FileUtils (The Adobe AEM Quickstart and Web Application.)

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

```
public class FileUtils
extends java.lang.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
Note that a specific charset should be specified whenever possible. Relying on the platform default means that the code is Locale-dependent. Only use the default if the files are known to always use the platform default.

SecurityException are not documented in the Javadoc.

Origin of code: Excalibur, Alexandria, Commons-Utils

Field Summary

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

Constructor Summary

Constructors
Constructor and Description

FileUtils()
Deprecated.
Will be private in 3.0.

Constructors
Constructor and Description
`FileUtils()` Deprecated. Will be private in 3.0.

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static java.lang.String`	`byteCountToDisplaySize(java.math.BigInteger size)` Returns a human-readable version of the file size, where the input represents a specific number of bytes.
`static java.lang.String`	`byteCountToDisplaySize(long size)` Returns a human-readable version of the file size, where the input represents a specific number of bytes.
`static java.lang.String`	`byteCountToDisplaySize(java.lang.Number size)` Returns a human-readable version of the file size, where the input represents a specific number of bytes.
`static java.util.zip.Checksum`	`checksum(java.io.File file, java.util.zip.Checksum checksum)` Computes the checksum of a file using the specified checksum object.
`static long`	`checksumCRC32(java.io.File file)` Computes the checksum of a file using the CRC32 checksum routine.
`static void`	`cleanDirectory(java.io.File directory)` Cleans a directory without deleting it.
`static boolean`	`contentEquals(java.io.File file1, java.io.File file2)` Tests whether the contents of two files are equal.
`static boolean`	`contentEqualsIgnoreEOL(java.io.File file1, java.io.File file2, java.lang.String charsetName)` Compares the contents of two files to determine if they are equal or not.
`static java.io.File[]`	`convertFileCollectionToFileArray(java.util.Collection<java.io.File> files)` Converts a Collection containing java.io.File instances into array representation.
`static void`	`copyDirectory(java.io.File srcDir, java.io.File destDir)` Copies a whole directory to a new location preserving the file dates.
`static void`	`copyDirectory(java.io.File srcDir, java.io.File destDir, boolean preserveFileDate)` Copies a whole directory to a new location.
`static void`	`copyDirectory(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter)` Copies a filtered directory to a new location preserving the file dates.
`static void`	`copyDirectory(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter, boolean preserveFileDate)` Copies a filtered directory to a new location.
`static void`	`copyDirectory(java.io.File srcDir, java.io.File destDir, java.io.FileFilter fileFilter, boolean preserveFileDate, java.nio.file.CopyOption... copyOptions)` Copies a filtered directory to a new location.
`static void`	`copyDirectoryToDirectory(java.io.File sourceDir, java.io.File destinationDir)` Copies a directory to within another directory preserving the file dates.
`static void`	`copyFile(java.io.File srcFile, java.io.File destFile)` Copies a file to a new location preserving the file date.
`static void`	`copyFile(java.io.File srcFile, java.io.File destFile, boolean preserveFileDate)` Copies an existing file to a new file location.
`static void`	`copyFile(java.io.File srcFile, java.io.File destFile, boolean preserveFileDate, java.nio.file.CopyOption... copyOptions)` Copies a file to a new location.
`static void`	`copyFile(java.io.File srcFile, java.io.File destFile, java.nio.file.CopyOption... copyOptions)` Copies a file to a new location.
`static long`	`copyFile(java.io.File input, java.io.OutputStream output)` Copies bytes from a `File` to an `OutputStream`.
`static void`	`copyFileToDirectory(java.io.File srcFile, java.io.File destDir)` Copies a file to a directory preserving the file date.
`static void`	`copyFileToDirectory(java.io.File sourceFile, java.io.File destinationDir, boolean preserveFileDate)` Copies a file to a directory optionally preserving the file date.
`static void`	`copyInputStreamToFile(java.io.InputStream source, java.io.File destination)` Copies bytes from an `InputStream` `source` to a file `destination`.
`static void`	`copyToDirectory(java.io.File sourceFile, java.io.File destinationDir)` Copies a file or directory to within another directory preserving the file dates.
`static void`	`copyToDirectory(java.lang.Iterable<java.io.File> sourceIterable, java.io.File destinationDir)` Copies a files to a directory preserving each file's date.
`static void`	`copyToFile(java.io.InputStream inputStream, java.io.File file)` Copies bytes from an `InputStream` source to a `File` destination.
`static void`	`copyURLToFile(java.net.URL source, java.io.File destination)` Copies bytes from the URL `source` to a file `destination`.
`static void`	`copyURLToFile(java.net.URL source, java.io.File destination, int connectionTimeoutMillis, int readTimeoutMillis)` Copies bytes from the URL `source` to a file `destination`.
`static java.io.File`	`createParentDirectories(java.io.File file)` Creates all parent directories for a File object, including any necessary but nonexistent parent directories.
`static java.io.File`	`current()` Gets the current directory.
`static java.io.File`	`delete(java.io.File file)` Deletes the given File but throws an IOException if it cannot, unlike `File.delete()` which returns a boolean.
`static void`	`deleteDirectory(java.io.File directory)` Deletes a directory recursively.
`static boolean`	`deleteQuietly(java.io.File file)` Deletes a file, never throwing an exception.
`static boolean`	`directoryContains(java.io.File directory, java.io.File child)` Determines whether the `parent` directory contains the `child` element (a file or directory).
`static void`	`forceDelete(java.io.File file)` Deletes a file or directory.
`static void`	`forceDeleteOnExit(java.io.File file)` Schedules a file to be deleted when JVM exits.
`static void`	`forceMkdir(java.io.File directory)` Creates all directories for a File object, including any necessary but nonexistent parent directories.
`static void`	`forceMkdirParent(java.io.File file)` Calls `File.mkdirs()` and throws an `IOException` on failure.
`static java.io.File`	`getFile(java.io.File directory, java.lang.String... names)` Constructs a file from the set of name elements.
`static java.io.File`	`getFile(java.lang.String... names)` Constructs a file from the set of name elements.
`static java.io.File`	`getTempDirectory()` Returns a `File` representing the system temporary directory.
`static java.lang.String`	`getTempDirectoryPath()` Returns the path to the system temporary directory.
`static java.io.File`	`getUserDirectory()` Returns a `File` representing the user's home directory.
`static java.lang.String`	`getUserDirectoryPath()` Returns the path to the user's home directory.
`static boolean`	`isDirectory(java.io.File file, java.nio.file.LinkOption... options)` Tests whether the specified `File` is a directory or not.
`static boolean`	`isEmptyDirectory(java.io.File directory)` Tests whether the directory is empty.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate)` Tests if the specified `File` is newer than the specified `ChronoLocalDate` at the end of day.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate, java.time.LocalTime localTime)` Tests if the specified `File` is newer than the specified `ChronoLocalDate` at the specified time.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate, java.time.OffsetTime offsetTime)` Tests if the specified `File` is newer than the specified `ChronoLocalDate` at the specified `OffsetTime`.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime)` Tests if the specified `File` is newer than the specified `ChronoLocalDateTime` at the system-default time zone.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime, java.time.ZoneId zoneId)` Tests if the specified `File` is newer than the specified `ChronoLocalDateTime` at the specified `ZoneId`.
`static boolean`	`isFileNewer(java.io.File file, java.time.chrono.ChronoZonedDateTime<?> chronoZonedDateTime)` Tests if the specified `File` is newer than the specified `ChronoZonedDateTime`.
`static boolean`	`isFileNewer(java.io.File file, java.util.Date date)` Tests if the specified `File` is newer than the specified `Date`.
`static boolean`	`isFileNewer(java.io.File file, java.io.File reference)` Tests if the specified `File` is newer than the reference `File`.
`static boolean`	`isFileNewer(java.io.File file, java.nio.file.attribute.FileTime fileTime)` Tests if the specified `File` is newer than the specified `FileTime`.
`static boolean`	`isFileNewer(java.io.File file, java.time.Instant instant)` Tests if the specified `File` is newer than the specified `Instant`.
`static boolean`	`isFileNewer(java.io.File file, long timeMillis)` Tests if the specified `File` is newer than the specified time reference.
`static boolean`	`isFileNewer(java.io.File file, java.time.OffsetDateTime offsetDateTime)` Tests if the specified `File` is newer than the specified `OffsetDateTime`.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate)` Tests if the specified `File` is older than the specified `ChronoLocalDate` at the end of day.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate, java.time.LocalTime localTime)` Tests if the specified `File` is older than the specified `ChronoLocalDate` at the specified `LocalTime`.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoLocalDate chronoLocalDate, java.time.OffsetTime offsetTime)` Tests if the specified `File` is older than the specified `ChronoLocalDate` at the specified `OffsetTime`.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime)` Tests if the specified `File` is older than the specified `ChronoLocalDateTime` at the system-default time zone.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime, java.time.ZoneId zoneId)` Tests if the specified `File` is older than the specified `ChronoLocalDateTime` at the specified `ZoneId`.
`static boolean`	`isFileOlder(java.io.File file, java.time.chrono.ChronoZonedDateTime<?> chronoZonedDateTime)` Tests if the specified `File` is older than the specified `ChronoZonedDateTime`.
`static boolean`	`isFileOlder(java.io.File file, java.util.Date date)` Tests if the specified `File` is older than the specified `Date`.
`static boolean`	`isFileOlder(java.io.File file, java.io.File reference)` Tests if the specified `File` is older than the reference `File`.
`static boolean`	`isFileOlder(java.io.File file, java.nio.file.attribute.FileTime fileTime)` Tests if the specified `File` is older than the specified `FileTime`.
