by an IOFileFilter.

If your search should recurse into subdirectories you can pass in an IOFileFilter for directories. You don't need to bind a DirectoryFileFilter (via logical AND) to this filter. This method does that for you.

An example: If you want to search through all directories called "temp" you pass in FileFilterUtils.NameFileFilter("temp")

Another common usage of this method is find files in a directory tree but ignoring the directories generated CVS. You can simply pass in FileFilterUtils.makeCVSAware(null).

Parameters:: directory - the directory to search in; fileFilter - filter to apply when finding files.; dirFilter - optional filter to apply when finding subdirectories. If this parameter is null, subdirectories will not be included in the search. Use TrueFileFilter.INSTANCE to match all directories.
Returns:: an collection of java.io.File with the matching files
See Also:: FileFilterUtils, NameFileFilter

listFilesAndDirs

public static Collection<File> listFilesAndDirs(File directory,
                                                IOFileFilter fileFilter,
                                                IOFileFilter dirFilter)

Finds files within a given directory (and optionally its subdirectories). All files found are filtered by an IOFileFilter.

The resulting collection includes the subdirectories themselves.

Parameters:: directory - the directory to search in; fileFilter - filter to apply when finding files.; dirFilter - optional filter to apply when finding subdirectories. If this parameter is null, subdirectories will not be included in the search. Use TrueFileFilter.INSTANCE to match all directories.
Returns:: an collection of java.io.File with the matching files
Since:: 2.2
See Also:: listFiles(java.io.File, org.apache.commons.io.filefilter.IOFileFilter, org.apache.commons.io.filefilter.IOFileFilter), FileFilterUtils, NameFileFilter

iterateFiles

public static Iterator<File> iterateFiles(File directory,
                                          IOFileFilter fileFilter,
                                          IOFileFilter dirFilter)

Allows iteration over the files in given directory (and optionally its subdirectories).

All files found are filtered by an IOFileFilter. This method is based on listFiles(File, IOFileFilter, IOFileFilter), which supports Iterable ('foreach' loop).

Parameters:: directory - the directory to search in; fileFilter - filter to apply when finding files.; dirFilter - optional filter to apply when finding subdirectories. If this parameter is null, subdirectories will not be included in the search. Use TrueFileFilter.INSTANCE to match all directories.
Returns:: an iterator of java.io.File for the matching files
Since:: 1.2
See Also:: FileFilterUtils, NameFileFilter

iterateFilesAndDirs

public static Iterator<File> iterateFilesAndDirs(File directory,
                                                 IOFileFilter fileFilter,
                                                 IOFileFilter dirFilter)

Allows iteration over the files in given directory (and optionally its subdirectories).

All files found are filtered by an IOFileFilter. This method is based on listFilesAndDirs(File, IOFileFilter, IOFileFilter), which supports Iterable ('foreach' loop).

The resulting iterator includes the subdirectories themselves.

Parameters:: directory - the directory to search in; fileFilter - filter to apply when finding files.; dirFilter - optional filter to apply when finding subdirectories. If this parameter is null, subdirectories will not be included in the search. Use TrueFileFilter.INSTANCE to match all directories.
Returns:: an iterator of java.io.File for the matching files
Since:: 2.2
See Also:: FileFilterUtils, NameFileFilter

listFiles

public static Collection<File> listFiles(File directory,
                                         String[] extensions,
                                         boolean recursive)

Finds files within a given directory (and optionally its subdirectories) which match an array of extensions.

Parameters:: directory - the directory to search in; extensions - an array of extensions, ex. {"java","xml"}. If this parameter is null, all files are returned.; recursive - if true all subdirectories are searched as well
Returns:: an collection of java.io.File with the matching files

iterateFiles

public static Iterator<File> iterateFiles(File directory,
                                          String[] extensions,
                                          boolean recursive)

Allows iteration over the files in a given directory (and optionally its subdirectories) which match an array of extensions. This method is based on listFiles(File, String[], boolean), which supports Iterable ('foreach' loop).

Parameters:: directory - the directory to search in; extensions - an array of extensions, ex. {"java","xml"}. If this parameter is null, all files are returned.; recursive - if true all subdirectories are searched as well
Returns:: an iterator of java.io.File with the matching files
Since:: 1.2

contentEquals

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

Compares the contents of two files to determine if they are equal or not.

This method checks to see if the two files are different lengths or if they point to the same file, before resorting to byte-by-byte comparison of the contents.

