Package org.apache.commons.io

Class FileUtils

java.lang.Object
org.apache.commons.io.FileUtils
public class FileUtils extends Object
General file manipulation utilities.

Facilities are provided in the following areas:

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

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.

Provenance: Excalibur, Alexandria, Commons-Utils

  • Field Details

  • Constructor Details

    • FileUtils

      @Deprecated public FileUtils()
      Deprecated.
      TODO Make private in 3.0.
      Instances should NOT be constructed in standard programming.

  • Method Details

    • byteCountToDisplaySize

      public static String byteCountToDisplaySize(BigInteger size)
      Returns a human-readable version of the file size, where the input represents a specific number of bytes.

      If the size is over 1GB, the size is returned as the number of whole GB, 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:
      NullPointerException - if the given BigInteger is null.
      Since:
      2.4
      See Also:

    • byteCountToDisplaySize

      public static String byteCountToDisplaySize(long size)
      Returns a human-readable version of the file size, where the input represents a specific number of bytes.

      If the size is over 1GB, the size is returned as the number of whole GB, 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:

    • byteCountToDisplaySize

      public static String byteCountToDisplaySize(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, 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:

    • checksum

      public static Checksum checksum(File file, Checksum checksum) throws IOException
      Computes the checksum of a file using the specified checksum object. Multiple files may be checked using one Checksum instance if desired simply by reusing the same checksum object. For example: 
       long 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:
      NullPointerException - if the given File is null.
      NullPointerException - if the given Checksum is null.
      IllegalArgumentException - if the given File is not a file.
      FileNotFoundException - if the file does not exist
      IOException - if an IO error occurs reading the file.
      Since:
      1.3

    • checksumCRC32

      public static long checksumCRC32(File file) throws IOException
      Computes the checksum of a file using the CRC32 checksum routine. The value of the checksum is returned.
      Parameters:
      file - the file to checksum, must not be null
      Returns:
      the checksum value
      Throws:
      NullPointerException - if the file is null.
      IllegalArgumentException - if the file does not exist or is not a file.
      IOException - if an IO error occurs reading the file.
      Since:
      1.3

    • cleanDirectory

      public static void cleanDirectory(File directory) throws IOException
      Cleans a directory without deleting it.
      Parameters:
      directory - directory to clean
      Throws:
      NullPointerException - if the given File is null.
      IllegalArgumentException - if the directory does not exist or is not a directory.
      IOException - if an I/O error occurs.
      See Also:

    • contentEquals

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

      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:
      IllegalArgumentException - when an input is not a file.
      IOException - If an I/O error occurs.
      See Also:

    • contentEqualsIgnoreEOL

      public static boolean contentEqualsIgnoreEOL(File file1, File file2, String charsetName) throws IOException
      Compares the contents of two files to determine if they are equal or not.

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

      Parameters:
      file1 - the first file
      file2 - the second file
      charsetName - the 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:
      IllegalArgumentException - when an input is not a file.
      IOException - in case of an I/O error.
      UnsupportedCharsetException - If the named charset is unavailable (unchecked exception).
      Since:
      2.2
      See Also:

    • convertFileCollectionToFileArray

      public static File[] convertFileCollectionToFileArray(Collection<File> files)
      Converts a Collection containing File instances into array representation. This is to account for the difference between File.listFiles() and FileUtils.listFiles().
      Parameters:
      files - a Collection containing File instances
      Returns:
      an array of File

    • copyDirectory

      public static void copyDirectory(File srcDir, File destDir) throws IOException
      Copies a whole directory to a new location, preserving the file dates.

      This method copies the specified directory and all its child directories and files to the specified destination. The destination is the new location and name of the directory. That is, copying /home/bar to /tmp/bang copies the contents of /home/bar into /tmp/bang. It does not create /tmp/bang/bar.

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

      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 falls back to File.setLastModified(long). If that fails, the method throws IOException.

      Symbolic links in the source directory are copied to new symbolic links in the destination directory that point to the original target. The target of the link is not copied unless it is also under the source directory. Even if it is under the source directory, the new symbolic link in the destination points to the original target in the source directory, not to the newly created copy of the target.

      Parameters:
      srcDir - an existing directory to copy, must not be null.
      destDir - the new directory, must not be null.
      Throws:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if srcDir exists but is not a directory, the source and the destination directory are the same
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs, the destination is not writable, or setting the last-modified time didn't succeed
      Since:
      1.1

    • copyDirectory

      public static void copyDirectory(File srcDir, File destDir, boolean preserveFileDate) throws IOException
      Copies a whole directory to a new location.

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

      The destination directory is created if it does not exist. If the destination directory does 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 method 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:
      IllegalArgumentException - if srcDir exists but is not a directory, or the source and the destination directory are the same
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs, the destination is not writable, or setting the last-modified time didn't succeed
      Since:
      1.1

    • copyDirectory

      public static void copyDirectory(File srcDir, File destDir, FileFilter filter) throws IOException
      Copies a filtered directory to a new location preserving the file dates.