`static boolean`	`isFileOlder(java.io.File file, java.time.Instant instant)` Tests if the specified `File` is older than the specified `Instant`.
`static boolean`	`isFileOlder(java.io.File file, long timeMillis)` Tests if the specified `File` is older than the specified time reference.
`static boolean`	`isFileOlder(java.io.File file, java.time.OffsetDateTime offsetDateTime)` Tests if the specified `File` is older than the specified `OffsetDateTime`.
`static boolean`	`isRegularFile(java.io.File file, java.nio.file.LinkOption... options)` Tests whether the specified `File` is a regular file or not.
`static boolean`	`isSymlink(java.io.File file)` Tests whether the specified file is a symbolic link rather than an actual file.
`static java.util.Iterator<java.io.File>`	`iterateFiles(java.io.File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Iterates over the files in given directory (and optionally its subdirectories).
`static java.util.Iterator<java.io.File>`	`iterateFiles(java.io.File directory, java.lang.String[] extensions, boolean recursive)` Iterates over the files in a given directory (and optionally its subdirectories) which match an array of extensions.
`static java.util.Iterator<java.io.File>`	`iterateFilesAndDirs(java.io.File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Iterates over the files in given directory (and optionally its subdirectories).
`static long`	`lastModified(java.io.File file)` Returns the last modification time in milliseconds via `Files.getLastModifiedTime(Path, LinkOption...)`.
`static java.nio.file.attribute.FileTime`	`lastModifiedFileTime(java.io.File file)` Returns the last modification `FileTime` via `Files.getLastModifiedTime(Path, LinkOption...)`.
`static long`	`lastModifiedUnchecked(java.io.File file)` Returns the last modification time in milliseconds via `Files.getLastModifiedTime(Path, LinkOption...)`.
`static LineIterator`	`lineIterator(java.io.File file)` Returns an Iterator for the lines in a `File` using the default encoding for the VM.
`static LineIterator`	`lineIterator(java.io.File file, java.lang.String charsetName)` Returns an Iterator for the lines in a `File`.
`static java.util.Collection<java.io.File>`	`listFiles(java.io.File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Finds files within a given directory (and optionally its subdirectories).
`static java.util.Collection<java.io.File>`	`listFiles(java.io.File directory, java.lang.String[] extensions, boolean recursive)` Finds files within a given directory (and optionally its subdirectories) which match an array of extensions.
`static java.util.Collection<java.io.File>`	`listFilesAndDirs(java.io.File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)` Finds files within a given directory (and optionally its subdirectories).
`static void`	`moveDirectory(java.io.File srcDir, java.io.File destDir)` Moves a directory.
`static void`	`moveDirectoryToDirectory(java.io.File source, java.io.File destDir, boolean createDestDir)` Moves a directory to another directory.
`static void`	`moveFile(java.io.File srcFile, java.io.File destFile)` Moves a file preserving attributes.
`static void`	`moveFile(java.io.File srcFile, java.io.File destFile, java.nio.file.CopyOption... copyOptions)` Moves a file.
`static void`	`moveFileToDirectory(java.io.File srcFile, java.io.File destDir, boolean createDestDir)` Moves a file to a directory.
`static void`	`moveToDirectory(java.io.File src, java.io.File destDir, boolean createDestDir)` Moves a file or directory to a destination directory.
`static java.io.OutputStream`	`newOutputStream(java.io.File file, boolean append)` Creates a new OutputStream by opening or creating a file, returning an output stream that may be used to write bytes to the file.
`static java.io.FileInputStream`	`openInputStream(java.io.File file)` Opens a `FileInputStream` for the specified file, providing better error messages than simply calling `new FileInputStream(file)`.
`static java.io.FileOutputStream`	`openOutputStream(java.io.File file)` Opens a `FileOutputStream` for the specified file, checking and creating the parent directory if it does not exist.
`static java.io.FileOutputStream`	`openOutputStream(java.io.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(java.io.File file)` Reads the contents of a file into a byte array.
`static java.lang.String`	`readFileToString(java.io.File file)` Deprecated. 2.5 use `readFileToString(File, Charset)` instead (and specify the appropriate encoding)
`static java.lang.String`	`readFileToString(java.io.File file, java.nio.charset.Charset charsetName)` Reads the contents of a file into a String.
`static java.lang.String`	`readFileToString(java.io.File file, java.lang.String charsetName)` Reads the contents of a file into a String.
`static java.util.List<java.lang.String>`	`readLines(java.io.File file)` Deprecated. 2.5 use `readLines(File, Charset)` instead (and specify the appropriate encoding)
`static java.util.List<java.lang.String>`	`readLines(java.io.File file, java.nio.charset.Charset charset)` Reads the contents of a file line by line to a List of Strings.
`static java.util.List<java.lang.String>`	`readLines(java.io.File file, java.lang.String charsetName)` Reads the contents of a file line by line to a List of Strings.
`static long`	`sizeOf(java.io.File file)` Returns the size of the specified file or directory.
`static java.math.BigInteger`	`sizeOfAsBigInteger(java.io.File file)` Returns the size of the specified file or directory.
`static long`	`sizeOfDirectory(java.io.File directory)` Counts the size of a directory recursively (sum of the length of all files).
`static java.math.BigInteger`	`sizeOfDirectoryAsBigInteger(java.io.File directory)` Counts the size of a directory recursively (sum of the length of all files).
`static java.util.stream.Stream<java.io.File>`	`streamFiles(java.io.File directory, boolean recursive, java.lang.String... extensions)` Streams over the files in a given directory (and optionally its subdirectories) which match an array of extensions.
`static java.io.File`	`toFile(java.net.URL url)` Converts from a `URL` to a `File`.
`static java.io.File[]`	`toFiles(java.net.URL... urls)` Converts each of an array of `URL` to a `File`.
`static void`	`touch(java.io.File file)` Implements behavior similar to the Unix "touch" utility.
`static java.net.URL[]`	`toURLs(java.io.File... files)` Converts each of an array of `File` to a `URL`.
`static boolean`	`waitFor(java.io.File file, int seconds)` Waits for the file system to propagate a file creation, with a timeout.
`static void`	`write(java.io.File file, java.lang.CharSequence data)` Deprecated. 2.5 use `write(File, CharSequence, Charset)` instead (and specify the appropriate encoding)
`static void`	`write(java.io.File file, java.lang.CharSequence data, boolean append)` Deprecated. 2.5 use `write(File, CharSequence, Charset, boolean)` instead (and specify the appropriate encoding)
`static void`	`write(java.io.File file, java.lang.CharSequence data, java.nio.charset.Charset charset)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(java.io.File file, java.lang.CharSequence data, java.nio.charset.Charset charset, boolean append)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(java.io.File file, java.lang.CharSequence data, java.lang.String charsetName)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`write(java.io.File file, java.lang.CharSequence data, java.lang.String charsetName, boolean append)` Writes a CharSequence to a file creating the file if it does not exist.
`static void`	`writeByteArrayToFile(java.io.File file, byte[] data)` Writes a byte array to a file creating the file if it does not exist.
`static void`	`writeByteArrayToFile(java.io.File file, byte[] data, boolean append)` Writes a byte array to a file creating the file if it does not exist.
`static void`	`writeByteArrayToFile(java.io.File file, byte[] data, int off, int len)` Writes `len` bytes from the specified byte array starting at offset `off` to a file, creating the file if it does not exist.
`static void`	`writeByteArrayToFile(java.io.File file, byte[] data, int off, int len, boolean append)` Writes `len` bytes from the specified byte array starting at offset `off` to a file, creating the file if it does not exist.
`static void`	`writeLines(java.io.File file, java.util.Collection<?> lines)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.util.Collection<?> lines, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.util.Collection<?> lines, java.lang.String lineEnding)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.util.Collection<?> lines, java.lang.String lineEnding, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.lang.String charsetName, java.util.Collection<?> lines)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.lang.String charsetName, java.util.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(java.io.File file, java.lang.String charsetName, java.util.Collection<?> lines, java.lang.String lineEnding)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeLines(java.io.File file, java.lang.String charsetName, java.util.Collection<?> lines, java.lang.String lineEnding, boolean append)` Writes the `toString()` value of each item in a collection to the specified `File` line by line.
`static void`	`writeStringToFile(java.io.File file, java.lang.String data)` Deprecated. 2.5 use `writeStringToFile(File, String, Charset)` instead (and specify the appropriate encoding)
`static void`	`writeStringToFile(java.io.File file, java.lang.String data, boolean append)` Deprecated. 2.5 use `writeStringToFile(File, String, Charset, boolean)` instead (and specify the appropriate encoding)
`static void`	`writeStringToFile(java.io.File file, java.lang.String data, java.nio.charset.Charset charset)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(java.io.File file, java.lang.String data, java.nio.charset.Charset charset, boolean append)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(java.io.File file, java.lang.String data, java.lang.String charsetName)` Writes a String to a file creating the file if it does not exist.
`static void`	`writeStringToFile(java.io.File file, java.lang.String data, java.lang.String charsetName, boolean append)` Writes a String to a file creating the file if it does not exist.

Methods inherited from class java.lang.Object
equals, 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 java.math.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 java.math.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 java.math.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 java.math.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 java.math.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 java.math.BigInteger ONE_EB_BI
```
    The number of bytes in an exabyte.
    
