ai.libs.jaicore.basic

Class FileUtil

java.lang.Object

ai.libs.jaicore.basic.FileUtil

public class FileUtil
extends java.lang.Object

Util class for handling file I/O.

Method Summary

Modifier and Type	Method and Description
static void	deleteFolderRecursively(java.io.File dir) Helper method to delete non-empty folders, i.e., recursively deleting all contained files and sub-folders.
static java.io.File	getExistingFileWithHighestPriority(java.lang.String resourcePath, java.lang.String... fileSystemPaths) Returns the file for a given path with the highest priority which also exists; the resource path is the backup solution with lowest priority.
static java.util.List<java.io.File>	getFilesOfFolder(java.io.File folder) Returns a list of files contained in the specified folder.
static boolean	move(java.io.File from, java.io.File to) This operation moves a file "from" to a destination "to".
static boolean	move(java.lang.String from, java.lang.String to) Moves the path "from" to a destination path "to".
static java.util.List<java.lang.String>	readFileAsList(java.io.File file) Reads the content of the given file as a list of strings.
static java.util.List<java.lang.String>	readFileAsList(java.lang.String filename) Reads the content of the given file as a list of strings.
static java.util.List<java.util.List<java.lang.String>>	readFileAsMatrix(java.lang.String filename, java.lang.String separation) Reads the content of the given file as a matrix of string which are separated by the given separation string.
static java.lang.String	readFileAsString(java.io.File file) Reads the content of the given file into a single string.
static java.lang.String	readFileAsString(java.lang.String filename) Reads the content of the given file into a single string.
static java.util.Properties	readPropertiesFile(java.io.File propertiesFile) Reads the given file into a Properties object.
static void	requireFileExists(java.io.File file) Checks whetehr a given file exists and if so, whether it is actually a file and not a directory.
static void	serializeObject(java.lang.Object object, java.lang.String pathname) This method helps to serialize class objects as files.
static void	touch(java.lang.String filename) Creates an empty file for the given path if it does not already exist.
static java.lang.Object	unserializeObject(java.lang.String pathname) This method can be used to unserialize an object from disk (located at the specified path) and restore the original object.
static void	zipFiles(java.util.Collection<java.lang.String> files, java.lang.String archive) Archives a collection of files specified by their paths into a zip-file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

readFileAsList

public static java.util.List<java.lang.String> readFileAsList(java.io.File file)
                                                       throws java.io.IOException

Reads the content of the given file as a list of strings.

Parameters:

file - The file to be read.

Returns:

The list of strings representing the content of the file.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

readFileAsList

public static java.util.List<java.lang.String> readFileAsList(java.lang.String filename)
                                                       throws java.io.IOException

Reads the content of the given file as a list of strings.

Parameters:

filename - The path to the file to be read.

Returns:

The list of strings representing the content of the file.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

readFileAsString

public static java.lang.String readFileAsString(java.io.File file)
                                         throws java.io.IOException

Reads the content of the given file into a single string.

Parameters:

file - The file to be read.

Returns:

The String representing the content of the file.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

readFileAsString

public static java.lang.String readFileAsString(java.lang.String filename)
                                         throws java.io.IOException

Reads the content of the given file into a single string.

Parameters:

filename - The path to the file to be read.

Returns:

The String representing the content of the file.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

readFileAsMatrix

public static java.util.List<java.util.List<java.lang.String>> readFileAsMatrix(java.lang.String filename,
                                                                                java.lang.String separation)
                                                                         throws java.io.IOException

Reads the content of the given file as a matrix of string which are separated by the given separation string.

Parameters:

filename - The path to the file to be read.

separation - The string separating the matrix entries of a row.

Returns:

The matrix of strings.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

readPropertiesFile

public static java.util.Properties readPropertiesFile(java.io.File propertiesFile)
                                               throws java.io.IOException

Reads the given file into a Properties object.

Parameters:

propertiesFile - The file to be read.

Returns:

The properties object loaded from the specified file.

Throws:

java.io.IOException - Thrown, if there are issues reading the file.

zipFiles

public static void zipFiles(java.util.Collection<java.lang.String> files,
                            java.lang.String archive)
                     throws java.io.IOException

Archives a collection of files specified by their paths into a zip-file.

Parameters:

files - The files to be archived in a zip file.

archive - The path to output the zipped files.

Throws:

java.io.IOException - Thrown, if an issue occurs while creating zip entries or writing the zip file to disk.

serializeObject

public static void serializeObject(java.lang.Object object,
                                   java.lang.String pathname)
                            throws java.io.IOException

This method helps to serialize class objects as files.

Parameters:

object - The object to be serialized.

pathname - The path where to store the serialized object.

Throws:

java.io.IOException - Thrown if the object cannot be serialized or the serialized object cannot be written to disk.

unserializeObject

public static java.lang.Object unserializeObject(java.lang.String pathname)
                                          throws java.io.IOException,
                                                 java.lang.ClassNotFoundException

This method can be used to unserialize an object from disk (located at the specified path) and restore the original object.

Parameters:

pathname - The path from where to unserialize the object.

Returns:

The unserialized object.

Throws:

java.io.IOException - Thrown, if the binary file cannot be read.

java.lang.ClassNotFoundException - Thrown, if the class of the object which is unserialized cannot be found on the classpath.

touch

public static void touch(java.lang.String filename)

Creates an empty file for the given path if it does not already exist.

Parameters:

filename - The path of the file.

move

public static boolean move(java.io.File from,
                           java.io.File to)

This operation moves a file "from" to a destination "to".

Parameters:

from - The original file.

to - The destination of the file.

Returns:

Returns true, iff the move operation was successful.

move

public static boolean move(java.lang.String from,
                           java.lang.String to)

Moves the path "from" to a destination path "to".

Parameters:

from - The original path.

to - The destination path where to move the original path to.

Returns:

Returns true, iff the move operation was successful.

getFilesOfFolder

public static java.util.List<java.io.File> getFilesOfFolder(java.io.File folder)

Returns a list of files contained in the specified folder.

Parameters:

folder - The folder for which the list of files shall be returned.

Returns:

A list of files contained in the given folder.

requireFileExists

public static void requireFileExists(java.io.File file)
                              throws FileIsDirectoryException,
                                     java.io.FileNotFoundException

Checks whetehr a given file exists and if so, whether it is actually a file and not a directory.

Parameters:

file - The file to be checked.

Throws:

FileIsDirectoryException - Is thrown if the file exists but is a directory.

java.io.FileNotFoundException - Is thrown if there exists no such file.

getExistingFileWithHighestPriority

public static java.io.File getExistingFileWithHighestPriority(java.lang.String resourcePath,
                                                              java.lang.String... fileSystemPaths)

Returns the file for a given path with the highest priority which also exists; the resource path is the backup solution with lowest priority. The getter iterates over the fileSytemPaths array and returns the first existing file, i.e. paths with a lower array index have higher priority. If there is no element in the array or none of the given paths exists as a file, the file corresponding to the resource path will be returned as a fall-back, i.e., the resource path has the lowest priority.

Parameters:

resourcePath - The resource path that is to be taken as a fall-back.

fileSystemPaths - An array of paths with descending priority.

Returns:

The existing file with highest priority.

deleteFolderRecursively

public static void deleteFolderRecursively(java.io.File dir)
                                    throws java.io.IOException

Helper method to delete non-empty folders, i.e., recursively deleting all contained files and sub-folders.

Parameters:

dir - The folder to be deleted.

Throws:

java.io.IOException - Thrown, if there an issue arises while deleting all the files and sub-folders.