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

      The destination directory is created if it does not exist. If the destination directory does 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 method 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.INSTANCE, txtSuffixFilter);

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

 // Copy using the filter
 FileUtils.copyDirectory(srcDir, destDir, filter);
      Parameters:
      srcDir - an existing directory to copy, must not be null.
      destDir - the new directory, must not be null.
      filter - the filter to apply, null means copy all directories and files should be the same as the original.
      Throws:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if srcDir exists but is not a directory, or the source and the destination directory are the same
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs, the destination is not writable, or setting the last-modified time didn't succeed
      Since:
      1.4

    • copyDirectory

      public static void copyDirectory(File srcDir, File destDir, FileFilter filter, boolean preserveFileDate) throws IOException
      Copies a filtered directory to a new location.

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

      The destination directory is created if it does not exist. If the destination directory does 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 falls back to File.setLastModified(long). If that fails, the method 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.INSTANCE, txtSuffixFilter);

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

 // Copy using the filter
 FileUtils.copyDirectory(srcDir, destDir, filter, false);
      Parameters:
      srcDir - an existing directory to copy, must not be null.
      destDir - the new directory, must not be null.
      filter - the filter to apply, null means copy all directories and files.
      preserveFileDate - true if the file date of the copy should be the same as the original.
      Throws:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if srcDir exists but is not a directory, the source and the destination directory are the same, or the destination is not writable
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      1.4

    • copyDirectory

      public static void copyDirectory(File srcDir, File destDir, FileFilter fileFilter, boolean preserveFileDate, CopyOption... copyOptions) throws IOException
      Copies a filtered directory to a new location.

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

      The destination directory is created if it does not exist. If the destination directory does 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 falls back to File.setLastModified(long). If that fails, the method 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.INSTANCE, 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:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if srcDir exists but is not a directory, or the source and the destination directory are the same
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs, the destination is not writable, or setting the last-modified time didn't succeed
      Since:
      2.8.0

    • copyDirectoryToDirectory

      public static void copyDirectoryToDirectory(File sourceDir, File destinationDir) throws IOException
      Copies a directory to within another directory preserving the file dates.

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

      The destination directory is created if it does not exist. If the destination directory does 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 falls back to File.setLastModified(long) and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if the source or destination is invalid.
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs, the destination is not writable, or setting the last-modified time didn't succeed
      Since:
      1.2

    • copyFile

      public static void copyFile(File srcFile, File destFile) throws IOException
      Copies a file to a new location preserving the file date.

      This method copies the contents of the specified source file to the specified destination file. The directory holding the destination file is created if it does not exist. If the destination file exists, then this method overwrites it. A symbolic link is resolved before copying so the new file is not a link.

      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 falls back to File.setLastModified(long), and if that fails, the method throws IOException.

      Parameters:
      srcFile - an existing file to copy, must not be null.
      destFile - the new file, must not be null.
      Throws:
      NullPointerException - if any of the given Files are null.
      IOException - if source or destination is invalid.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      IOException - if the output file length is not the same as the input file length after the copy completes.
      See Also:

    • copyFile

      public static void copyFile(File srcFile, File destFile, boolean preserveFileDate) throws 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 overwrites it. A symbolic link is resolved before copying so the new file is not a link.

      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 falls back to File.setLastModified(long), and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IOException - if source or destination is invalid.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      IOException - if the output file length is not the same as the input file length after the copy completes
      See Also:

    • copyFile

      public static void copyFile(File srcFile, File destFile, boolean preserveFileDate, CopyOption... copyOptions) throws IOException
      Copies the contents of 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.

      By default, a symbolic link is resolved before copying so the new file is not a link. To copy symbolic links as links, you can pass LinkOption.NO_FOLLOW_LINKS as the last argument.

      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 falls back to File.setLastModified(long), and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      FileNotFoundException - if the source does not exist.
      IllegalArgumentException - if srcFile or destFile is not a file
      IOException - if the output file length is not the same as the input file length after the copy completes.
      IOException - if an I/O error occurs, setting the last-modified time didn't succeed, or the destination is not writable
      Since:
      2.8.0
      See Also:

    • copyFile

      public static void copyFile(File srcFile, File destFile, CopyOption... copyOptions) throws 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:
      NullPointerException - if any of the given Files are null.
      FileNotFoundException - if the source does not exist.
      IllegalArgumentException - if source is not a file.
      IOException - if an I/O error occurs.
      Since:
      2.9.0
      See Also:

    • copyFile

      public static long copyFile(File input, OutputStream output) throws 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:
      NullPointerException - if the File is null.
      NullPointerException - if the OutputStream is null.
      IOException - if an I/O error occurs.
      Since:
      2.1

    • copyFileToDirectory

      public static void copyFileToDirectory(File srcFile, File destDir) throws IOException
      Copies a file to a directory preserving the file date.