Code origin: Avalon

Parameters:: file1 - the first file; file2 - the second file
Returns:: true if the content of the files are equal or they both don't exist, false otherwise
Throws:: IOException - in case of an I/O error

contentEqualsIgnoreEOL

public static boolean contentEqualsIgnoreEOL(File file1,
                                             File file2,
                                             String charsetName)
                                      throws IOException

Compares the contents of two files to determine if they are equal or not.

This method checks to see if the two files point to the same file, before resorting to line-by-line comparison of the contents.

Parameters:: file1 - the first file; file2 - the second file; charsetName - the character encoding to be used. May be null, in which case the platform default is used
Returns:: true if the content of the files are equal or neither exists, false otherwise
Throws:: IOException - in case of an I/O error
Since:: 2.2
See Also:: IOUtils.contentEqualsIgnoreEOL(Reader, Reader)

toFile

public static File toFile(URL url)

Convert from a URL to a File.

From version 1.1 this method will decode the URL. Syntax such as file:///my%20docs/file.txt will be correctly decoded to /my docs/file.txt. Starting with version 1.5, this method uses UTF-8 to decode percent-encoded octets to characters. Additionally, malformed percent-encoded octets are handled leniently by passing them through literally.

Parameters:: url - the file URL to convert, null returns null
Returns:: the equivalent File object, or null if the URL's protocol is not file

toFiles

public static File[] toFiles(URL[] urls)

Converts each of an array of URL to a File.

Returns an array of the same size as the input. If the input is null, an empty array is returned. If the input contains null, the output array contains null at the same index.

This method will decode the URL. Syntax such as file:///my%20docs/file.txt will be correctly decoded to /my docs/file.txt.

Parameters:: urls - the file URLs to convert, null returns empty array
Returns:: a non-null array of Files matching the input, with a null item if there was a null at that index in the input array
Throws:: IllegalArgumentException - if any file is not a URL file; IllegalArgumentException - if any file is incorrectly encoded
Since:: 1.1

toURLs

public static URL[] toURLs(File[] files)
                    throws IOException

Converts each of an array of File to a URL.

Returns an array of the same size as the input.

Parameters:: files - the files to convert, must not be null
Returns:: an array of URLs matching the input
Throws:: IOException - if a file cannot be converted; NullPointerException - if the parameter is null

copyFileToDirectory

public static void copyFileToDirectory(File srcFile,
                                       File destDir)
                                throws IOException

Copies a file to a directory preserving the file date.

This method copies the contents of the specified source file to a file of the same name in the specified destination directory. The destination directory is created if it does not exist. If the destination file exists, then this method will overwrite it.

Note: This method tries to preserve the file's last modified date/times using File.setLastModified(long), however it is not guaranteed that the operation will succeed. If the modification operation fails, no indication is provided.

Parameters:: srcFile - an existing file to copy, must not be null; destDir - the directory to place the copy in, must not be null
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
See Also:: copyFile(File, File, boolean)

copyFileToDirectory

public static void copyFileToDirectory(File srcFile,
                                       File destDir,
                                       boolean preserveFileDate)
                                throws IOException

Copies a file to a directory optionally preserving the file date.

Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using File.setLastModified(long), however it is not guaranteed that the operation will succeed. If the modification operation fails, no indication is provided.

Parameters:: srcFile - an existing file to copy, must not be null; destDir - the directory to place the copy in, must not be null; preserveFileDate - true if the file date of the copy should be the same as the original
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.3
See Also:: copyFile(File, File, boolean)

copyFile

public static void copyFile(File srcFile,
                            File destFile)
                     throws IOException

Copies a file to a new location preserving the file date.

This method copies the contents of the specified source file to the specified destination file. The directory holding the destination file is created if it does not exist. If the destination file exists, then this method will overwrite it.

Parameters:: srcFile - an existing file to copy, must not be null; destFile - the new file, must not be null
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
See Also:: copyFileToDirectory(File, File)

copyFile

public static void copyFile(File srcFile,
                            File destFile,
                            boolean preserveFileDate)
                     throws IOException

Copies a file to a new location.

Parameters:: srcFile - an existing file to copy, must not be null; destFile - the new file, must not be null; preserveFileDate - true if the file date of the copy should be the same as the original
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
See Also:: copyFileToDirectory(File, File, boolean)

copyFile

public static long copyFile(File input,
                            OutputStream output)
                     throws IOException

Copy bytes from a File to an OutputStream.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Parameters:: input - the File to read from; output - the OutputStream to write to
Returns:: the number of bytes copied
Throws:: NullPointerException - if the input or output is null; IOException - if an I/O error occurs
Since:: 2.1

copyDirectoryToDirectory

public static void copyDirectoryToDirectory(File srcDir,
                                            File destDir)
                                     throws IOException

Copies a directory to within another directory preserving the file dates.