    Since:
    
    2.4
  - ONE_ZB
```
public static final java.math.BigInteger ONE_ZB
```
    The number of bytes in a zettabyte.
  - ONE_YB
```
public static final java.math.BigInteger ONE_YB
```
    The number of bytes in a yottabyte.
  - EMPTY_FILE_ARRAY
```
public static final java.io.File[] EMPTY_FILE_ARRAY
```
    An empty array of type File.
- Constructor Detail
  - FileUtils
```
@Deprecated
public FileUtils()
```
    Deprecated. Will be private in 3.0.
    
    Instances should NOT be constructed in standard programming.
- Method Detail
  - byteCountToDisplaySize
```
public static java.lang.String byteCountToDisplaySize(java.math.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)
    
    Throws:
    
    java.lang.NullPointerException - if the given BigInteger is null.
    
    Since:
    
    2.4
    
    See Also:
    
    IO-226 - should the rounding be changed?
  - byteCountToDisplaySize
```
public static java.lang.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?
  - byteCountToDisplaySize
```
public static java.lang.String byteCountToDisplaySize(java.lang.Number 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:
    
    2.12.0
    
    See Also:
    
    IO-226 - should the rounding be changed?
  - checksum
```
public static java.util.zip.Checksum checksum(java.io.File file,
                                              java.util.zip.Checksum checksum)
                                       throws java.io.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 checksum = 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:
    
    java.lang.NullPointerException - if the given File is null.
    
    java.lang.NullPointerException - if the given Checksum is null.
    
    java.lang.IllegalArgumentException - if the given File does not exist or is not a file.
    
    java.io.IOException - if an IO error occurs reading the file.
    
    Since:
    
    1.3
  - checksumCRC32
```
public static long checksumCRC32(java.io.File file)
                          throws java.io.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:
    
    java.lang.NullPointerException - if the given File is null.
    
    java.lang.IllegalArgumentException - if the given File does not exist or is not a file.
    
    java.io.IOException - if an IO error occurs reading the file.
    
    Since:
    
    1.3
  - cleanDirectory
```
public static void cleanDirectory(java.io.File directory)
                           throws java.io.IOException
```
    Cleans a directory without deleting it.
    
    Parameters:
    
    directory - directory to clean
    
    Throws:
    
    java.lang.NullPointerException - if the given File is null.
    
    java.lang.IllegalArgumentException - if directory does not exist or is not a directory.
    
    java.io.IOException - if an I/O error occurs.
    
    See Also:
    
    forceDelete(File)
  - contentEquals
```
public static boolean contentEquals(java.io.File file1,
                                    java.io.File file2)
                             throws java.io.IOException
```
    Tests whether the contents of two files are equal.
    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:
    
    java.lang.IllegalArgumentException - when an input is not a file.
    
    java.io.IOException - If an I/O error occurs.
    
    See Also:
    
    PathUtils.fileContentEquals(Path,Path,java.nio.file.LinkOption[],java.nio.file.OpenOption...)
  - contentEqualsIgnoreEOL
```
public static boolean contentEqualsIgnoreEOL(java.io.File file1,
                                             java.io.File file2,
                                             java.lang.String charsetName)
                                      throws java.io.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 name of the requested charset. 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:
    
    java.lang.IllegalArgumentException - when an input is not a file.
    
    java.io.IOException - in case of an I/O error.
    
    java.nio.charset.UnsupportedCharsetException - If the named charset is unavailable (unchecked exception).
    
    Since:
    
    2.2
    
    See Also:
    
    IOUtils.contentEqualsIgnoreEOL(Reader, Reader)
  - convertFileCollectionToFileArray
```
public static java.io.File[] convertFileCollectionToFileArray(java.util.Collection<java.io.File> files)
```
    Converts a Collection containing java.io.File instances 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
  - copyDirectory
```
public static void copyDirectory(java.io.File srcDir,
                                 java.io.File destDir)
                          throws java.io.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.
    
    Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    srcDir - an existing directory to copy, must not be null.
    
    destDir - the new directory, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.1
  - copyDirectory
```
public static void copyDirectory(java.io.File srcDir,
                                 java.io.File destDir,
                                 boolean preserveFileDate)
                          throws java.io.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, the methods throws IOException.
    
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.1
  - copyDirectory
```
public static void copyDirectory(java.io.File srcDir,
                                 java.io.File destDir,
                                 java.io.FileFilter filter)
                          throws java.io.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.
    
    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, the methods throws IOException.
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.4
  - copyDirectory
```
public static void copyDirectory(java.io.File srcDir,
                                 java.io.File destDir,
                                 java.io.FileFilter filter,
                                 boolean preserveFileDate)
                          throws java.io.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.
    
    Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.4
  - copyDirectory
```
public static void copyDirectory(java.io.File srcDir,
                                 java.io.File destDir,
                                 java.io.FileFilter fileFilter,
                                 boolean preserveFileDate,
                                 java.nio.file.CopyOption... copyOptions)
                          throws java.io.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.
    
    Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    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
    
    fileFilter - 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
    
    copyOptions - options specifying how the copy should be done, for example StandardCopyOption.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    2.8.0
  - copyDirectoryToDirectory
```
public static void copyDirectoryToDirectory(java.io.File sourceDir,
                                            java.io.File destinationDir)
                                     throws java.io.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: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    sourceDir - an existing directory to copy, must not be null.
    
    destinationDir - the directory to place the copy in, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.2
  - copyFile
```
public static void copyFile(java.io.File srcFile,
                            java.io.File destFile)
                     throws java.io.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.
    
    Note: This method tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    srcFile - an existing file to copy, must not be null.
    
    destFile - the new file, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    java.io.IOException - if the output file length is not the same as the input file length after the copy completes.
    
    See Also:
    
    copyFileToDirectory(File, File), copyFile(File, File, boolean)
  - copyFile
```
public static void copyFile(java.io.File srcFile,
                            java.io.File destFile,
                            boolean preserveFileDate)
                     throws java.io.IOException
```
    Copies an existing file to a new file location.
    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.
    
    Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    java.io.IOException - if the output file length is not the same as the input file length after the copy completes
    
    See Also:
    
    copyFile(File, File, boolean, CopyOption...)
  - copyFile
```
public static void copyFile(java.io.File srcFile,
                            java.io.File destFile,
                            boolean preserveFileDate,
                            java.nio.file.CopyOption... copyOptions)
                     throws java.io.IOException
```
    Copies a file to a new location.
    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, you can overwrite it with StandardCopyOption.REPLACE_EXISTING.
    
    Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    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.
    
    copyOptions - options specifying how the copy should be done, for example StandardCopyOption..
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.lang.IllegalArgumentException - if source is not a file.
    
    java.io.IOException - if the output file length is not the same as the input file length after the copy completes.
    
    java.io.IOException - if an I/O error occurs, or setting the last-modified time didn't succeed.
    
    Since:
    
    2.8.0
    
    See Also:
    
    copyFileToDirectory(File, File, boolean)
  - copyFile
```
public static void copyFile(java.io.File srcFile,
                            java.io.File destFile,
                            java.nio.file.CopyOption... copyOptions)
                     throws java.io.IOException
```
    Copies a file to a new location.
    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, you can overwrite it if you use StandardCopyOption.REPLACE_EXISTING.
    
    Parameters:
    
    srcFile - an existing file to copy, must not be null.
    
    destFile - the new file, must not be null.
    
    copyOptions - options specifying how the copy should be done, for example StandardCopyOption..
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.lang.IllegalArgumentException - if source is not a file.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.9.0
    
    See Also:
    
    StandardCopyOption
  - copyFile
```
public static long copyFile(java.io.File input,
                            java.io.OutputStream output)
                     throws java.io.IOException
```
    Copies 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.
    
    output - the OutputStream to write.
    
    Returns:
    
    the number of bytes copied
    
    Throws:
    
    java.lang.NullPointerException - if the File is null.
    
    java.lang.NullPointerException - if the OutputStream is null.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.1
  - copyFileToDirectory
```
public static void copyFileToDirectory(java.io.File srcFile,
                                       java.io.File destDir)
                                throws java.io.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 BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    srcFile - an existing file to copy, must not be null.
    