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

      Note: This method tries to preserve the file's last modified date/times using BasicFileAttributeView.setTimes(FileTime, FileTime, FileTime). However, it is not guaranteed that the operation will succeed. If the modification operation fails it falls back to File.setLastModified(long) and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if source or destination is invalid.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      See Also:

    • copyFileToDirectory

      public static void copyFileToDirectory(File sourceFile, File destinationDir, boolean preserveFileDate) throws 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 falls back to File.setLastModified(long) and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      IOException - if the output file length is not the same as the input file length after the copy completes.
      Since:
      1.3
      See Also:

    • copyInputStreamToFile

      public static void copyInputStreamToFile(InputStream source, File destination) throws IOException
      Copies bytes from an InputStream source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.

      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:
      IOException - if destination is a directory
      IOException - if destination cannot be written
      IOException - if destination needs creating but can't be
      IOException - if an IO error occurs during copying
      Since:
      2.0

    • copyToDirectory

      public static void copyToDirectory(File sourceFile, File destinationDir) throws IOException
      Copies a file or directory to within another directory preserving the file dates.

      This method copies the source file or directory, along with 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 does 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 falls back to File.setLastModified(long) and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if the source or destination is invalid.
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      2.6
      See Also:

    • copyToDirectory

      public static void copyToDirectory(Iterable<File> sourceIterable, File destinationDir) throws 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: 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 falls back to File.setLastModified(long) and if that fails, the method 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:
      NullPointerException - if any of the given Files are null.
      IOException - if source or destination is invalid.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      2.6
      See Also:

    • copyToFile

      public static void copyToFile(InputStream inputStream, File file) throws IOException
      Copies bytes from an InputStream source to a File destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists. 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:
      NullPointerException - if the InputStream is null.
      NullPointerException - if the File is null.
      IllegalArgumentException - if the file object is a directory.
      IllegalArgumentException - if the file is not writable.
      IOException - if the directories could not be created.
      IOException - if an IO error occurs during copying.
      Since:
      2.5

    • copyURLToFile

      public static void copyURLToFile(URL source, File destination) throws IOException
      Copies bytes from the URL source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.

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

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

    • copyURLToFile

      public static void copyURLToFile(URL source, File destination, int connectionTimeoutMillis, int readTimeoutMillis) throws IOException
      Copies bytes from the URL source to a file destination. The directories up to destination will be created if they don't already exist. destination will be overwritten if it already exists.
      Parameters:
      source - the URL to copy bytes from, must not be null
      destination - the non-directory File to write bytes to (possibly overwriting), must not be null
      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:
      IOException - if source URL cannot be opened
      IOException - if destination is a directory
      IOException - if destination cannot be written
      IOException - if destination needs creating but can't be
      IOException - if an IO error occurs during copying
      Since:
      2.0

    • createParentDirectories

      public static File createParentDirectories(File file) throws IOException
      Creates all parent directories for a File object, including any necessary but non-existent 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:
      IOException - if the directory was not created along with all its parent directories.
      SecurityException - See File.mkdirs().
      Since:
      2.9.0

    • current

      public static File current()
      Gets the current directory.
      Returns:
      the current directory.
      Since:
      2.12.0

    • delete

      public static File delete(File file) throws 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:
      NullPointerException - if the parameter is null
      IOException - if the file cannot be deleted.
      Since:
      2.9.0
      See Also:

    • deleteDirectory

      public static void deleteDirectory(File directory) throws IOException
      Deletes a directory recursively.
      Parameters:
      directory - directory to delete
      Throws:
      IOException - in case deletion is unsuccessful
      NullPointerException - if the parameter is null
      IllegalArgumentException - if directory is not a directory

    • deleteQuietly

      public static boolean deleteQuietly(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(File directory, File child) throws IOException
      Determines whether the parent directory contains the child element (a file or directory).

      Files are normalized before comparison.

      Edge cases:
      • A directory must not be null: if null, throw NullPointerException
      • A directory must be a directory: if not a directory, throw IllegalArgumentException
      • A directory does not contain itself: return false
      • A null child file is not contained in any parent: return false
      Parameters:
      directory - the file to consider as the parent.
      child - the file to consider as the child.
      Returns:
      true is the candidate leaf is under by the specified composite. False otherwise.
      Throws:
      IOException - if an IO error occurs while checking the files.
      NullPointerException - if the parent is null.
      IllegalArgumentException - if the parent is not a directory.
      Since:
      2.2
      See Also:

    • forceDelete

      public static void forceDelete(File file) throws 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:
      NullPointerException - if the file is null.
      FileNotFoundException - if the file was not found.
      IOException - in case deletion is unsuccessful.

    • forceDeleteOnExit

      public static void forceDeleteOnExit(File file) throws IOException
      Schedules a file to be deleted when JVM exits. If file is directory delete it and all subdirectories.
      Parameters:
      file - file or directory to delete, must not be null.
      Throws:
      NullPointerException - if the file is null.
      IOException - in case deletion is unsuccessful.