This method copies the source directory and all its contents to a directory of the same name in the specified destination directory.

The destination directory is created if it does not exist. If the destination directory did exist, then this method merges the source with the destination, with the source taking precedence.

Note: This method tries to preserve the files' last modified date/times using File.setLastModified(long), however it is not guaranteed that those operations will succeed. If the modification operation fails, no indication is provided.

Parameters:: srcDir - an existing directory to copy, must not be null; destDir - the directory to place the copy in, must not be null
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.2

copyDirectory

public static void copyDirectory(File srcDir,
                                 File destDir)
                          throws IOException

Copies a whole directory to a new location preserving the file dates.

This method copies the specified directory and all its child directories and files to the specified destination. The destination is the new location and name of the directory.

The destination directory is created if it does not exist. If the destination directory did exist, then this method merges the source with the destination, with the source taking precedence.

Parameters:: srcDir - an existing directory to copy, must not be null; destDir - the new directory, must not be null
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.1

copyDirectory

public static void copyDirectory(File srcDir,
                                 File destDir,
                                 boolean preserveFileDate)
                          throws IOException

Copies a whole directory to a new location.

This method copies the contents of the specified source directory to within the specified destination directory.

The destination directory is created if it does not exist. If the destination directory did exist, then this method merges the source with the destination, with the source taking precedence.

Note: Setting preserveFileDate to true tries to preserve the files' last modified date/times using File.setLastModified(long), however it is not guaranteed that those operations will succeed. If the modification operation fails, no indication is provided.

Parameters:: srcDir - an existing directory to copy, must not be null; destDir - the new directory, must not be null; preserveFileDate - true if the file date of the copy should be the same as the original
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.1

copyDirectory

public static void copyDirectory(File srcDir,
                                 File destDir,
                                 FileFilter filter)
                          throws IOException

Copies a filtered directory to a new location preserving the file dates.

This method copies the contents of the specified source directory to within the specified destination directory.

The destination directory is created if it does not exist. If the destination directory did exist, then this method merges the source with the destination, with the source taking precedence.

Example: Copy directories only

  // only copy the directory structure
  FileUtils.copyDirectory(srcDir, destDir, DirectoryFileFilter.DIRECTORY);

Example: Copy directories and txt files

  // Create a filter for ".txt" files
  IOFileFilter txtSuffixFilter = FileFilterUtils.suffixFileFilter(".txt");
  IOFileFilter txtFiles = FileFilterUtils.andFileFilter(FileFileFilter.FILE, txtSuffixFilter);

  // Create a filter for either directories or ".txt" files
  FileFilter filter = FileFilterUtils.orFileFilter(DirectoryFileFilter.DIRECTORY, txtFiles);

  // Copy using the filter
  FileUtils.copyDirectory(srcDir, destDir, filter);

Parameters:: srcDir - an existing directory to copy, must not be null; destDir - the new directory, must not be null; filter - the filter to apply, null means copy all directories and files should be the same as the original
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.4

copyDirectory

public static void copyDirectory(File srcDir,
                                 File destDir,
                                 FileFilter filter,
                                 boolean preserveFileDate)
                          throws IOException

Copies a filtered directory to a new location.

This method copies the contents of the specified source directory to within the specified destination directory.

The destination directory is created if it does not exist. If the destination directory did exist, then this method merges the source with the destination, with the source taking precedence.

Example: Copy directories only

  // only copy the directory structure
  FileUtils.copyDirectory(srcDir, destDir, DirectoryFileFilter.DIRECTORY, false);

Example: Copy directories and txt files

  // Create a filter for ".txt" files
  IOFileFilter txtSuffixFilter = FileFilterUtils.suffixFileFilter(".txt");
  IOFileFilter txtFiles = FileFilterUtils.andFileFilter(FileFileFilter.FILE, txtSuffixFilter);

  // Create a filter for either directories or ".txt" files
  FileFilter filter = FileFilterUtils.orFileFilter(DirectoryFileFilter.DIRECTORY, txtFiles);

  // Copy using the filter
  FileUtils.copyDirectory(srcDir, destDir, filter, false);

Parameters:: srcDir - an existing directory to copy, must not be null; destDir - the new directory, must not be null; filter - the filter to apply, null means copy all directories and files; preserveFileDate - true if the file date of the copy should be the same as the original
Throws:: NullPointerException - if source or destination is null; IOException - if source or destination is invalid; IOException - if an IO error occurs during copying
Since:: 1.4

copyURLToFile

public static void copyURLToFile(URL source,
                                 File destination)
                          throws IOException

Copies bytes from the URL source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.

