Class FileUtilsV2_2

java.lang.Object
org.zeroturnaround.zip.commons.FileUtilsV2_2
Direct Known Subclasses:
FileUtils
public class FileUtilsV2_2 extends Object
This is a class that has been made significantly smaller (deleted a bunch of methods) and originally is from the Apache Commons IO 2.2 package (the latest version that supports Java 1.5). All license and other documentation is intact. General file manipulation utilities.

Facilities are provided in the following areas:

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

Origin of code: Excalibur, Alexandria, Commons-Utils

Version:
$Id: FileUtils.java 1304052 2012-03-22 20:55:29Z ggregory $

  • Field Details

    • ONE_KB

      public static final long ONE_KB
      The number of bytes in a kilobyte.
      See Also:

    • ONE_MB

      public static final long ONE_MB
      The number of bytes in a megabyte.
      See Also:

    • FILE_COPY_BUFFER_SIZE

      private static final long FILE_COPY_BUFFER_SIZE
      The file copy buffer size (30 MB)
      See Also:

    • ONE_GB

      public static final long ONE_GB
      The number of bytes in a gigabyte.
      See Also:

    • ONE_TB

      public static final long ONE_TB
      The number of bytes in a terabyte.
      See Also:

    • ONE_PB

      public static final long ONE_PB
      The number of bytes in a petabyte.
      See Also:

    • ONE_EB

      public static final long ONE_EB
      The number of bytes in an exabyte.
      See Also:

    • ONE_ZB

      public static final BigInteger ONE_ZB
      The number of bytes in a zettabyte.

    • ONE_YB

      public static final BigInteger ONE_YB
      The number of bytes in a yottabyte.

    • EMPTY_FILE_ARRAY

      public static final File[] EMPTY_FILE_ARRAY
      An empty array of type File.

  • Constructor Details

    • FileUtilsV2_2

      public FileUtilsV2_2()
      Instances should NOT be constructed in standard programming.

  • Method Details

    • openInputStream

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

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

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

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

    • openOutputStream

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

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

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

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

    • openOutputStream

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

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

      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:
      IOException - if the file object is a directory
      IOException - if the file cannot be written to
      IOException - if a parent directory needs creating but that fails
      Since:
      2.1

    • contentEquals

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

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

      Code origin: Avalon

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

    • copyFileToDirectory

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

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

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

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

    • copyFileToDirectory

      public static void copyFileToDirectory(File srcFile, File destDir, 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 File.setLastModified(long), however it is not guaranteed that the operation will succeed. If the modification operation fails, no indication is provided.

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

    • copyFile

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

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

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

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

    • copyFile

      public static void copyFile(File srcFile, File destFile, boolean preserveFileDate) 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, then this method will overwrite it.

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

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

    • doCopyFile

      private static void doCopyFile(File srcFile, File destFile, boolean preserveFileDate) throws IOException
      Internal copy file method.
      Parameters:
      srcFile - the validated source file, must not be null
      destFile - the validated destination file, must not be null
      preserveFileDate - whether to preserve the file date
      Throws:
      IOException - if an error occurs

    • copyDirectory

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

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

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

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

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

    • copyDirectory

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

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

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

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

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

    • copyDirectory

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

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

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

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

      Example: Copy directories only

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

      Example: Copy directories and txt files

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

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

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

    • doCopyDirectory

      private static void doCopyDirectory(File srcDir, File destDir, FileFilter filter, boolean preserveFileDate, List<String> exclusionList) throws IOException
      Internal copy directory method.
      Parameters:
      srcDir - the validated source directory, must not be null
      destDir - the validated destination directory, must not be null
      filter - the filter to apply, null means copy all directories and files
      preserveFileDate - whether to preserve the file date
      exclusionList - List of files and directories to exclude from the copy, may be null
      Throws:
      IOException - if an error occurs
      Since:
      1.1

    • deleteDirectory

      public static void deleteDirectory(File directory) throws IOException
      Deletes a directory recursively.
      Parameters:
      directory - directory to delete
      Throws:
      IOException - in case deletion is unsuccessful

    • deleteQuietly

      public static boolean deleteQuietly(File file)
      Deletes a file, never throwing an exception. If file is a directory, delete it and all sub-directories.