    destDir - the directory to place the copy in, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    See Also:
    
    copyFile(File, File, boolean)
  - copyFileToDirectory
```
public static void copyFileToDirectory(java.io.File sourceFile,
                                       java.io.File destinationDir,
                                       boolean preserveFileDate)
                                throws java.io.IOException
```
    Copies a file to a directory optionally 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: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    sourceFile - an existing file to copy, must not be null.
    
    destinationDir - 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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    java.io.IOException - if the output file length is not the same as the input file length after the copy completes.
    
    Since:
    
    1.3
    
    See Also:
    
    copyFile(File, File, CopyOption...)
  - copyInputStreamToFile
```
public static void copyInputStreamToFile(java.io.InputStream source,
                                         java.io.File destination)
                                  throws java.io.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.
    The source stream is closed.
    
    See copyToFile(InputStream, File) for a method that does not close the input stream.
    
    Parameters:
    
    source - the InputStream to copy bytes from, must not be null, will be closed
    
    destination - the non-directory File to write bytes to (possibly overwriting), must not be null
    
    Throws:
    
    java.io.IOException - if destination is a directory
    
    java.io.IOException - if destination cannot be written
    
    java.io.IOException - if destination needs creating but can't be
    
    java.io.IOException - if an IO error occurs during copying
    
    Since:
    
    2.0
  - copyToDirectory
```
public static void copyToDirectory(java.io.File sourceFile,
                                   java.io.File destinationDir)
                            throws java.io.IOException
```
    Copies a file or directory to within another directory preserving the file dates.
    This method copies the source file or directory, along 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: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    sourceFile - an existing file or directory to copy, must not be null.
    
    destinationDir - the directory to place the copy in, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    2.6
    
    See Also:
    
    copyDirectoryToDirectory(File, File), copyFileToDirectory(File, File)
  - copyToDirectory
```
public static void copyToDirectory(java.lang.Iterable<java.io.File> sourceIterable,
                                   java.io.File destinationDir)
                            throws java.io.IOException
```
    Copies a files to a directory preserving each file's date.
    This method copies the contents of the specified source files 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: Setting preserveFileDate to true tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime), however it is not guaranteed that the operation will succeed. If the modification operation fails it will fallback to File.setLastModified(long) and if that fails, the methods throws IOException.
    
    Parameters:
    
    sourceIterable - existing files to copy, must not be null.
    
    destinationDir - the directory to place the copies in, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    2.6
    
    See Also:
    
    copyFileToDirectory(File, File)
  - copyToFile
```
public static void copyToFile(java.io.InputStream inputStream,
                              java.io.File file)
                       throws java.io.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. The source stream is left open, e.g. for use with ZipInputStream. See copyInputStreamToFile(InputStream, File) for a method that closes the input stream.
    
    Parameters:
    
    inputStream - the InputStream to copy bytes from, must not be null
    
    file - the non-directory File to write bytes to (possibly overwriting), must not be null
    
    Throws:
    
    java.lang.NullPointerException - if the InputStream is null.
    
    java.lang.NullPointerException - if the File is null.
    
    java.lang.IllegalArgumentException - if the file object is a directory.
    
    java.lang.IllegalArgumentException - if the file is not writable.
    
    java.io.IOException - if the directories could not be created.
    
    java.io.IOException - if an IO error occurs during copying.
    
    Since:
    
    2.5
  - copyURLToFile
```
public static void copyURLToFile(java.net.URL source,
                                 java.io.File destination)
                          throws java.io.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:
    
    java.io.IOException - if source URL cannot be opened
    
    java.io.IOException - if destination is a directory
    
    java.io.IOException - if destination cannot be written
    
    java.io.IOException - if destination needs creating but can't be
    
    java.io.IOException - if an IO error occurs during copying
  - copyURLToFile
```
public static void copyURLToFile(java.net.URL source,
                                 java.io.File destination,
                                 int connectionTimeoutMillis,
                                 int readTimeoutMillis)
                          throws java.io.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
    
    connectionTimeoutMillis - the number of milliseconds until this method will time out if no connection could be established to the source
    
    readTimeoutMillis - the number of milliseconds until this method will time out if no data could be read from the source
    
    Throws:
    
    java.io.IOException - if source URL cannot be opened
    
    java.io.IOException - if destination is a directory
    
    java.io.IOException - if destination cannot be written
    
    java.io.IOException - if destination needs creating but can't be
    
    java.io.IOException - if an IO error occurs during copying
    
    Since:
    
    2.0
  - createParentDirectories
```
public static java.io.File createParentDirectories(java.io.File file)
                                            throws java.io.IOException
```
    Creates all parent directories for a File object, including any necessary but nonexistent parent directories. If a parent directory already exists or is null, nothing happens.
    
    Parameters:
    
    file - the File that may need parents, may be null.
    
    Returns:
    
    The parent directory, or null if the given File does have a parent.
    
    Throws:
    
    java.io.IOException - if the directory was not created along with all its parent directories.
    
    java.lang.SecurityException - See File.mkdirs().
    
    Since:
    
    2.9.0
  - current
```
public static java.io.File current()
```
    Gets the current directory.
    
    Returns:
    
    the current directory.
    
    Since:
    
    2.12.0
  - delete
```
public static java.io.File delete(java.io.File file)
                           throws java.io.IOException
```
    Deletes the given File but throws an IOException if it cannot, unlike File.delete() which returns a boolean.
    
    Parameters:
    
    file - The file to delete.
    
    Returns:
    
    the given file.
    
    Throws:
    
    java.lang.NullPointerException - if the parameter is null
    
    java.io.IOException - if the file cannot be deleted.
    
    Since:
    
    2.9.0
    
    See Also:
    
    File.delete()
  - deleteDirectory
```
public static void deleteDirectory(java.io.File directory)
                            throws java.io.IOException
```
    Deletes a directory recursively.
    
    Parameters:
    
    directory - directory to delete
    
    Throws:
    
    java.io.IOException - in case deletion is unsuccessful
    
    java.lang.NullPointerException - if the parameter is null
    
    java.lang.IllegalArgumentException - if directory is not a directory
  - deleteQuietly
```
public static boolean deleteQuietly(java.io.File file)
```
    Deletes a file, never throwing an exception. If file is a directory, delete it and all subdirectories.
    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(java.io.File directory,
                                        java.io.File child)
                                 throws java.io.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:
    
    java.io.IOException - if an IO error occurs while checking the files.
    
    java.lang.NullPointerException - if the given File is null.
    
    java.lang.IllegalArgumentException - if the given File does not exist or is not a directory.
    
    Since:
    
    2.2
    
    See Also:
    
    FilenameUtils.directoryContains(String, String)
  - forceDelete
```
public static void forceDelete(java.io.File file)
                        throws java.io.IOException
```
    Deletes a file or directory. For a directory, delete it and all subdirectories.
    The difference between File.delete() and this method are:
    - The directory does not have to be empty.
    - You get an exception when a file or directory cannot be deleted.
    Parameters:
    
    file - file or directory to delete, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if the file is null.
    
    java.io.FileNotFoundException - if the file was not found.
    
    java.io.IOException - in case deletion is unsuccessful.
  - forceDeleteOnExit
```
public static void forceDeleteOnExit(java.io.File file)
                              throws java.io.IOException
```
    Schedules a file to be deleted when JVM exits. If file is directory delete it and all subdirectories.
    
    Parameters:
    
    file - file or directory to delete, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if the file is null.
    
    java.io.IOException - in case deletion is unsuccessful.
  - forceMkdir
```
public static void forceMkdir(java.io.File directory)
                       throws java.io.IOException
```
    Creates all directories for a File object, including any necessary but nonexistent parent directories. If the directory already exists or is null, nothing happens.
    Calls File.mkdirs() and throws an IOException on failure.
    