    • forceMkdir

      public static void forceMkdir(File directory) throws IOException
      Creates all directories for a File object, including any necessary but non-existent 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:
      IOException - if the directory was not created along with all its parent directories.
      IOException - if the given file object is not a directory.
      SecurityException - See File.mkdirs().
      See Also:

    • forceMkdirParent

      public static void forceMkdirParent(File file) throws IOException
      Creates all directories for a File object, including any necessary but non-existent parent directories. If the parent directory already exists or is null, nothing happens.

      Calls File.mkdirs() for the parent of file.

      Parameters:
      file - file with parents to create, must not be null.
      Throws:
      NullPointerException - if the file is null.
      IOException - if the directory was not created along with all its parent directories.
      SecurityException - See File.mkdirs().
      Since:
      2.5
      See Also:

    • getFile

      public static File getFile(File directory, 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 File getFile(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 File getTempDirectory()
      Returns a File representing the system temporary directory.
      Returns:
      the system temporary directory as a File
      Since:
      2.0

    • getTempDirectoryPath

      public static String getTempDirectoryPath()
      Returns the path to the system temporary directory. WARNING: this method relies on the Java system property 'java.io.tmpdir' which may or may not have a trailing file separator. This can affect code that uses String processing to manipulate pathnames rather than the standard libary methods in classes such as File
      Returns:
      the path to the system temporary directory as a String
      Since:
      2.0

    • getUserDirectory

      public static File getUserDirectory()
      Returns a File representing the user's home directory.
      Returns:
      the user's home directory.
      Since:
      2.0

    • getUserDirectoryPath

      public static String getUserDirectoryPath()
      Returns the path to the user's home directory.
      Returns:
      the path to the user's home directory.
      Since:
      2.0

    • isDirectory

      public static boolean isDirectory(File 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:
      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(File directory) throws IOException
      Tests whether the directory is empty.
      Parameters:
      directory - the directory to query.
      Returns:
      whether the directory is empty.
      Throws:
      IOException - if an I/O error occurs.
      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(File file, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file or local date is null.
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, ChronoLocalDate chronoLocalDate, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file, local date or zone ID is null.
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, ChronoLocalDate chronoLocalDate, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file, local date or zone ID is null
      Since:
      2.12.0

    • isFileNewer

      public static boolean isFileNewer(File file, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file or local date time is null.
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, ChronoLocalDateTime<?> chronoLocalDateTime, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file, local date time or zone ID is null.
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, 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:
      NullPointerException - if the file or zoned date time is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, Date date)
      Tests if the specified File is newer than the specified Date.
      Parameters:
      file - the File of which the modification date must be compared.
      date - the date reference.
      Returns:
      true if the File exists and has been modified after the given Date.
      Throws:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file or date is null.

    • isFileNewer

      public static boolean isFileNewer(File file, File reference)
      Tests if the specified File is newer than the reference File.
      Parameters:
      file - the File of which the modification date must be compared.
      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:
      NullPointerException - if the file or reference file is null.
      UncheckedIOException - if the reference file doesn't exist.

    • isFileNewer

      public static boolean isFileNewer(File file, FileTime fileTime) throws 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:
      IOException - if an I/O error occurs.
      NullPointerException - if the file or local date is null.
      Since:
      2.12.0

    • isFileNewer

      public static boolean isFileNewer(File file, 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:
      NullPointerException - if the file or instant is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0

    • isFileNewer

      public static boolean isFileNewer(File file, long timeMillis)
      Tests if the specified File is newer than the specified time reference.
      Parameters:
      file - the File of which the modification date must be compared.
      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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file is null.

    • isFileNewer

      public static boolean isFileNewer(File file, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file or zoned date time is null
      Since:
      2.12.0

    • isFileOlder

      public static boolean isFileOlder(File file, 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:
      NullPointerException - if the file or local date is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0
      See Also:

    • isFileOlder

      public static boolean isFileOlder(File file, ChronoLocalDate chronoLocalDate, 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:
      UncheckedIOException - if an I/O error occurs
      NullPointerException - if the file, local date or local time is null.
      Since:
      2.8.0
      See Also:

    • isFileOlder

      public static boolean isFileOlder(File file, ChronoLocalDate chronoLocalDate, 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:
      NullPointerException - if the file, local date or zone ID is null
      UncheckedIOException - if an I/O error occurs
      Since:
      2.12.0

    • isFileOlder

      public static boolean isFileOlder(File file, 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:
      NullPointerException - if the file or local date time is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0
      See Also:

    • isFileOlder

      public static boolean isFileOlder(File file, ChronoLocalDateTime<?> chronoLocalDateTime, 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:
      NullPointerException - if the file, local date time or zone ID is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0

    • isFileOlder

      public static boolean isFileOlder(File file, 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:
      NullPointerException - if the file or zoned date time is null.
      UncheckedIOException - if an I/O error occurs
      Since:
      2.8.0

    • isFileOlder

      public static boolean isFileOlder(File file, Date date)
      Tests if the specified File is older than the specified Date.
      Parameters:
      file - the File of which the modification date must be compared.
      date - the date reference.
      Returns:
      true if the File exists and has been modified before the given Date.
      Throws:
      NullPointerException - if the file or date is null.
      UncheckedIOException - if an I/O error occurs

