Package com.therouter.plugin.utils

Class FileUtils

java.lang.Object

com.therouter.plugin.utils.FileUtils

public class FileUtils
extends java.lang.Object

General file manipulation utilities.

Facilities are provided in the following areas:

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

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

Origin of code: Excalibur, Alexandria, Commons-Utils

Field Summary

Fields

Modifier and Type	Field	Description
static long	ONE_KB	The number of bytes in a kilobyte.
static long	ONE_MB	The number of bytes in a megabyte.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
static void	cleanDirectory(java.io.File directory)	Cleans a directory without deleting it.
static void	copyDirectory(java.io.File srcDir, java.io.File destDir)	Copies a whole directory to a new location preserving the file dates.
static void	copyDirectory(java.io.File srcDir, java.io.File destDir, boolean preserveFileDate)	Copies a whole directory to a new location.
static void	copyDirectory(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter)	Copies a filtered directory to a new location preserving the file dates.
static void	copyDirectory(java.io.File srcDir, java.io.File destDir, java.io.FileFilter filter, boolean preserveFileDate)	Copies a filtered directory to a new location.
static void	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.
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)
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.

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

Constructor Detail

FileUtils

public FileUtils()

Instances should NOT be constructed in standard programming.

Method Detail

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

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

java.io.IOException - if the output file length is not the same as the input file length after the copy completes

Since:

1.3

See Also:

copyFile(File, File, 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

java.io.IOException - if the output file length is not the same as the input file length after the copy completes

See Also:

copyFileToDirectory(File, File), copyFile(File, File, boolean)

copyFile

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

Copies 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

java.io.IOException - if the output file length is not the same as the input file length after the copy completes

See Also:

copyFileToDirectory(File, File, boolean), doCopyFile(File, File, boolean)

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)
                          throws java.io.IOException

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

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

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

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

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

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

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

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

Parameters:

srcDir - an existing directory to copy, must not be null

destDir - the new directory, must not be null

filter - the filter to apply, null means copy all directories and files should be the same as the original

Throws:

java.lang.NullPointerException - if 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

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.

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

  // 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

deleteDirectory

public static void deleteDirectory(java.io.File directory)
                            throws java.io.IOException

Deletes a directory recursively.

Parameters:

directory - directory to delete

Throws:

java.io.IOException - in case deletion is unsuccessful

java.lang.IllegalArgumentException - if directory does not exist or is not a directory

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

java.lang.IllegalArgumentException - if directory does not exist or is not a directory

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

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

isSymlink

public static boolean isSymlink(java.io.File file)
                         throws java.io.IOException

Throws:

java.io.IOException