Warning: this method does not set a connection or read timeout and thus might block forever. Use copyURLToFile(URL, File, int, int) with reasonable timeouts to prevent this.

Parameters:: source - the URL to copy bytes from, must not be null; destination - the non-directory File to write bytes to (possibly overwriting), must not be null
Throws:: IOException - if source URL cannot be opened; IOException - if destination is a directory; IOException - if destination cannot be written; IOException - if destination needs creating but can't be; IOException - if an IO error occurs during copying

copyURLToFile

public static void copyURLToFile(URL source,
                                 File destination,
                                 int connectionTimeout,
                                 int readTimeout)
                          throws IOException

Copies bytes from the URL source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.

Parameters:: source - the URL to copy bytes from, must not be null; destination - the non-directory File to write bytes to (possibly overwriting), must not be null; connectionTimeout - the number of milliseconds until this method will timeout if no connection could be established to the source; readTimeout - the number of milliseconds until this method will timeout if no data could be read from the source
Throws:: IOException - if source URL cannot be opened; IOException - if destination is a directory; IOException - if destination cannot be written; IOException - if destination needs creating but can't be; IOException - if an IO error occurs during copying
Since:: 2.0

copyInputStreamToFile

public static void copyInputStreamToFile(InputStream source,
                                         File destination)
                                  throws IOException

Copies bytes from an InputStream source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.

Parameters:: source - the InputStream to copy bytes from, must not be null; destination - the non-directory File to write bytes to (possibly overwriting), must not be null
Throws:: IOException - if destination is a directory; IOException - if destination cannot be written; IOException - if destination needs creating but can't be; IOException - if an IO error occurs during copying
Since:: 2.0

deleteDirectory

public static void deleteDirectory(File directory)
                            throws IOException

Deletes a directory recursively.

Parameters:: directory - directory to delete
Throws:: IOException - in case deletion is unsuccessful

deleteQuietly

public static boolean deleteQuietly(File file)

Deletes a file, never throwing an exception. If file is a directory, delete it and all sub-directories.

The difference between File.delete() and this method are:

A directory to be deleted does not have to be empty.
No exceptions are thrown when a file or directory cannot be deleted.

Parameters:: file - file or directory to delete, can be null
Returns:: true if the file or directory was deleted, otherwise false
Since:: 1.4

directoryContains

public static boolean directoryContains(File directory,
                                        File child)
                                 throws IOException

Determines whether the parent directory contains the child element (a file or directory).

Files are normalized before comparison.

Edge cases:

A directory must not be null: if null, throw IllegalArgumentException
A directory must be a directory: if not a directory, throw IllegalArgumentException
A directory does not contain itself: return false
A null child file is not contained in any parent: return false

Parameters:: directory - the file to consider as the parent.; child - the file to consider as the child.
Returns:: true is the candidate leaf is under by the specified composite. False otherwise.
Throws:: IOException - if an IO error occurs while checking the files.
Since:: 2.2
See Also:: FilenameUtils.directoryContains(String, String)

cleanDirectory

public static void cleanDirectory(File directory)
                           throws IOException

Cleans a directory without deleting it.

Parameters:: directory - directory to clean
Throws:: IOException - in case cleaning is unsuccessful

waitFor

public static boolean waitFor(File file,
                              int seconds)

Waits for NFS to propagate a file creation, imposing a timeout.

This method repeatedly tests File.exists() until it returns true up to the maximum time specified in seconds.

Parameters:: file - the file to check, must not be null; seconds - the maximum time in seconds to wait
Returns:: true if file exists
Throws:: NullPointerException - if the file is null

readFileToString

public static String readFileToString(File file,
                                      Charset encoding)
                               throws IOException

Reads the contents of a file into a String. The file is always closed.

Parameters:: file - the file to read, must not be null; encoding - the encoding to use, null means platform default
Returns:: the file contents, never null
Throws:: IOException - in case of an I/O error
Since:: 2.3

readFileToString

public static String readFileToString(File file,
                                      String encoding)
                               throws IOException

Reads the contents of a file into a String. The file is always closed.

Parameters:: file - the file to read, must not be null; encoding - the encoding to use, null means platform default
Returns:: the file contents, never null
Throws:: IOException - in case of an I/O error; UnsupportedCharsetException - thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:: 2.3

readFileToString

public static String readFileToString(File file)
                               throws IOException

Reads the contents of a file into a String using the default encoding for the VM. The file is always closed.

Parameters:: file - the file to read, must not be null
Returns:: the file contents, never null
Throws:: IOException - in case of an I/O error
Since:: 1.3.1

readFileToByteArray

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

Reads the contents of a file into a byte array. The file is always closed.