    • isFileOlder

      public static boolean isFileOlder(File file, File reference) throws FileNotFoundException
      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:
      NullPointerException - if the file or reference file is null.
      FileNotFoundException - if the reference file doesn't exist.
      UncheckedIOException - if an I/O error occurs

    • isFileOlder

      public static boolean isFileOlder(File file, FileTime fileTime) throws 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:
      IOException - if an I/O error occurs.
      NullPointerException - if the file or local date is null.
      Since:
      2.12.0

    • isFileOlder

      public static boolean isFileOlder(File file, 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:
      NullPointerException - if the file or instant is null.
      Since:
      2.8.0

    • isFileOlder

      public static boolean isFileOlder(File file, long timeMillis)
      Tests if the specified File is older than the specified time reference.
      Parameters:
      file - the File of which the modification date must be compared.
      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:
      NullPointerException - if the file is null.
      UncheckedIOException - if an I/O error occurs

    • isFileOlder

      public static boolean isFileOlder(File file, 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:
      NullPointerException - if the file or zoned date time is null
      Since:
      2.12.0

    • isRegularFile

      public static boolean isRegularFile(File 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:
      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(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:

    • iterateFiles

      public static Iterator<File> iterateFiles(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 File for the matching files
      Since:
      1.2
      See Also:

    • iterateFiles

      public static Iterator<File> iterateFiles(File directory, 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, for example, {"java","xml"}. If this parameter is null, all files are returned.
      recursive - if true all subdirectories are searched as well
      Returns:
      an iterator of File with the matching files
      Since:
      1.2

    • iterateFilesAndDirs

      public static Iterator<File> iterateFilesAndDirs(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 File for the matching files
      Since:
      2.2
      See Also:

    • lastModified

      public static long lastModified(File file) throws 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:
      IOException - if an I/O error occurs.
      Since:
      2.9.0

    • lastModifiedFileTime

      public static FileTime lastModifiedFileTime(File file) throws 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:
      IOException - if an I/O error occurs.
      Since:
      2.12.0

    • lastModifiedUnchecked

      public static long lastModifiedUnchecked(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:
      UncheckedIOException - if an I/O error occurs.
      Since:
      2.9.0

    • lineIterator

      public static LineIterator lineIterator(File file) throws IOException
      Returns an Iterator for the lines in a File using the default encoding for the VM.
      Parameters:
      file - the file to open for input, must not be null
      Returns:
      an Iterator of the lines in the file, never null
      Throws:
      NullPointerException - if file is null.
      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.
      IOException - if an I/O error occurs.
      Since:
      1.3
      See Also:

    • lineIterator

      public static LineIterator lineIterator(File file, String charsetName) throws IOException
      Returns an Iterator for the lines in a File.

      This method opens an InputStream for the file. When you have finished with the iterator you should close the stream to free internal resources. This can be done by 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:
      NullPointerException - if file is null.
      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.
      IOException - if an I/O error occurs.
      Since:
      1.2

    • listFiles

      public static Collection<File> listFiles(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)
      Finds files within a given directory (and optionally its subdirectories). All files found are filtered by an IOFileFilter.

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

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

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

      Parameters:
      directory - the directory to search in
      fileFilter - filter to apply when finding files. 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 File with the matching files
      See Also:

    • listFiles

      public static Collection<File> listFiles(File directory, String[] extensions, boolean recursive)
      Lists 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, for example, {"java","xml"}. If this parameter is null, all files are returned.
      recursive - if true all subdirectories are searched as well
      Returns:
      a collection of File with the matching files

    • listFilesAndDirs

      public static Collection<File> listFilesAndDirs(File directory, IOFileFilter fileFilter, IOFileFilter dirFilter)
      Finds files within a given directory (and optionally its subdirectories). All files found are filtered by an IOFileFilter.

      The resulting collection includes the 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 File with the matching files
      Since:
      2.2
      See Also:

    • moveDirectory

      public static void moveDirectory(File srcDir, File destDir) throws IOException
      Moves a directory.

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

      Parameters:
      srcDir - the directory to be moved.
      destDir - the destination directory.
      Throws:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if srcDir exists but is not a directory
      FileNotFoundException - if the source does not exist.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      1.4

    • moveDirectoryToDirectory

      public static void moveDirectoryToDirectory(File source, File destDir, boolean createDestDir) throws IOException
      Moves a directory to another directory.

      If createDestDir is true, creates all destination parent directories, including any necessary but non-existent parent directories.

      Parameters:
      source - the directory to be moved.
      destDir - the destination file.
      createDestDir - If true create the destination directory, otherwise if false throw an IOException.
      Throws:
      NullPointerException - if any of the given Files are null.
      IllegalArgumentException - if the source or destination is invalid.
      FileNotFoundException - if the source does not exist.
      IOException - if the directory was not created along with all its parent directories, if enabled.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      SecurityException - See File.mkdirs().
      Since:
      1.4

    • moveFile

      public static void moveFile(File srcFile, File destFile) throws 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:
      NullPointerException - if any of the given Files are null.
      FileExistsException - if the destination file exists.
      FileNotFoundException - if the source file does not exist.
      IllegalArgumentException - if srcFile is a directory
      IOException - if an error occurs.
      Since:
      1.4

    • moveFile

      public static void moveFile(File srcFile, File destFile, CopyOption... copyOptions) throws IOException
      Moves a file.