    Parameters:
    
    directory - the receiver for mkdirs(). If the directory already exists or is null, nothing happens.
    
    Throws:
    
    java.io.IOException - if the directory was not created along with all its parent directories.
    
    java.io.IOException - if the given file object is not a directory.
    
    java.lang.SecurityException - See File.mkdirs().
    
    See Also:
    
    File.mkdirs()
  - forceMkdirParent
```
public static void forceMkdirParent(java.io.File file)
                             throws java.io.IOException
```
    Calls File.mkdirs() and throws an IOException on failure.
    Creates all directories for a File object, including any necessary but nonexistent parent directories. If the directory already exists or is null, nothing happens.
    
    Parameters:
    
    file - file with parents to create, must not be null.
    
    Throws:
    
    java.lang.NullPointerException - if the file is null.
    
    java.io.IOException - if the directory was not created along with all its parent directories.
    
    java.io.IOException - if the given file object is not a directory.
    
    java.lang.SecurityException - See File.mkdirs().
    
    Since:
    
    2.5
    
    See Also:
    
    File.mkdirs()
  - getFile
```
public static java.io.File getFile(java.io.File directory,
                                   java.lang.String... names)
```
    Constructs a file from the set of name elements.
    
    Parameters:
    
    directory - the parent directory.
    
    names - the name elements.
    
    Returns:
    
    the new file.
    
    Since:
    
    2.1
  - getFile
```
public static java.io.File getFile(java.lang.String... names)
```
    Constructs a file from the set of name elements.
    
    Parameters:
    
    names - the name elements.
    
    Returns:
    
    the file.
    
    Since:
    
    2.1
  - getTempDirectory
```
public static java.io.File getTempDirectory()
```
    Returns a File representing the system temporary directory.
    
    Returns:
    
    the system temporary directory.
    
    Since:
    
    2.0
  - getTempDirectoryPath
```
public static java.lang.String getTempDirectoryPath()
```
    Returns the path to the system temporary directory.
    
    Returns:
    
    the path to the system temporary directory.
    
    Since:
    
    2.0
  - getUserDirectory
```
public static java.io.File getUserDirectory()
```
    Returns a File representing the user's home directory.
    
    Returns:
    
    the user's home directory.
    
    Since:
    
    2.0
  - getUserDirectoryPath
```
public static java.lang.String getUserDirectoryPath()
```
    Returns the path to the user's home directory.
    
    Returns:
    
    the path to the user's home directory.
    
    Since:
    
    2.0
  - isDirectory
```
public static boolean isDirectory(java.io.File file,
                                  java.nio.file.LinkOption... options)
```
    Tests whether the specified File is a directory or not. Implemented as a null-safe delegate to Files.isDirectory(Path path, LinkOption... options).
    
    Parameters:
    
    file - the path to the file.
    
    options - options indicating how symbolic links are handled
    
    Returns:
    
    true if the file is a directory; false if the path is null, the file does not exist, is not a directory, or it cannot be determined if the file is a directory or not.
    
    Throws:
    
    java.lang.SecurityException - In the case of the default provider, and a security manager is installed, the checkRead method is invoked to check read access to the directory.
    
    Since:
    
    2.9.0
  - isEmptyDirectory
```
public static boolean isEmptyDirectory(java.io.File directory)
                                throws java.io.IOException
```
    Tests whether the directory is empty.
    
    Parameters:
    
    directory - the directory to query.
    
    Returns:
    
    whether the directory is empty.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    java.nio.file.NotDirectoryException - if the file could not otherwise be opened because it is not a directory (optional specific exception).
    
    Since:
    
    2.9.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate)
```
    Tests if the specified File is newer than the specified ChronoLocalDate at the end of day.
    Note: The input date is assumed to be in the system default time-zone with the time part set to the current time. To use a non-default time-zone use the method isFileNewer(file, chronoLocalDate.atTime(LocalTime.now(zoneId)), zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDate - the date reference.
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDate at the current time.
    
    Throws:
    
    java.lang.NullPointerException - if the file or local date is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate,
                                  java.time.LocalTime localTime)
```
    Tests if the specified File is newer than the specified ChronoLocalDate at the specified time.
    Note: The input date and time are assumed to be in the system default time-zone. To use a non-default time-zone use the method isFileNewer(file, chronoLocalDate.atTime(localTime), zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDate - the date reference.
    
    localTime - the time reference.
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDate at the given time.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date or zone ID is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate,
                                  java.time.OffsetTime offsetTime)
```
    Tests if the specified File is newer than the specified ChronoLocalDate at the specified OffsetTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared
    
    chronoLocalDate - the date reference
    
    offsetTime - the time reference
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDate at the given OffsetTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date or zone ID is null
    
    Since:
    
    2.12.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime)
```
    Tests if the specified File is newer than the specified ChronoLocalDateTime at the system-default time zone.
    Note: The input date and time is assumed to be in the system default time-zone. To use a non-default time-zone use the method isFileNewer(file, chronoLocalDateTime, zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDateTime - the date reference.
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDateTime at the system-default time zone.
    
    Throws:
    
    java.lang.NullPointerException - if the file or local date time is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime,
                                  java.time.ZoneId zoneId)
```
    Tests if the specified File is newer than the specified ChronoLocalDateTime at the specified ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDateTime - the date reference.
    
    zoneId - the time zone.
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDateTime at the given ZoneId.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date time or zone ID is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.chrono.ChronoZonedDateTime<?> chronoZonedDateTime)
```
    Tests if the specified File is newer than the specified ChronoZonedDateTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoZonedDateTime - the date reference.
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoZonedDateTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file or zoned date time is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.util.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.
    
    date - the date reference.
    
    Returns:
    
    true if the File exists and has been modified after the given Date.
    
    Throws:
    
    java.lang.NullPointerException - if the file or date is null.
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.io.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.
    
    reference - the File of which the modification date is used.
    
    Returns:
    
    true if the File exists and has been modified more recently than the reference File.
    
    Throws:
    
    java.lang.NullPointerException - if the file or reference file is null.
    
    java.lang.IllegalArgumentException - if the reference file doesn't exist.
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.nio.file.attribute.FileTime fileTime)
                           throws java.io.IOException
```
    Tests if the specified File is newer than the specified FileTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    fileTime - the file time reference.
    
    Returns:
    
    true if the File exists and has been modified after the given FileTime.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    java.lang.NullPointerException - if the file or local date is null.
    
    Since:
    
    2.12.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.Instant instant)
```
    Tests if the specified File is newer than the specified Instant.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    instant - the date reference.
    
    Returns:
    
    true if the File exists and has been modified after the given Instant.
    
    Throws:
    
    java.lang.NullPointerException - if the file or instant is null.
    
    Since:
    
    2.8.0
  - isFileNewer
```
public static boolean isFileNewer(java.io.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.
    
    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:
    
    java.lang.NullPointerException - if the file is null.
  - isFileNewer
```
public static boolean isFileNewer(java.io.File file,
                                  java.time.OffsetDateTime offsetDateTime)
```
    Tests if the specified File is newer than the specified OffsetDateTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared
    
    offsetDateTime - the date reference
    
    Returns:
    
    true if the File exists and has been modified before the given OffsetDateTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file or zoned date time is null
    
    Since:
    
    2.12.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate)
```
    Tests if the specified File is older than the specified ChronoLocalDate at the end of day.
    Note: The input date is assumed to be in the system default time-zone with the time part set to the current time. To use a non-default time-zone use the method isFileOlder(file, chronoLocalDate.atTime(LocalTime.now(zoneId)), zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDate - the date reference.
    
    Returns:
    
    true if the File exists and has been modified before the given ChronoLocalDate at the current time.
    
    Throws:
    
    java.lang.NullPointerException - if the file or local date is null.
    
    Since:
    
    2.8.0
    
    See Also:
    
    ZoneId.systemDefault(), LocalTime.now()
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate,
                                  java.time.LocalTime localTime)
```
    Tests if the specified File is older than the specified ChronoLocalDate at the specified LocalTime.
    Note: The input date and time are assumed to be in the system default time-zone. To use a non-default time-zone use the method isFileOlder(file, chronoLocalDate.atTime(localTime), zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDate - the date reference.
    
    localTime - the time reference.
    
    Returns:
    
    true if the File exists and has been modified before the given ChronoLocalDate at the specified time.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date or local time is null.
    
    Since:
    
    2.8.0
    
    See Also:
    
    ZoneId.systemDefault()
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoLocalDate chronoLocalDate,
                                  java.time.OffsetTime offsetTime)
```
    Tests if the specified File is older than the specified ChronoLocalDate at the specified OffsetTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared
    
    chronoLocalDate - the date reference
    
    offsetTime - the time reference
    
    Returns:
    
    true if the File exists and has been modified after the given ChronoLocalDate at the given OffsetTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date or zone ID is null
    
    Since:
    
    2.12.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime)
```
    Tests if the specified File is older than the specified ChronoLocalDateTime at the system-default time zone.
    Note: The input date and time is assumed to be in the system default time-zone. To use a non-default time-zone use the method isFileOlder(file, chronoLocalDateTime, zoneId) where zoneId is a valid ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDateTime - the date reference.
    
    Returns:
    
    true if the File exists and has been modified before the given ChronoLocalDateTime at the system-default time zone.
    
    Throws:
    
    java.lang.NullPointerException - if the file or local date time is null.
    
    Since:
    
    2.8.0
    
    See Also:
    
    ZoneId.systemDefault()
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoLocalDateTime<?> chronoLocalDateTime,
                                  java.time.ZoneId zoneId)
```
    Tests if the specified File is older than the specified ChronoLocalDateTime at the specified ZoneId.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoLocalDateTime - the date reference.
    
    zoneId - the time zone.
    