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

      • A directory to be deleted does not have to be empty.
      • No exceptions are thrown when a file or directory cannot be deleted.
      Parameters:
      file - file or directory to delete, can be null
      Returns:
      true if the file or directory was deleted, otherwise false
      Since:
      1.4

    • cleanDirectory

      public static void cleanDirectory(File directory) throws IOException
      Cleans a directory without deleting it.
      Parameters:
      directory - directory to clean
      Throws:
      IOException - in case cleaning is unsuccessful

    • readFileToString

      public static String readFileToString(File file, String encoding) throws IOException
      Reads the contents of a file into a String. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      encoding - the encoding to use, null means platform default
      Returns:
      the file contents, never null
      Throws:
      IOException - in case of an I/O error
      UnsupportedEncodingException - if the encoding is not supported by the VM

    • readFileToString

      public static String readFileToString(File file) throws IOException
      Reads the contents of a file into a String using the default encoding for the VM. The file is always closed.
      Parameters:
      file - the file to read, must not be null
      Returns:
      the file contents, never null
      Throws:
      IOException - in case of an I/O error
      Since:
      1.3.1

    • forceDelete

      public static void forceDelete(File file) throws IOException
      Deletes a file. If file is a directory, delete it and all sub-directories.

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

      • A directory to be deleted does not have to be empty.
      • You get exceptions when a file or directory cannot be deleted. (java.io.File methods returns a boolean)
      Parameters:
      file - file or directory to delete, must not be null
      Throws:
      NullPointerException - if the directory is null
      FileNotFoundException - if the file was not found
      IOException - in case deletion is unsuccessful

    • forceDeleteOnExit

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

    • deleteDirectoryOnExit

      private static void deleteDirectoryOnExit(File directory) throws IOException
      Schedules a directory recursively for deletion on JVM exit.
      Parameters:
      directory - directory to delete, must not be null
      Throws:
      NullPointerException - if the directory is null
      IOException - in case deletion is unsuccessful

    • cleanDirectoryOnExit

      private static void cleanDirectoryOnExit(File directory) throws IOException
      Cleans a directory without deleting it.
      Parameters:
      directory - directory to clean, must not be null
      Throws:
      NullPointerException - if the directory is null
      IOException - in case cleaning is unsuccessful

    • forceMkdir

      public static void forceMkdir(File directory) throws IOException
      Makes a directory, including any necessary but nonexistent parent directories. If a file already exists with specified name but it is not a directory then an IOException is thrown. If the directory cannot be created (or does not already exist) then an IOException is thrown.
      Parameters:
      directory - directory to create, must not be null
      Throws:
      NullPointerException - if the directory is null
      IOException - if the directory cannot be created or the file already exists but is not a directory

    • sizeOf

      public static long sizeOf(File file)
      Returns the size of the specified file or directory. If the provided File is a regular file, then the file's length is returned. If the argument is a directory, then the size of the directory is calculated recursively. If a directory or subdirectory is security restricted, its size will not be included.
      Parameters:
      file - the regular file or directory to return the size of (must not be null).
      Returns:
      the length of the file, or recursive size of the directory, provided (in bytes).
      Throws:
      NullPointerException - if the file is null
      IllegalArgumentException - if the file does not exist.
      Since:
      2.0

    • sizeOfDirectory

      public static long sizeOfDirectory(File directory)
      Counts the size of a directory recursively (sum of the length of all files).
      Parameters:
      directory - directory to inspect, must not be null
      Returns:
      size of directory in bytes, 0 if directory is security restricted
      Throws:
      NullPointerException - if the directory is null

    • moveDirectory

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

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

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

    • moveFile

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

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

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

    • isSymlink

      public static boolean isSymlink(File file) throws IOException
      Determines whether the specified file is a Symbolic Link rather than an actual file.

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

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

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