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

      Parameters:
      srcFile - the file to be moved.
      destFile - the destination file.
      copyOptions - Copy options.
      Throws:
      NullPointerException - if any of the given Files are null.
      FileExistsException - if the destination file exists.
      FileNotFoundException - if the source file does not exist.
      IllegalArgumentException - if srcFile is a directory
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      2.9.0

    • moveFileToDirectory

      public static void moveFileToDirectory(File srcFile, File destDir, boolean createDestDir) throws IOException
      Moves a file into a directory.

      If createDestDir is true, creates all destination parent directories, including any necessary but non-existent parent directories.

      Parameters:
      srcFile - the file to be moved.
      destDir - the directory to move the file into
      createDestDir - if true create the destination directory. If false throw an IOException if the destination directory does not already exist.
      Throws:
      NullPointerException - if any of the given Files are null.
      FileExistsException - if the destination file exists.
      FileNotFoundException - if the source file does not exist.
      IOException - if source or destination is invalid.
      IOException - if the directory was not created along with all its parent directories, if enabled.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      SecurityException - See File.mkdirs().
      IllegalArgumentException - if destDir exists but is not a directory
      Since:
      1.4

    • moveToDirectory

      public static void moveToDirectory(File src, File destDir, boolean createDestDir) throws IOException
      Moves a file or directory into a destination directory.

      If createDestDir is true, creates all destination parent directories, including any necessary but non-existent 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. If false throw an IOException if the destination directory does not already exist.
      Throws:
      NullPointerException - if any of the given Files are null.
      FileExistsException - if the directory or file exists in the destination directory.
      FileNotFoundException - if the source file does not exist.
      IOException - if source or destination is invalid.
      IOException - if an error occurs or setting the last-modified time didn't succeed.
      Since:
      1.4

    • newOutputStream

      public static OutputStream newOutputStream(File file, boolean append) throws 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:
      IOException - if an I/O error occurs.
      Since:
      2.12.0
      See Also:

    • openInputStream

      public static FileInputStream openInputStream(File file) throws IOException
      Opens a FileInputStream for the specified file, providing better error messages than simply calling new FileInputStream(file).

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

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

      Parameters:
      file - the file to open for input, must not be null
      Returns:
      a new FileInputStream for the specified file
      Throws:
      NullPointerException - if file is null.
      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.
      IOException - See FileNotFoundException above, FileNotFoundException is a subclass of IOException.
      Since:
      1.3

    • openOutputStream

      public static FileOutputStream openOutputStream(File file) throws IOException
      Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

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

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

      Parameters:
      file - the file to open for output, must not be null
      Returns:
      a new FileOutputStream for the specified file
      Throws:
      NullPointerException - if the file object is null.
      IllegalArgumentException - if the file object is a directory
      IllegalArgumentException - if the file is not writable.
      IOException - if the directories could not be created.
      Since:
      1.3

    • openOutputStream

      public static FileOutputStream openOutputStream(File file, boolean append) throws IOException
      Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

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

      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:
      NullPointerException - if the file object is null.
      IllegalArgumentException - if the file object is a directory
      IOException - if the directories could not be created, or the file is not writable
      Since:
      2.1

    • readFileToByteArray

      public static byte[] readFileToByteArray(File file) throws IOException
      Reads the contents of a file into a byte array. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      Returns:
      the file contents, never null
      Throws:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      Since:
      1.1

    • readFileToString

      @Deprecated public static String readFileToString(File file) throws IOException
      Deprecated.
      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:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      Since:
      1.3.1

    • readFileToString

      public static String readFileToString(File file, Charset charsetName) throws IOException
      Reads the contents of a file into a String. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the file contents, never null
      Throws:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      Since:
      2.3

    • readFileToString

      public static String readFileToString(File file, String charsetName) throws IOException
      Reads the contents of a file into a String. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      charsetName - the name of the requested charset, null means platform default
      Returns:
      the file contents, never null
      Throws:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      UnsupportedCharsetException - if the named charset is unavailable.
      Since:
      2.3

    • readLines

      @Deprecated public static List<String> readLines(File file) throws IOException
      Deprecated.
      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:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      Since:
      1.3

    • readLines

      public static List<String> readLines(File file, Charset charset) throws IOException
      Reads the contents of a file line by line to a List of Strings. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      charset - the charset to use, null means platform default
      Returns:
      the list of Strings representing each line in the file, never null
      Throws:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      Since:
      2.3

