Class FileUtilsV2_2

  • Direct Known Subclasses:
    FileUtils

    public class FileUtilsV2_2
    extends java.lang.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 Summary

      Fields 
      Modifier and Type Field Description
      static java.io.File[] EMPTY_FILE_ARRAY
      An empty array of type File.
      private static long FILE_COPY_BUFFER_SIZE
      The file copy buffer size (30 MB)
      static long ONE_EB
      The number of bytes in an exabyte.
      static long ONE_GB
      The number of bytes in a gigabyte.
      static long ONE_KB
      The number of bytes in a kilobyte.
      static long ONE_MB
      The number of bytes in a megabyte.
      static long ONE_PB
      The number of bytes in a petabyte.
      static long ONE_TB
      The number of bytes in a terabyte.
      static java.math.BigInteger ONE_YB
      The number of bytes in a yottabyte.
      static java.math.BigInteger ONE_ZB
      The number of bytes in a zettabyte.
    • Constructor Summary

      Constructors 
      Constructor Description
      FileUtilsV2_2()
      Instances should NOT be constructed in standard programming.
    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static void cleanDirectory​(java.io.File directory)
      Cleans a directory without deleting it.
      private static void cleanDirectoryOnExit​(java.io.File directory)
      Cleans a directory without deleting it.
      static boolean contentEquals​(java.io.File file1, java.io.File file2)
      Compares the contents of two files to determine if they are equal or not.
      static void copyDirectory​(java.io.File srcDir, java.io.File destDir)
      Copies a whole directory to a new location preserving the file dates.
      static void copyDirectory​(java.io.File srcDir, java.io.File destDir, boolean preserveFileDate)
      Copies a whole directory to a new location.
      static void copyDirectory​(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter, boolean preserveFileDate)
      Copies a filtered directory to a new location.
      static void copyFile​(java.io.File srcFile, java.io.File destFile)
      Copies a file to a new location preserving the file date.
      static void copyFile​(java.io.File srcFile, java.io.File destFile, boolean preserveFileDate)
      Copies a file to a new location.
      static void copyFileToDirectory​(java.io.File srcFile, java.io.File destDir)
      Copies a file to a directory preserving the file date.
      static void copyFileToDirectory​(java.io.File srcFile, java.io.File destDir, boolean preserveFileDate)
      Copies a file to a directory optionally preserving the file date.
      static void deleteDirectory​(java.io.File directory)
      Deletes a directory recursively.
      private static void deleteDirectoryOnExit​(java.io.File directory)
      Schedules a directory recursively for deletion on JVM exit.
      static boolean deleteQuietly​(java.io.File file)
      Deletes a file, never throwing an exception.
      private static void doCopyDirectory​(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter, boolean preserveFileDate, java.util.List<java.lang.String> exclusionList)
      Internal copy directory method.
      private static void doCopyFile​(java.io.File srcFile, java.io.File destFile, boolean preserveFileDate)
      Internal copy file method.
      static void forceDelete​(java.io.File file)
      Deletes a file.
      static void forceDeleteOnExit​(java.io.File file)
      Schedules a file to be deleted when JVM exits.
      static void forceMkdir​(java.io.File directory)
      Makes a directory, including any necessary but nonexistent parent directories.
      static boolean isSymlink​(java.io.File file)
      Determines whether the specified file is a Symbolic Link rather than an actual file.
      static void moveDirectory​(java.io.File srcDir, java.io.File destDir)
      Moves a directory.
      static void moveFile​(java.io.File srcFile, java.io.File destFile)
      Moves a file.
      static java.io.FileInputStream openInputStream​(java.io.File file)
      Opens a FileInputStream for the specified file, providing better error messages than simply calling new FileInputStream(file).
      static java.io.FileOutputStream openOutputStream​(java.io.File file)
      Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.
      static java.io.FileOutputStream openOutputStream​(java.io.File file, boolean append)
      Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.
      static java.lang.String readFileToString​(java.io.File file)
      Reads the contents of a file into a String using the default encoding for the VM.
      static java.lang.String readFileToString​(java.io.File file, java.lang.String encoding)
      Reads the contents of a file into a String.
      static long sizeOf​(java.io.File file)
      Returns the size of the specified file or directory.
      static long sizeOfDirectory​(java.io.File directory)
      Counts the size of a directory recursively (sum of the length of all files).
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • ONE_KB

        public static final long ONE_KB
        The number of bytes in a kilobyte.
        See Also:
        Constant Field Values
      • ONE_MB

        public static final long ONE_MB
        The number of bytes in a megabyte.
        See Also:
        Constant Field Values
      • FILE_COPY_BUFFER_SIZE