    Returns:
    
    true if the File exists and has been modified before the given ChronoLocalDateTime at the given ZoneId.
    
    Throws:
    
    java.lang.NullPointerException - if the file, local date time or zone ID is null.
    
    Since:
    
    2.8.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.chrono.ChronoZonedDateTime<?> chronoZonedDateTime)
```
    Tests if the specified File is older than the specified ChronoZonedDateTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    chronoZonedDateTime - the date reference.
    
    Returns:
    
    true if the File exists and has been modified before the given ChronoZonedDateTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file or zoned date time is null.
    
    Since:
    
    2.8.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.util.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.
    
    date - the date reference.
    
    Returns:
    
    true if the File exists and has been modified before the given Date.
    
    Throws:
    
    java.lang.NullPointerException - if the file or date is null.
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.io.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.
    
    reference - the File of which the modification date is used.
    
    Returns:
    
    true if the File exists and has been modified before the reference File.
    
    Throws:
    
    java.lang.NullPointerException - if the file or reference file is null.
    
    java.lang.IllegalArgumentException - if the reference file doesn't exist.
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.nio.file.attribute.FileTime fileTime)
                           throws java.io.IOException
```
    Tests if the specified File is older than the specified FileTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    fileTime - the file time reference.
    
    Returns:
    
    true if the File exists and has been modified before the given FileTime.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    java.lang.NullPointerException - if the file or local date is null.
    
    Since:
    
    2.12.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.Instant instant)
```
    Tests if the specified File is older than the specified Instant.
    
    Parameters:
    
    file - the File of which the modification date must be compared.
    
    instant - the date reference.
    
    Returns:
    
    true if the File exists and has been modified before the given Instant.
    
    Throws:
    
    java.lang.NullPointerException - if the file or instant is null.
    
    Since:
    
    2.8.0
  - isFileOlder
```
public static boolean isFileOlder(java.io.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.
    
    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:
    
    java.lang.NullPointerException - if the file is null.
  - isFileOlder
```
public static boolean isFileOlder(java.io.File file,
                                  java.time.OffsetDateTime offsetDateTime)
```
    Tests if the specified File is older than the specified OffsetDateTime.
    
    Parameters:
    
    file - the File of which the modification date must be compared
    
    offsetDateTime - the date reference
    
    Returns:
    
    true if the File exists and has been modified before the given OffsetDateTime.
    
    Throws:
    
    java.lang.NullPointerException - if the file or zoned date time is null
    
    Since:
    
    2.12.0
  - isRegularFile
```
public static boolean isRegularFile(java.io.File file,
                                    java.nio.file.LinkOption... options)
```
    Tests whether the specified File is a regular file or not. Implemented as a null-safe delegate to Files.isRegularFile(Path path, LinkOption... options).
    
    Parameters:
    
    file - the path to the file.
    
    options - options indicating how symbolic links are handled
    
    Returns:
    
    true if the file is a regular file; false if the path is null, the file does not exist, is not a regular file, or it cannot be determined if the file is a regular file or not.
    
    Throws:
    
    java.lang.SecurityException - In the case of the default provider, and a security manager is installed, the checkRead method is invoked to check read access to the directory.
    
    Since:
    
    2.9.0
  - isSymlink
```
public static boolean isSymlink(java.io.File file)
```
    Tests whether the specified file is a symbolic link rather than an actual file.
    This method delegates to Files.isSymbolicLink(Path path)
    
    Parameters:
    
    file - the file to test.
    
    Returns:
    
    true if the file is a symbolic link, see Files.isSymbolicLink(Path path).
    
    Since:
    
    2.0
    
    See Also:
    
    Files.isSymbolicLink(Path)
  - iterateFiles
```
public static java.util.Iterator<java.io.File> iterateFiles(java.io.File directory,
                                                            IOFileFilter fileFilter,
                                                            IOFileFilter dirFilter)
```
    Iterates over the files in given directory (and optionally its subdirectories).
    The resulting iterator MUST be consumed in its entirety in order to close its underlying stream.
    
    All files found are filtered by an IOFileFilter.
    
    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
  - iterateFiles
```
public static java.util.Iterator<java.io.File> iterateFiles(java.io.File directory,
                                                            java.lang.String[] extensions,
                                                            boolean recursive)
```
    Iterates over the files in a given directory (and optionally its subdirectories) which match an array of extensions.
    The resulting iterator MUST be consumed in its entirety in order to close its underlying stream.
    
    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
  - iterateFilesAndDirs
```
public static java.util.Iterator<java.io.File> iterateFilesAndDirs(java.io.File directory,
                                                                   IOFileFilter fileFilter,
                                                                   IOFileFilter dirFilter)
```
    Iterates over the files in given directory (and optionally its subdirectories).
    The resulting iterator MUST be consumed in its entirety in order to close its underlying stream.
    
    All files found are filtered by an IOFileFilter.
    
    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
  - lastModified
```
public static long lastModified(java.io.File file)
                         throws java.io.IOException
```
    Returns the last modification time in milliseconds via Files.getLastModifiedTime(Path, LinkOption...).
    For the best precision, use lastModifiedFileTime(File).
    
    Use this method to avoid issues with File.lastModified() like JDK-8177809 where File.lastModified() is losing milliseconds (always ends in 000). This bug exists in OpenJDK 8 and 9, and is fixed in 10.
    
    Parameters:
    
    file - The File to query.
    
    Returns:
    
    See FileTime.toMillis().
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.9.0
  - lastModifiedFileTime
```
public static java.nio.file.attribute.FileTime lastModifiedFileTime(java.io.File file)
                                                             throws java.io.IOException
```
    Returns the last modification FileTime via Files.getLastModifiedTime(Path, LinkOption...).
    Use this method to avoid issues with File.lastModified() like JDK-8177809 where File.lastModified() is losing milliseconds (always ends in 000). This bug exists in OpenJDK 8 and 9, and is fixed in 10.
    
    Parameters:
    
    file - The File to query.
    
    Returns:
    
    See Files.getLastModifiedTime(Path, LinkOption...).
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.12.0
  - lastModifiedUnchecked
```
public static long lastModifiedUnchecked(java.io.File file)
```
    Returns the last modification time in milliseconds via Files.getLastModifiedTime(Path, LinkOption...).
    For the best precision, use lastModifiedFileTime(File).
    
    Use this method to avoid issues with File.lastModified() like JDK-8177809 where File.lastModified() is losing milliseconds (always ends in 000). This bug exists in OpenJDK 8 and 9, and is fixed in 10.
    
    Parameters:
    
    file - The File to query.
    
    Returns:
    
    See FileTime.toMillis().
    
    Throws:
    
    java.io.UncheckedIOException - if an I/O error occurs.
    
    Since:
    
    2.9.0
  - lineIterator
```
public static LineIterator lineIterator(java.io.File file)
                                 throws java.io.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:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    1.3
    
    See Also:
    
    lineIterator(File, String)
  - lineIterator
```
public static LineIterator lineIterator(java.io.File file,
                                        java.lang.String charsetName)
                                 throws java.io.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 using a try-with-resources block or calling the LineIterator.close() method.
    
    The recommended usage pattern is:
```
 LineIterator it = FileUtils.lineIterator(file, StandardCharsets.UTF_8.name());
 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
    
    charsetName - the name of the requested charset, null means platform default
    
    Returns:
    
    a LineIterator for lines in the file, never null; MUST be closed by the caller.
    
    Throws:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    1.2
  - listFiles
```
public static java.util.Collection<java.io.File> listFiles(java.io.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. Must not be null, use TrueFileFilter.INSTANCE to match all files in selected directories.
    