    • readLines

      public static List<String> readLines(File file, String charsetName) throws IOException
      Reads the contents of a file line by line to a List of Strings. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      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:
      NullPointerException - if file is null.
      IOException - if an I/O error occurs, including when the file does not exist, is a directory rather than a regular file, or for some other reason why the file cannot be opened for reading.
      UnsupportedCharsetException - if the named charset is unavailable.
      Since:
      1.1

    • sizeOf

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

      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:
      NullPointerException - if the file is null.
      IllegalArgumentException - if the file does not exist.
      UncheckedIOException - if an IO error occurs.
      Since:
      2.0

    • sizeOfAsBigInteger

      public static BigInteger sizeOfAsBigInteger(File file)
      Returns the size of the specified file or directory. If the provided File is a regular file, then the file's length is returned. If the argument is a directory, then the size of the directory is calculated recursively. If a directory or subdirectory is security restricted, its size will not be included.
      Parameters:
      file - the regular file or directory to return the size of (must not be null).
      Returns:
      the length of the file, or recursive size of the directory, provided (in bytes).
      Throws:
      NullPointerException - if the file is null.
      IllegalArgumentException - if the file does not exist.
      UncheckedIOException - if an IO error occurs.
      Since:
      2.4

    • sizeOfDirectory

      public static long sizeOfDirectory(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:
      IllegalArgumentException - if the given File exists but is not a directory
      NullPointerException - if the directory is null.
      UncheckedIOException - if an IO error occurs.

    • sizeOfDirectoryAsBigInteger

      public static BigInteger sizeOfDirectoryAsBigInteger(File directory)
      Counts the size of a directory recursively (sum of the length of all files).
      Parameters:
      directory - directory to inspect, must not be null.
      Returns:
      size of directory in bytes, 0 if directory is security restricted.
      Throws:
      IllegalArgumentException - if the given File exists but is not a directory
      NullPointerException - if the directory is null.
      UncheckedIOException - if an IO error occurs.
      Since:
      2.4

    • streamFiles

      public static Stream<File> streamFiles(File directory, boolean recursive, String... extensions) throws IOException
      Streams over the files in a given directory (and optionally its subdirectories) which match an array of extensions.

      The returned Stream may wrap one or more DirectoryStreams. When you require timely disposal of file system resources, use a try-with-resources block to ensure invocation of the stream's BaseStream.close() method after the stream operations are completed. Calling a closed stream causes a IllegalStateException.

      Parameters:
      directory - the directory to search in
      recursive - if true all subdirectories are searched as well
      extensions - an array of extensions, for example, {"java","xml"}. If this parameter is null, all files are returned.
      Returns:
      a Stream of File for matching files.
      Throws:
      IOException - if an I/O error is thrown when accessing the starting file.
      Since:
      2.9.0

    • toFile

      public static File toFile(URL url)
      Converts from a URL to a File.

      Syntax such as file:///my%20docs/file.txt will be correctly decoded to /my docs/file.txt. UTF-8 is used to decode percent-encoded octets to characters. Additionally, malformed percent-encoded octets are handled leniently by passing them through literally.

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

    • toFiles

      public static File[] toFiles(URL... urls)
      Converts each of an array of URL to a File.

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

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

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

    • touch

      public static void touch(File file) throws 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. This method throws an IOException if the last modified date of the file cannot be set. It creates parent directories if they do not exist.
      Parameters:
      file - the File to touch.
      Throws:
      NullPointerException - if the parameter is null.
      IOException - if setting the last-modified time failed or an I/O problem occurs.

    • toURLs

      public static URL[] toURLs(File... files) throws IOException
      Converts each element of an array of File to a URL.

      Returns an array of the same size as the input.

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

    • waitFor

      public static boolean waitFor(File file, int seconds)
      Waits for the file system to detect a file's presence, 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:
      NullPointerException - if the file is null

    • write

      @Deprecated public static void write(File file, CharSequence data) throws IOException
      Deprecated.
      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:
      IOException - in case of an I/O error
      Since:
      2.0

    • write

      @Deprecated public static void write(File file, CharSequence data, boolean append) throws IOException
      Deprecated.
      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:
      IOException - in case of an I/O error
      Since:
      2.1

    • write

      public static void write(File file, CharSequence data, Charset charset) throws IOException
      Writes a CharSequence to a file creating the file if it does not exist.
      Parameters:
      file - the file to write
      data - the content to write to the file
      charset - the name of the requested charset, null means platform default
      Throws:
      IOException - in case of an I/O error
      Since:
      2.3

    • write

      public static void write(File file, CharSequence data, Charset charset, boolean append) throws IOException
      Writes a CharSequence to a file creating the file if it does not exist.
      Parameters:
      file - the file to write
      data - the content to write to the file
      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:
      IOException - in case of an I/O error
      Since:
      2.3

    • write

      public static void write(File file, CharSequence data, String charsetName) throws IOException
      Writes a CharSequence to a file creating the file if it does not exist.
      Parameters:
      file - the file to write
      data - the content to write to the file
      charsetName - the name of the requested charset, null means platform default
      Throws:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      2.0