Parameters:: file - the file to read, must not be null
Returns:: the file contents, never null
Throws:: IOException - in case of an I/O error
Since:: 1.1

readLines

public static List<String> readLines(File file,
                                     Charset encoding)
                              throws IOException

Reads the contents of a file line by line to a List of Strings. The file is always closed.

Parameters:: file - the file to read, must not be null; encoding - the encoding to use, null means platform default
Returns:: the list of Strings representing each line in the file, never null
Throws:: IOException - in case of an I/O error
Since:: 2.3

readLines

public static List<String> readLines(File file,
                                     String encoding)
                              throws IOException

Reads the contents of a file line by line to a List of Strings. The file is always closed.

Parameters:: file - the file to read, must not be null; encoding - the encoding to use, null means platform default
Returns:: the list of Strings representing each line in the file, never null
Throws:: IOException - in case of an I/O error; UnsupportedCharsetException - thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported.
Since:: 1.1

readLines

public static List<String> readLines(File file)
                              throws IOException

Reads the contents of a file line by line to a List of Strings using the default encoding for the VM. The file is always closed.

Parameters:: file - the file to read, must not be null
Returns:: the list of Strings representing each line in the file, never null
Throws:: IOException - in case of an I/O error
Since:: 1.3

lineIterator

public static LineIterator lineIterator(File file,
                                        String encoding)
                                 throws IOException

Returns an Iterator for the lines in a File.

This method opens an InputStream for the file. When you have finished with the iterator you should close the stream to free internal resources. This can be done by calling the LineIterator.close() or LineIterator.closeQuietly(LineIterator) method.

The recommended usage pattern is:

 LineIterator it = FileUtils.lineIterator(file, "UTF-8");
 try {
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   LineIterator.closeQuietly(iterator);
 }

If an exception occurs during the creation of the iterator, the underlying stream is closed.

Parameters:: file - the file to open for input, must not be null; encoding - the encoding to use, null means platform default
Returns:: an Iterator of the lines in the file, never null
Throws:: IOException - in case of an I/O error (file closed)
Since:: 1.2

lineIterator

public static LineIterator lineIterator(File file)
                                 throws IOException

Returns an Iterator for the lines in a File using the default encoding for the VM.

Parameters:: file - the file to open for input, must not be null
Returns:: an Iterator of the lines in the file, never null
Throws:: IOException - in case of an I/O error (file closed)
Since:: 1.3
See Also:: lineIterator(File, String)

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     Charset encoding)
                              throws IOException

Writes a String to a file creating the file if it does not exist. NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 2.4

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     String encoding)
                              throws IOException

Writes a String to a file creating the file if it does not exist. NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     Charset encoding,
                                     boolean append)
                              throws IOException

Writes a String to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default; append - if true, then the String will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.3

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     String encoding,
                                     boolean append)
                              throws IOException

Writes a String to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default; append - if true, then the String will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error; UnsupportedCharsetException - thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported by the VM
Since:: 2.1

writeStringToFile

public static void writeStringToFile(File file,
                                     String data)
                              throws IOException

Writes a String to a file creating the file if it does not exist using the default encoding for the VM.

Parameters:: file - the file to write; data - the content to write to the file
Throws:: IOException - in case of an I/O error

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     boolean append)
                              throws IOException

Writes a String to a file creating the file if it does not exist using the default encoding for the VM.

Parameters:: file - the file to write; data - the content to write to the file; append - if true, then the String will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.1

write

public static void write(File file,
                         CharSequence data)
                  throws IOException

Writes a CharSequence to a file creating the file if it does not exist using the default encoding for the VM.

Parameters:: file - the file to write; data - the content to write to the file
Throws:: IOException - in case of an I/O error
Since:: 2.0

write

public static void write(File file,
                         CharSequence data,
                         boolean append)
                  throws IOException

Writes a CharSequence to a file creating the file if it does not exist using the default encoding for the VM.

Parameters:: file - the file to write; data - the content to write to the file; append - if true, then the data will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.1

write

public static void write(File file,
                         CharSequence data,
                         Charset encoding)
                  throws IOException

Writes a CharSequence to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default
Throws:: IOException - in case of an I/O error
Since:: 2.3

write

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

Writes a CharSequence to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 2.0

write

public static void write(File file,
                         CharSequence data,
                         Charset encoding,
                         boolean append)
                  throws IOException

Writes a CharSequence to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default; append - if true, then the data will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.3

write

public static void write(File file,
                         CharSequence data,
                         String encoding,
                         boolean append)
                  throws IOException

Writes a CharSequence to a file creating the file if it does not exist.

