uk.ac.ed.inf.utils
Class FileUtils

java.lang.Object
  uk.ac.ed.inf.utils.FileUtils

public class FileUtils
extends java.lang.Object

Utils to read, write files etc.

Version:

24-Mar-2007

Author:

ldeferra

Constructor Summary

FileUtils()

Method Summary

static void	appendPropertiesToFile(java.io.File file, java.util.Properties properties)
static void	appendToFile(java.io.File file, java.lang.String text) Append text to file
static void	appendToFile(java.lang.String filePath, java.lang.String text) Append text to file
static void	appendToFileAndPrint(java.lang.String filePath, java.lang.String text) Append print text to screen (system.out) and append it to file.
static boolean	canReadFile(java.io.File file) Tests wether the file can be read
static boolean	canReadFile(java.lang.String path) Tests whether the file can be read
static boolean	canReadParent(java.lang.String path) Checks whether a file directory is readable.
static boolean	canWriteFile(java.io.File file) Tests whether the file can be written
static boolean	canWriteFile(java.lang.String path) Tests wether the file can be written
static boolean	canWriteParent(java.lang.String path) Checks whether a file directory is writable.
static boolean	deleteFile(java.lang.String fileName) Delete a file
static void	fileNotWritablePopUp(java.lang.String filePath) Error Pop-up: file not writable
static java.lang.String[][]	fileToArrayOfArrays(java.lang.String fileName, java.lang.String regExpOfSeparator, boolean discardFirstLine) Reads a special-character-separated file (eg comma or tab separated) and creates an array of rows-columns.
static java.util.ArrayList<java.lang.String>	fileToArrayOfLines(java.io.File file) Reads a file and adds the lines to an array, adapted from: http://www.computing.net/programming/wwwboard/forum/12276.html
static java.util.ArrayList<java.lang.String>	fileToArrayOfLines(java.lang.String filePath) Reads a file and adds the lines to an array, adapted from: http://www.computing.net/programming/wwwboard/forum/12276.html
static java.util.ArrayList<java.lang.String>	fileTokensToArray(java.lang.String fileName, java.lang.String regexp) Reads a file and adds the tokens (identified by regular expressions) to an array (e.g.
static void	fromArrayOfArraysToFile(java.util.ArrayList<java.util.ArrayList<java.lang.String>> lists, java.lang.String fileName, java.lang.String regExpOfSeparator) Writes a special-character-separated file (eg comma or tab separated) and fills it from an array of rows-columns.
static java.io.BufferedReader	fromFilePathToBufferedReader(java.lang.String filePath) From file path to bufferedReader
static java.lang.String[]	getDirectoryFiles(java.lang.String directoryPath) Gets the list of files in a directory From http://www.faqs.org/docs/javap/c10/s2.html
static java.lang.String	getDirectoryPath(java.lang.String path) Get the parent of a full file path (directory + filename)
static java.lang.String	getFileNameFromDirectory(java.lang.String directoryPath, java.lang.String pattern) Get the first file name in the directory matching the given pattern string.
static java.lang.String	getFileNameFromFullPath(java.lang.String path) Get the filename from a full file path (directory + filename)
static long	getFileSizeInKb(java.lang.String filePath) Get the file size in Kb
static java.util.zip.GZIPInputStream	getGunzipInputStream(java.io.BufferedInputStream source)
static java.io.File	getPotentialDirectory(java.io.File file) Get a directory out of a path
static java.lang.String	getStringFromBufferedReader(java.io.BufferedReader reader)
static java.lang.String	getStringFromFile(java.lang.String filePath) Get all the text in a file as a single string
static java.util.zip.GZIPInputStream	gunzipFile(java.io.File inputFile)
static int	gunzipFile2(java.io.File file_input, java.io.File dir_output) Gunzip the input archive.
static void	main(java.lang.String[] args) Main method for testing
static void	printAllPaths(java.io.File file) Test method to print all absolute/relative paths of a file
static void	printFromReader(java.io.BufferedReader reader) Prints all lines from a reader.
static void	writeToFile(java.lang.String filePath, java.lang.String text)

Methods inherited from class java.lang.Object

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

Constructor Detail

FileUtils

public FileUtils()

Method Detail

appendPropertiesToFile

public static void appendPropertiesToFile(java.io.File file,
                                          java.util.Properties properties)

appendToFile

public static void appendToFile(java.io.File file,
                                java.lang.String text)

Append text to file

Parameters:

file - a File object

text - a text string

Throws:

java.io.IOException

appendToFile

public static void appendToFile(java.lang.String filePath,
                                java.lang.String text)

Append text to file

Parameters:

filePath - the full path to an existing file

text - a text string

appendToFileAndPrint

public static void appendToFileAndPrint(java.lang.String filePath,
                                        java.lang.String text)

Append print text to screen (system.out) and append it to file.