    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:
    
    a collection of java.io.File with the matching files
    
    See Also:
    
    FileFilterUtils, NameFileFilter
  - listFiles
```
public static java.util.Collection<java.io.File> listFiles(java.io.File directory,
                                                           java.lang.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:
    
    a collection of java.io.File with the matching files
  - listFilesAndDirs
```
public static java.util.Collection<java.io.File> listFilesAndDirs(java.io.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 starting directory and any subdirectories that match the directory filter.
    
    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:
    
    a collection of java.io.File with the matching files
    
    Since:
    
    2.2
    
    See Also:
    
    listFiles(java.io.File, java.io.FileFilter), FileFilterUtils, NameFileFilter
  - moveDirectory
```
public static void moveDirectory(java.io.File srcDir,
                                 java.io.File destDir)
                          throws java.io.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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.4
  - moveDirectoryToDirectory
```
public static void moveDirectoryToDirectory(java.io.File source,
                                            java.io.File destDir,
                                            boolean createDestDir)
                                     throws java.io.IOException
```
    Moves a directory to another directory.
    If createDestDir is true, creates all destination parent directories, including any necessary but nonexistent parent directories.
    
    Parameters:
    
    source - the file to be moved.
    
    destDir - the destination file.
    
    createDestDir - If true create the destination directory, otherwise if false throw an IOException.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    java.lang.IllegalArgumentException - if the source or destination is invalid.
    
    java.io.FileNotFoundException - if the source does not exist.
    
    java.io.IOException - if the directory was not created along with all its parent directories, if enabled.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    java.lang.SecurityException - See File.mkdirs().
    
    Since:
    
    1.4
  - moveFile
```
public static void moveFile(java.io.File srcFile,
                            java.io.File destFile)
                     throws java.io.IOException
```
    Moves a file preserving attributes.
    Shorthand for moveFile(srcFile, destFile, StandardCopyOption.COPY_ATTRIBUTES).
    
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    FileExistsException - if the destination file exists.
    
    java.io.FileNotFoundException - if the source file does not exist.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs.
    
    Since:
    
    1.4
  - moveFile
```
public static void moveFile(java.io.File srcFile,
                            java.io.File destFile,
                            java.nio.file.CopyOption... copyOptions)
                     throws java.io.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.
    
    copyOptions - Copy options.
    
    Throws:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    FileExistsException - if the destination file exists.
    
    java.io.FileNotFoundException - if the source file does not exist.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    2.9.0
  - moveFileToDirectory
```
public static void moveFileToDirectory(java.io.File srcFile,
                                       java.io.File destDir,
                                       boolean createDestDir)
                                throws java.io.IOException
```
    Moves a file to a directory.
    If createDestDir is true, creates all destination parent directories, including any necessary but nonexistent parent directories.
    
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    FileExistsException - if the destination file exists.
    
    java.io.FileNotFoundException - if the source file does not exist.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if the directory was not created along with all its parent directories, if enabled.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    java.lang.SecurityException - See File.mkdirs().
    
    Since:
    
    1.4
  - moveToDirectory
```
public static void moveToDirectory(java.io.File src,
                                   java.io.File destDir,
                                   boolean createDestDir)
                            throws java.io.IOException
```
    Moves a file or directory to a destination directory.
    If createDestDir is true, creates all destination parent directories, including any necessary but nonexistent parent directories.
    
    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:
    
    java.lang.NullPointerException - if any of the given Files are null.
    
    FileExistsException - if the directory or file exists in the destination directory.
    
    java.io.FileNotFoundException - if the source file does not exist.
    
    java.io.IOException - if source or destination is invalid.
    
    java.io.IOException - if an error occurs or setting the last-modified time didn't succeed.
    
    Since:
    
    1.4
  - newOutputStream
```
public static java.io.OutputStream newOutputStream(java.io.File file,
                                                   boolean append)
                                            throws java.io.IOException
```
    Creates a new OutputStream by opening or creating a file, returning an output stream that may be used to write bytes to the file.
    
    Parameters:
    
    append - Whether or not to append.
    
    file - the File.
    
    Returns:
    
    a new OutputStream.
    
    Throws:
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.12.0
    
    See Also:
    
    PathUtils.newOutputStream(Path, boolean)
  - openInputStream
```
public static java.io.FileInputStream openInputStream(java.io.File file)
                                               throws java.io.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:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - See FileNotFoundException above, FileNotFoundException is a subclass of IOException.
    
    Since:
    
    1.3
  - openOutputStream
```
public static java.io.FileOutputStream openOutputStream(java.io.File file)
                                                 throws java.io.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:
    
    java.lang.NullPointerException - if the file object is null.
    
    java.lang.IllegalArgumentException - if the file object is a directory
    
    java.lang.IllegalArgumentException - if the file is not writable.
    
    java.io.IOException - if the directories could not be created.
    
    Since:
    
    1.3
  - openOutputStream
```
public static java.io.FileOutputStream openOutputStream(java.io.File file,
                                                        boolean append)
                                                 throws java.io.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
    
    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:
    
    java.lang.NullPointerException - if the file object is null.
    
    java.lang.IllegalArgumentException - if the file object is a directory
    
    java.lang.IllegalArgumentException - if the file is not writable.
    
    java.io.IOException - if the directories could not be created.
    
    Since:
    
    2.1
  - readFileToByteArray
```
public static byte[] readFileToByteArray(java.io.File file)
                                  throws java.io.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:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    1.1
  - readFileToString
```
@Deprecated
public static java.lang.String readFileToString(java.io.File file)
                                                     throws java.io.IOException
```
    Deprecated. 2.5 use readFileToString(File, Charset) instead (and specify the appropriate encoding)
    
    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:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    1.3.1
  - readFileToString
```
public static java.lang.String readFileToString(java.io.File file,
                                                java.nio.charset.Charset charsetName)
                                         throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    Returns:
    
    the file contents, never null
    
    Throws:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.3
  - readFileToString
```
public static java.lang.String readFileToString(java.io.File file,
                                                java.lang.String charsetName)
                                         throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    Returns:
    
    the file contents, never null
    
    Throws:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    java.nio.charset.UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the named charset is unavailable.
    
    Since:
    
    2.3
  - readLines
```
@Deprecated
public static java.util.List<java.lang.String> readLines(java.io.File file)
                                                              throws java.io.IOException
```
    Deprecated. 2.5 use readLines(File, Charset) instead (and specify the appropriate encoding)
    
    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:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    1.3
  - readLines
```
public static java.util.List<java.lang.String> readLines(java.io.File file,
                                                         java.nio.charset.Charset charset)
                                                  throws java.io.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
    
    charset - the charset to use, null means platform default
    
    Returns:
    
    the list of Strings representing each line in the file, never null
    
    Throws:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    Since:
    
    2.3
  - readLines
```
public static java.util.List<java.lang.String> readLines(java.io.File file,
                                                         java.lang.String charsetName)
                                                  throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    Returns:
    
    the list of Strings representing each line in the file, never null
    
    Throws:
    
    java.lang.NullPointerException - if file is null.
    
    java.io.FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.
    
    java.io.IOException - if an I/O error occurs.
    
    java.nio.charset.UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the named charset is unavailable.
    
    Since:
    
    1.1
  - sizeOf
```
public static long sizeOf(java.io.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.
    Note that overflow is not detected, and the return value may be negative if overflow occurs. See sizeOfAsBigInteger(File) for an alternative method that does not overflow.
    
    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:
    
    java.lang.NullPointerException - if the file is null.
    
    java.lang.IllegalArgumentException - if the file does not exist.
    
    java.io.UncheckedIOException - if an IO error occurs.
    
    Since:
    
    2.0
  - sizeOfAsBigInteger
```
public static java.math.BigInteger sizeOfAsBigInteger(java.io.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:
    
    java.lang.NullPointerException - if the file is null.
    
    java.lang.IllegalArgumentException - if the file does not exist.
    
    java.io.UncheckedIOException - if an IO error occurs.
    
    Since:
    
    2.4
  - sizeOfDirectory
```
public static long sizeOfDirectory(java.io.File directory)
```
    Counts the size of a directory recursively (sum of the length of all files).
    Note that overflow is not detected, and the return value may be negative if overflow occurs. See sizeOfDirectoryAsBigInteger(File) for an alternative method that does not overflow.
    