Parameters:: file - the file to write; data - the content to write to the file; encoding - the encoding to use, null means platform default; append - if true, then the data will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error; UnsupportedCharsetException - thrown instead of UnsupportedEncodingException in version 2.2 if the encoding is not supported by the VM
Since:: IO 2.1

writeByteArrayToFile

public static void writeByteArrayToFile(File file,
                                        byte[] data)
                                 throws IOException

Writes a byte array to a file creating the file if it does not exist.

NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:: file - the file to write to; data - the content to write to the file
Throws:: IOException - in case of an I/O error
Since:: 1.1

writeByteArrayToFile

public static void writeByteArrayToFile(File file,
                                        byte[] data,
                                        boolean append)
                                 throws IOException

Writes a byte array to a file creating the file if it does not exist.

Parameters:: file - the file to write to; data - the content to write to the file; append - if true, then bytes will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: IO 2.1

writeLines

public static void writeLines(File file,
                              String encoding,
                              Collection<?> lines)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the default line ending will be used.

NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:: file - the file to write to; encoding - the encoding to use, null means platform default; lines - the lines to write, null entries produce blank lines
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 1.1

writeLines

public static void writeLines(File file,
                              String encoding,
                              Collection<?> lines,
                              boolean append)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line, optionally appending. The specified character encoding and the default line ending will be used.

Parameters:: file - the file to write to; encoding - the encoding to use, null means platform default; lines - the lines to write, null entries produce blank lines; append - if true, then the lines will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 2.1

writeLines

public static void writeLines(File file,
                              Collection<?> lines)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the default line ending will be used.

Parameters:: file - the file to write to; lines - the lines to write, null entries produce blank lines
Throws:: IOException - in case of an I/O error
Since:: 1.3

writeLines

public static void writeLines(File file,
                              Collection<?> lines,
                              boolean append)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the default line ending will be used.

Parameters:: file - the file to write to; lines - the lines to write, null entries produce blank lines; append - if true, then the lines will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.1

writeLines

public static void writeLines(File file,
                              String encoding,
                              Collection<?> lines,
                              String lineEnding)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the line ending will be used.

NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:: file - the file to write to; encoding - the encoding to use, null means platform default; lines - the lines to write, null entries produce blank lines; lineEnding - the line separator to use, null is system default
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 1.1

writeLines

public static void writeLines(File file,
                              String encoding,
                              Collection<?> lines,
                              String lineEnding,
                              boolean append)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the line ending will be used.

Parameters:: file - the file to write to; encoding - the encoding to use, null means platform default; lines - the lines to write, null entries produce blank lines; lineEnding - the line separator to use, null is system default; append - if true, then the lines will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error; UnsupportedEncodingException - if the encoding is not supported by the VM
Since:: 2.1

writeLines

public static void writeLines(File file,
                              Collection<?> lines,
                              String lineEnding)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the specified line ending will be used.

Parameters:: file - the file to write to; lines - the lines to write, null entries produce blank lines; lineEnding - the line separator to use, null is system default
Throws:: IOException - in case of an I/O error
Since:: 1.3

writeLines

public static void writeLines(File file,
                              Collection<?> lines,
                              String lineEnding,
                              boolean append)
                       throws IOException

Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the specified line ending will be used.

Parameters:: file - the file to write to; lines - the lines to write, null entries produce blank lines; lineEnding - the line separator to use, null is system default; append - if true, then the lines will be added to the end of the file rather than overwriting
Throws:: IOException - in case of an I/O error
Since:: 2.1

forceDelete

public static void forceDelete(File file)
                        throws IOException

Deletes a file. If file is a directory, delete it and all sub-directories.

The difference between File.delete() and this method are:

A directory to be deleted does not have to be empty.
You get exceptions when a file or directory cannot be deleted. (java.io.File methods returns a boolean)

Parameters:: file - file or directory to delete, must not be null
Throws:: NullPointerException - if the directory is null; FileNotFoundException - if the file was not found; IOException - in case deletion is unsuccessful

forceDeleteOnExit

public static void forceDeleteOnExit(File file)
                              throws IOException

Schedules a file to be deleted when JVM exits. If file is directory delete it and all sub-directories.

Parameters:: file - file or directory to delete, must not be null
Throws:: NullPointerException - if the file is null; IOException - in case deletion is unsuccessful

forceMkdir

public static void forceMkdir(File directory)
                       throws IOException

Makes a directory, including any necessary but nonexistent parent directories. If a file already exists with specified name but it is not a directory then an IOException is thrown. If the directory cannot be created (or does not already exist) then an IOException is thrown.