    • write

      public static void write(File file, CharSequence data, String charsetName, boolean append) throws IOException
      Writes a CharSequence to a file creating the file if it does not exist.
      Parameters:
      file - the file to write
      data - the content to write to the file
      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:
      IOException - in case of an I/O error
      UnsupportedCharsetException - if the encoding is not supported by the VM
      Since:
      2.1

    • writeByteArrayToFile

      public static void writeByteArrayToFile(File file, byte[] data) throws IOException
      Writes a byte array to a file creating the file if it does not exist. The parent directories of the file will be created if they do not exist.
      Parameters:
      file - the file to write to
      data - the content to write to the file
      Throws:
      IOException - in case of an I/O error
      Since:
      1.1

    • writeByteArrayToFile

      public static void writeByteArrayToFile(File file, byte[] data, boolean append) throws IOException
      Writes a byte array to a file creating the file if it does not exist.
      Parameters:
      file - the file to write to
      data - the content to write to the file
      append - if true, then bytes will be added to the end of the file rather than overwriting
      Throws:
      IOException - in case of an I/O error
      Since:
      2.1

    • writeByteArrayToFile

      public static void writeByteArrayToFile(File file, byte[] data, int off, int len) throws 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:
      IOException - in case of an I/O error
      Since:
      2.5

    • writeByteArrayToFile

      public static void writeByteArrayToFile(File file, byte[] data, int off, int len, boolean append) throws 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:
      IOException - in case of an I/O error
      Since:
      2.5

    • writeLines

      public static void writeLines(File file, Collection<?> lines) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the default line ending will be used.
      Parameters:
      file - the file to write to
      lines - the lines to write, null entries produce blank lines
      Throws:
      IOException - in case of an I/O error
      Since:
      1.3

    • writeLines

      public static void writeLines(File file, Collection<?> lines, boolean append) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the default line ending will be used.
      Parameters:
      file - the file to write to
      lines - the lines to write, null entries produce blank lines
      append - if true, then the lines will be added to the end of the file rather than overwriting
      Throws:
      IOException - in case of an I/O error
      Since:
      2.1

    • writeLines

      public static void writeLines(File file, Collection<?> lines, String lineEnding) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the specified line ending will be used.
      Parameters:
      file - the file to write to
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      Throws:
      IOException - in case of an I/O error
      Since:
      1.3

    • writeLines

      public static void writeLines(File file, Collection<?> lines, String lineEnding, boolean append) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The default VM encoding and the specified line ending will be used.
      Parameters:
      file - the file to write to
      lines - the lines to write, null entries produce blank lines
      lineEnding - the line separator to use, null is system default
      append - if true, then the lines will be added to the end of the file rather than overwriting
      Throws:
      IOException - in case of an I/O error
      Since:
      2.1

    • writeLines

      public static void writeLines(File file, String charsetName, Collection<?> lines) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the default line ending will be used. 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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      1.1

    • writeLines

      public static void writeLines(File file, String charsetName, Collection<?> lines, boolean append) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line, optionally appending. The specified character encoding and the default line ending will be used.
      Parameters:
      file - the file to write to
      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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      2.1

    • writeLines

      public static void writeLines(File file, String charsetName, Collection<?> lines, String lineEnding) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the line ending will be used. 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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      1.1

    • writeLines

      public static void writeLines(File file, String charsetName, Collection<?> lines, String lineEnding, boolean append) throws IOException
      Writes the toString() value of each item in a collection to the specified File line by line. The specified character encoding and the line ending will be used.
      Parameters:
      file - the file to write to
      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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      2.1

    • writeStringToFile

      @Deprecated public static void writeStringToFile(File file, String data) throws IOException
      Deprecated.
      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:
      IOException - in case of an I/O error

    • writeStringToFile

      @Deprecated public static void writeStringToFile(File file, String data, boolean append) throws IOException
      Deprecated.
      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:
      IOException - in case of an I/O error
      Since:
      2.1

    • writeStringToFile

      public static void writeStringToFile(File file, String data, Charset charset) throws IOException
      Writes a String to a file creating the file if it does not exist. 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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM
      Since:
      2.4

    • writeStringToFile

      public static void writeStringToFile(File file, String data, Charset charset, boolean append) throws IOException
      Writes a String to a file, creating the file if it does not exist. The parent directories of the file are 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
      append - if true, then the String will be added to the end of the file rather than overwriting
      Throws:
      IOException - in case of an I/O error
      Since:
      2.3

    • writeStringToFile

      public static void writeStringToFile(File file, String data, String charsetName) throws IOException
      Writes a String to a file, creating the file if it does not exist. The parent directories of the file are 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:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM

    • writeStringToFile

      public static void writeStringToFile(File file, String data, String charsetName, boolean append) throws IOException
      Writes a String to a file, creating the file if it does not exist. The parent directories of the file are 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
      append - if true, then the String will be added to the end of the file rather than overwriting
      Throws:
      IOException - in case of an I/O error
      UnsupportedCharsetException - if the encoding is not supported by the VM
      Since:
      2.1