    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:
    
    java.lang.NullPointerException - if the directory is null.
    
    java.io.UncheckedIOException - if an IO error occurs.
  - sizeOfDirectoryAsBigInteger
```
public static java.math.BigInteger sizeOfDirectoryAsBigInteger(java.io.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:
    
    java.lang.NullPointerException - if the directory is null.
    
    java.io.UncheckedIOException - if an IO error occurs.
    
    Since:
    
    2.4
  - streamFiles
```
public static java.util.stream.Stream<java.io.File> streamFiles(java.io.File directory,
                                                                boolean recursive,
                                                                java.lang.String... extensions)
                                                         throws java.io.IOException
```
    Streams over the files in a given directory (and optionally its subdirectories) which match an array of extensions.
    
    Parameters:
    
    directory - the directory to search in
    
    recursive - if true all subdirectories are searched as well
    
    extensions - an array of extensions, ex. {"java","xml"}. If this parameter is null, all files are returned.
    
    Returns:
    
    an iterator of java.io.File with the matching files
    
    Throws:
    
    java.io.IOException - if an I/O error is thrown when accessing the starting file.
    
    Since:
    
    2.9.0
  - toFile
```
public static java.io.File toFile(java.net.URL url)
```
    Converts 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 java.io.File[] toFiles(java.net.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:
    
    java.lang.IllegalArgumentException - if any file is not a URL file
    
    java.lang.IllegalArgumentException - if any file is incorrectly encoded
    
    Since:
    
    1.1
  - touch
```
public static void touch(java.io.File file)
                  throws java.io.IOException
```
    Implements behavior similar to the Unix "touch" utility. Creates a new file with size 0, or, if the file exists, just updates the file's modified 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:
    
    java.lang.NullPointerException - if the parameter is null.
    
    java.io.IOException - if setting the last-modified time failed or an I/O problem occurs.
  - toURLs
```
public static java.net.URL[] toURLs(java.io.File... files)
                             throws java.io.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:
    
    java.io.IOException - if a file cannot be converted
    
    java.lang.NullPointerException - if the parameter is null
  - waitFor
```
public static boolean waitFor(java.io.File file,
                              int seconds)
```
    Waits for the file system to propagate a file creation, with a timeout.
    This method repeatedly tests Files.exists(Path, LinkOption...) 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:
    
    java.lang.NullPointerException - if the file is null
  - write
```
@Deprecated
public static void write(java.io.File file,
                                     java.lang.CharSequence data)
                              throws java.io.IOException
```
    Deprecated. 2.5 use write(File, CharSequence, Charset) instead (and specify the appropriate encoding)
    
    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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.0
  - write
```
@Deprecated
public static void write(java.io.File file,
                                     java.lang.CharSequence data,
                                     boolean append)
                              throws java.io.IOException
```
    Deprecated. 2.5 use write(File, CharSequence, Charset, boolean) instead (and specify the appropriate encoding)
    
    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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.1
  - write
```
public static void write(java.io.File file,
                         java.lang.CharSequence data,
                         java.nio.charset.Charset charset)
                  throws java.io.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
    
    charset - the name of the requested charset, null means platform default
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.3
  - write
```
public static void write(java.io.File file,
                         java.lang.CharSequence data,
                         java.nio.charset.Charset charset,
                         boolean append)
                  throws java.io.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
    
    charset - the charset 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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.3
  - write
```
public static void write(java.io.File file,
                         java.lang.CharSequence data,
                         java.lang.String charsetName)
                  throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    2.0
  - write
```
public static void write(java.io.File file,
                         java.lang.CharSequence data,
                         java.lang.String charsetName,
                         boolean append)
                  throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    append - if true, then the data will be added to the end of the file rather than overwriting
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.nio.charset.UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported by the VM
    
    Since:
    
    2.1
  - writeByteArrayToFile
```
public static void writeByteArrayToFile(java.io.File file,
                                        byte[] data)
                                 throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    1.1
  - writeByteArrayToFile
```
public static void writeByteArrayToFile(java.io.File file,
                                        byte[] data,
                                        boolean append)
                                 throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.1
  - writeByteArrayToFile
```
public static void writeByteArrayToFile(java.io.File file,
                                        byte[] data,
                                        int off,
                                        int len)
                                 throws java.io.IOException
```
    Writes len bytes from the specified byte array starting at offset off 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
    
    off - the start offset in the data
    
    len - the number of bytes to write
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.5
  - writeByteArrayToFile
```
public static void writeByteArrayToFile(java.io.File file,
                                        byte[] data,
                                        int off,
                                        int len,
                                        boolean append)
                                 throws java.io.IOException
```
    Writes len bytes from the specified byte array starting at offset off 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
    
    off - the start offset in the data
    
    len - the number of bytes to write
    
    append - if true, then bytes will be added to the end of the file rather than overwriting
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.5
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.util.Collection<?> lines)
                       throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    1.3
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.util.Collection<?> lines,
                              boolean append)
                       throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.1
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.util.Collection<?> lines,
                              java.lang.String lineEnding)
                       throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    1.3
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.util.Collection<?> lines,
                              java.lang.String lineEnding,
                              boolean append)
                       throws java.io.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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.1
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.lang.String charsetName,
                              java.util.Collection<?> lines)
                       throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    lines - the lines to write, null entries produce blank lines
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    1.1
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.lang.String charsetName,
                              java.util.Collection<?> lines,
                              boolean append)
                       throws java.io.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
    
    charsetName - the name of the requested charset, 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:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    2.1
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.lang.String charsetName,
                              java.util.Collection<?> lines,
                              java.lang.String lineEnding)
                       throws java.io.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
    
    charsetName - the name of the requested charset, 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:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    1.1
  - writeLines
```
public static void writeLines(java.io.File file,
                              java.lang.String charsetName,
                              java.util.Collection<?> lines,
                              java.lang.String lineEnding,
                              boolean append)
                       throws java.io.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
    
    charsetName - the name of the requested charset, 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:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    2.1
  - writeStringToFile
```
@Deprecated
public static void writeStringToFile(java.io.File file,
                                                 java.lang.String data)
                                          throws java.io.IOException
```
    Deprecated. 2.5 use writeStringToFile(File, String, Charset) instead (and specify the appropriate encoding)
    
    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:
    
    java.io.IOException - in case of an I/O error
  - writeStringToFile
```
@Deprecated
public static void writeStringToFile(java.io.File file,
                                                 java.lang.String data,
                                                 boolean append)
                                          throws java.io.IOException
```
    Deprecated. 2.5 use writeStringToFile(File, String, Charset, boolean) instead (and specify the appropriate encoding)
    
    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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.1
  - writeStringToFile
```
public static void writeStringToFile(java.io.File file,
                                     java.lang.String data,
                                     java.nio.charset.Charset charset)
                              throws java.io.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
    
    charset - the charset to use, null means platform default
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
    
    Since:
    
    2.4
  - writeStringToFile
```
public static void writeStringToFile(java.io.File file,
                                     java.lang.String data,
                                     java.nio.charset.Charset charset,
                                     boolean append)
                              throws java.io.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
    
    charset - the charset 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:
    
    java.io.IOException - in case of an I/O error
    
    Since:
    
    2.3
  - writeStringToFile
```
public static void writeStringToFile(java.io.File file,
                                     java.lang.String data,
                                     java.lang.String charsetName)
                              throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.io.UnsupportedEncodingException - if the encoding is not supported by the VM
  - writeStringToFile
```
public static void writeStringToFile(java.io.File file,
                                     java.lang.String data,
                                     java.lang.String charsetName,
                                     boolean append)
                              throws java.io.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
    
    charsetName - the name of the requested charset, null means platform default
    
    append - if true, then the String will be added to the end of the file rather than overwriting
    
    Throws:
    
    java.io.IOException - in case of an I/O error
    
    java.nio.charset.UnsupportedCharsetException - thrown instead of .UnsupportedEncodingException in version 2.2 if the encoding is not supported by the VM
    
    Since:
    
    2.1

Class FileUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ONE_KB

ONE_KB_BI

ONE_MB

ONE_MB_BI

ONE_GB

ONE_GB_BI

ONE_TB

ONE_TB_BI

ONE_PB

ONE_PB_BI

ONE_EB

ONE_EB_BI

ONE_ZB

ONE_YB

EMPTY_FILE_ARRAY

Constructor Detail

FileUtils

Method Detail

byteCountToDisplaySize

byteCountToDisplaySize

byteCountToDisplaySize

checksum

checksumCRC32

cleanDirectory

contentEquals

contentEqualsIgnoreEOL

convertFileCollectionToFileArray

copyDirectory

copyDirectory

copyDirectory

copyDirectory

copyDirectory

copyDirectoryToDirectory

copyFile

copyFile

copyFile

copyFile

copyFile

copyFileToDirectory

copyFileToDirectory

copyInputStreamToFile

copyToDirectory

copyToDirectory

copyToFile

copyURLToFile

copyURLToFile

createParentDirectories

current

delete

deleteDirectory

deleteQuietly

directoryContains

forceDelete

forceDeleteOnExit

forceMkdir

forceMkdirParent

getFile

getFile

getTempDirectory

getTempDirectoryPath

getUserDirectory

getUserDirectoryPath

isDirectory

isEmptyDirectory

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer

isFileNewer