Parameters:: directory - directory to create, must not be null
Throws:: NullPointerException - if the directory is null; IOException - if the directory cannot be created or the file already exists but is not a directory

sizeOf

public static long sizeOf(File file)

Returns the size of the specified file or directory. If the provided File is a regular file, then the file's length is returned. If the argument is a directory, then the size of the directory is calculated recursively. If a directory or subdirectory is security restricted, its size will not be included.

Parameters:: file - the regular file or directory to return the size of (must not be null).
Returns:: the length of the file, or recursive size of the directory, provided (in bytes).
Throws:: NullPointerException - if the file is null; IllegalArgumentException - if the file does not exist.
Since:: 2.0

sizeOfAsBigInteger

public static BigInteger sizeOfAsBigInteger(File file)

Parameters:: file - the regular file or directory to return the size of (must not be null).
Returns:: the length of the file, or recursive size of the directory, provided (in bytes).
Throws:: NullPointerException - if the file is null; IllegalArgumentException - if the file does not exist.
Since:: 2.4

sizeOfDirectory

public static long sizeOfDirectory(File directory)

Counts the size of a directory recursively (sum of the length of all files).

Parameters:: directory - directory to inspect, must not be null
Returns:: size of directory in bytes, 0 if directory is security restricted, a negative number when the real total is greater than Long.MAX_VALUE.
Throws:: NullPointerException - if the directory is null

sizeOfDirectoryAsBigInteger

public static BigInteger sizeOfDirectoryAsBigInteger(File directory)

Counts the size of a directory recursively (sum of the length of all files).

Parameters:: directory - directory to inspect, must not be null
Returns:: size of directory in bytes, 0 if directory is security restricted.
Throws:: NullPointerException - if the directory is null
Since:: 2.4

isFileNewer

public static boolean isFileNewer(File file,
                                  File reference)

Tests if the specified File is newer than the reference File.

Parameters:: file - the File of which the modification date must be compared, must not be null; reference - the File of which the modification date is used, must not be null
Returns:: true if the File exists and has been modified more recently than the reference File
Throws:: IllegalArgumentException - if the file is null; IllegalArgumentException - if the reference file is null or doesn't exist

isFileNewer

public static boolean isFileNewer(File file,
                                  Date date)

Tests if the specified File is newer than the specified Date.

Parameters:: file - the File of which the modification date must be compared, must not be null; date - the date reference, must not be null
Returns:: true if the File exists and has been modified after the given Date.
Throws:: IllegalArgumentException - if the file is null; IllegalArgumentException - if the date is null

isFileNewer

public static boolean isFileNewer(File file,
                                  long timeMillis)

Tests if the specified File is newer than the specified time reference.

Parameters:: file - the File of which the modification date must be compared, must not be null; timeMillis - the time reference measured in milliseconds since the epoch (00:00:00 GMT, January 1, 1970)
Returns:: true if the File exists and has been modified after the given time reference.
Throws:: IllegalArgumentException - if the file is null

isFileOlder

public static boolean isFileOlder(File file,
                                  File reference)

Tests if the specified File is older than the reference File.

Parameters:: file - the File of which the modification date must be compared, must not be null; reference - the File of which the modification date is used, must not be null
Returns:: true if the File exists and has been modified before the reference File
Throws:: IllegalArgumentException - if the file is null; IllegalArgumentException - if the reference file is null or doesn't exist

isFileOlder

public static boolean isFileOlder(File file,
                                  Date date)

Tests if the specified File is older than the specified Date.

Parameters:: file - the File of which the modification date must be compared, must not be null; date - the date reference, must not be null
Returns:: true if the File exists and has been modified before the given Date.
Throws:: IllegalArgumentException - if the file is null; IllegalArgumentException - if the date is null

isFileOlder

public static boolean isFileOlder(File file,
                                  long timeMillis)

Tests if the specified File is older than the specified time reference.

Parameters:: file - the File of which the modification date must be compared, must not be null; timeMillis - the time reference measured in milliseconds since the epoch (00:00:00 GMT, January 1, 1970)
Returns:: true if the File exists and has been modified before the given time reference.
Throws:: IllegalArgumentException - if the file is null

checksumCRC32

public static long checksumCRC32(File file)
                          throws IOException

Computes the checksum of a file using the CRC32 checksum routine. The value of the checksum is returned.