        private static final long FILE_COPY_BUFFER_SIZE
        The file copy buffer size (30 MB)
        See Also:
        Constant Field Values
      • ONE_GB

        public static final long ONE_GB
        The number of bytes in a gigabyte.
        See Also:
        Constant Field Values
      • ONE_TB

        public static final long ONE_TB
        The number of bytes in a terabyte.
        See Also:
        Constant Field Values
      • ONE_PB

        public static final long ONE_PB
        The number of bytes in a petabyte.
        See Also:
        Constant Field Values
      • ONE_EB

        public static final long ONE_EB
        The number of bytes in an exabyte.
        See Also:
        Constant Field Values
      • ONE_ZB

        public static final java.math.BigInteger ONE_ZB
        The number of bytes in a zettabyte.
      • ONE_YB

        public static final java.math.BigInteger ONE_YB
        The number of bytes in a yottabyte.
      • EMPTY_FILE_ARRAY

        public static final java.io.File[] EMPTY_FILE_ARRAY
        An empty array of type File.
    • Constructor Detail

      • FileUtilsV2_2

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

      • openInputStream

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        Code origin: Avalon

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

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

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

        Note: This method tries to preserve the file's last modified date/times using 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        See Also:
        copyFile(File, File, boolean)
      • copyFileToDirectory

        public static void copyFileToDirectory​(java.io.File srcFile,
                                               java.io.File destDir,
                                               boolean preserveFileDate)
                                        throws java.io.IOException
        Copies a file to a directory optionally preserving the file date.

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

        Note: Setting preserveFileDate to true tries to preserve the file's last modified date/times using 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        Since:
        1.3
        See Also:
        copyFile(File, File, boolean)
      • copyFile

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

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

        Note: This method tries to preserve the file's last modified date/times using 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        See Also:
        copyFileToDirectory(File, File)
      • copyFile

        public static void copyFile​(java.io.File srcFile,
                                    java.io.File destFile,
                                    boolean preserveFileDate)
                             throws java.io.IOException
        Copies a file to a new location.

        This method copies the contents of the specified source file to the specified destination file. The directory holding the destination file is created if it does not exist. If the destination file exists, 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        See Also:
        copyFileToDirectory(File, File, boolean)
      • doCopyFile

        private static void doCopyFile​(java.io.File srcFile,
                                       java.io.File destFile,
                                       boolean preserveFileDate)
                                throws java.io.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:
        java.io.IOException - if an error occurs
      • copyDirectory

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

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

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

        Note: 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        Since:
        1.1
      • copyDirectory

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

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

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

        Note: Setting preserveFileDate to true tries to preserve the files' last modified date/times using File.setLastModified(long), however it is not guaranteed that those operations will succeed. If the modification operation fails, 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        Since:
        1.1
      • copyDirectory

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

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

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

        Note: Setting preserveFileDate to true tries to preserve the 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:
        java.lang.NullPointerException - if source or destination is null
        java.io.IOException - if source or destination is invalid
        java.io.IOException - if an IO error occurs during copying
        Since:
        1.4
      • doCopyDirectory

        private static void doCopyDirectory​(java.io.File srcDir,
                                            java.io.File destDir,
                                            java.io.FileFilter filter,
                                            boolean preserveFileDate,
                                            java.util.List<java.lang.String> exclusionList)
                                     throws java.io.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:
        java.io.IOException - if an error occurs
        Since:
        1.1
      • deleteDirectory

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

        public static boolean deleteQuietly​(java.io.File file)
        Deletes a file, never throwing an exception. If file is a directory, delete it and all 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​(java.io.File directory)
                                   throws java.io.IOException
        Cleans a directory without deleting it.
        Parameters:
        directory - directory to clean
        Throws:
        java.io.IOException - in case cleaning is unsuccessful
      • readFileToString

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

        public static java.lang.String readFileToString​(java.io.File file)
                                                 throws java.io.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:
        java.io.IOException - in case of an I/O error
        Since:
        1.3.1
      • forceDelete

        public static void forceDelete​(java.io.File file)
                                throws java.io.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:
        java.lang.NullPointerException - if the directory is null
        java.io.FileNotFoundException - if the file was not found
        java.io.IOException - in case deletion is unsuccessful
      • forceDeleteOnExit

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

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

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

        public static void forceMkdir​(java.io.File directory)
                               throws java.io.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:
        java.lang.NullPointerException - if the directory is null
        java.io.IOException - if the directory cannot be created or the file already exists but is not a directory
      • sizeOf

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

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

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

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

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

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

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

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

        public static boolean isSymlink​(java.io.File file)
                                 throws java.io.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:
        java.io.IOException - if an IO error occurs while checking the file
        Since:
        2.0