Parameters:: file - the file to checksum, must not be null
Returns:: the checksum value
Throws:: NullPointerException - if the file or checksum is null; IllegalArgumentException - if the file is a directory; IOException - if an IO error occurs reading the file
Since:: 1.3

checksum

public static Checksum checksum(File file,
                                Checksum checksum)
                         throws IOException

Computes the checksum of a file using the specified checksum object. Multiple files may be checked using one Checksum instance if desired simply by reusing the same checksum object. For example:

   long csum = FileUtils.checksum(file, new CRC32()).getValue();

Parameters:: file - the file to checksum, must not be null; checksum - the checksum object to be used, must not be null
Returns:: the checksum specified, updated with the content of the file
Throws:: NullPointerException - if the file or checksum is null; IllegalArgumentException - if the file is a directory; IOException - if an IO error occurs reading the file
Since:: 1.3

moveDirectory

public static void moveDirectory(File srcDir,
                                 File destDir)
                          throws IOException

Moves a directory.

When the destination directory is on another file system, do a "copy and delete".

Parameters:: srcDir - the directory to be moved; destDir - the destination directory
Throws:: NullPointerException - if source or destination is null; FileExistsException - if the destination directory exists; IOException - if source or destination is invalid; IOException - if an IO error occurs moving the file
Since:: 1.4

moveDirectoryToDirectory

public static void moveDirectoryToDirectory(File src,
                                            File destDir,
                                            boolean createDestDir)
                                     throws IOException

Moves a directory to another directory.

Parameters:: src - the file to be moved; destDir - the destination file; createDestDir - If true create the destination directory, otherwise if false throw an IOException
Throws:: NullPointerException - if source or destination is null; FileExistsException - if the directory exists in the destination directory; IOException - if source or destination is invalid; IOException - if an IO error occurs moving the file
Since:: 1.4

moveFile

public static void moveFile(File srcFile,
                            File destFile)
                     throws IOException

Moves a file.

When the destination file is on another file system, do a "copy and delete".

Parameters:: srcFile - the file to be moved; destFile - the destination file
Throws:: NullPointerException - if source or destination is null; FileExistsException - if the destination file exists; IOException - if source or destination is invalid; IOException - if an IO error occurs moving the file
Since:: 1.4

moveFileToDirectory

public static void moveFileToDirectory(File srcFile,
                                       File destDir,
                                       boolean createDestDir)
                                throws IOException

Moves a file to a directory.

Parameters:: srcFile - the file to be moved; destDir - the destination file; createDestDir - If true create the destination directory, otherwise if false throw an IOException
Throws:: NullPointerException - if source or destination is null; FileExistsException - if the destination file exists; IOException - if source or destination is invalid; IOException - if an IO error occurs moving the file
Since:: 1.4

moveToDirectory

public static void moveToDirectory(File src,
                                   File destDir,
                                   boolean createDestDir)
                            throws IOException

Moves a file or directory to the destination directory.

When the destination is on another file system, do a "copy and delete".

Parameters:: src - the file or directory to be moved; destDir - the destination directory; createDestDir - If true create the destination directory, otherwise if false throw an IOException
Throws:: NullPointerException - if source or destination is null; FileExistsException - if the directory or file exists in the destination directory; IOException - if source or destination is invalid; IOException - if an IO error occurs moving the file
Since:: 1.4

isSymlink

public static boolean isSymlink(File file)
                         throws IOException

Determines whether the specified file is a Symbolic Link rather than an actual file.

Will not return true if there is a Symbolic Link anywhere in the path, only if the specific file is.

Note: the current implementation always returns false if the system is detected as Windows using FilenameUtils.isSystemWindows()

Parameters:: file - the file to check
Returns:: true if the file is a Symbolic Link
Throws:: IOException - if an IO error occurs while checking the file
Since:: 2.0

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FileUtils

getFile

getFile

getTempDirectoryPath

getTempDirectory

getUserDirectoryPath

getUserDirectory

openInputStream

openOutputStream

openOutputStream

byteCountToDisplaySize

byteCountToDisplaySize

touch

convertFileCollectionToFileArray

listFiles

listFilesAndDirs

iterateFiles

iterateFilesAndDirs

listFiles

iterateFiles

contentEquals

contentEqualsIgnoreEOL

toFile

toFiles

toURLs

copyFileToDirectory

copyFileToDirectory

copyFile

copyFile

copyFile

copyDirectoryToDirectory

copyDirectory

copyDirectory

copyDirectory

Example: Copy directories only

Example: Copy directories and txt files

copyDirectory

Example: Copy directories only

Example: Copy directories and txt files

copyURLToFile

copyURLToFile

copyInputStreamToFile

deleteDirectory

deleteQuietly

directoryContains

cleanDirectory

waitFor

readFileToString

readFileToString

readFileToString

readFileToByteArray

readLines

readLines

readLines

lineIterator

lineIterator

writeStringToFile

writeStringToFile

writeStringToFile

writeStringToFile

writeStringToFile

writeStringToFile

write

write

org.apache.commons.io
Class FileUtils