Parameters:

filePath - the full path to an existing file

text - a text string

canReadFile

public static boolean canReadFile(java.io.File file)

Tests wether the file can be read

canReadFile

public static boolean canReadFile(java.lang.String path)

Tests whether the file can be read

canReadParent

public static boolean canReadParent(java.lang.String path)

Checks whether a file directory is readable. For example for file /home/user/file.txt, it checks if /home/user/ is readable

Parameters:

path - directory path + filename

Returns:

true if the path before the last slash is readable

canWriteFile

public static boolean canWriteFile(java.io.File file)

Tests whether the file can be written

canWriteFile

public static boolean canWriteFile(java.lang.String path)

Tests wether the file can be written

canWriteParent

public static boolean canWriteParent(java.lang.String path)

Checks whether a file directory is writable. For example for file /home/user/file.txt, it checks if /home/user/ is writable

Parameters:

path - directory path + filename

Returns:

true if the path before the last slash is writable

deleteFile

public static boolean deleteFile(java.lang.String fileName)

Delete a file

Parameters:

filePath - the full path to a file

Returns:

true if the file was deleted

fileNotWritablePopUp

public static void fileNotWritablePopUp(java.lang.String filePath)

Error Pop-up: file not writable

fileToArrayOfArrays

public static java.lang.String[][] fileToArrayOfArrays(java.lang.String fileName,
                                                       java.lang.String regExpOfSeparator,
                                                       boolean discardFirstLine)

Reads a special-character-separated file (eg comma or tab separated) and creates an array of rows-columns. Each column contains the column data elements

Parameters:

fileName - the full path to the file to be read

regExpOfSeparator - the regular expression separating the tokens in the line (e.g. a comma for comma separated values files)

Returns:

an array of arrays in which each element is a token from the file (row by columns)

fileToArrayOfLines

public static java.util.ArrayList<java.lang.String> fileToArrayOfLines(java.io.File file)

Reads a file and adds the lines to an array, adapted from: http://www.computing.net/programming/wwwboard/forum/12276.html

Parameters:

file - the file to read from

Returns:

the array containing the file lines

fileToArrayOfLines

public static java.util.ArrayList<java.lang.String> fileToArrayOfLines(java.lang.String filePath)

Reads a file and adds the lines to an array, adapted from: http://www.computing.net/programming/wwwboard/forum/12276.html

Parameters:

filePath - the path of the file to read from

Returns:

the array containing the file lines

fileTokensToArray

public static java.util.ArrayList<java.lang.String> fileTokensToArray(java.lang.String fileName,
                                                                      java.lang.String regexp)

Reads a file and adds the tokens (identified by regular expressions) to an array (e.g. for flat files with a long list of values _without_ any new-line) adapted from: http://www.computing.net/programming/wwwboard/forum/12276.html

Parameters:

fileName - the path of the file to read from

Returns:

array with the string tokens

fromArrayOfArraysToFile

public static void fromArrayOfArraysToFile(java.util.ArrayList<java.util.ArrayList<java.lang.String>> lists,
                                           java.lang.String fileName,
                                           java.lang.String regExpOfSeparator)
                                    throws java.io.IOException

Writes a special-character-separated file (eg comma or tab separated) and fills it from an array of rows-columns. Each column contains the column data elements

Parameters:

fileName - the file to be read

regExpOfSeparator - the regular expression separating the tokens in the line (e.g. a comma for comma separated values files)

Throws:

java.io.IOException

fromFilePathToBufferedReader

public static java.io.BufferedReader fromFilePathToBufferedReader(java.lang.String filePath)

From file path to bufferedReader

Parameters:

filePath -

Returns:

a BufferedReader

Throws:

java.io.FileNotFoundException

getDirectoryFiles

public static java.lang.String[] getDirectoryFiles(java.lang.String directoryPath)

Gets the list of files in a directory From http://www.faqs.org/docs/javap/c10/s2.html

Parameters:

directoryPath -

Returns:

a list of files in the directory

getDirectoryPath

public static java.lang.String getDirectoryPath(java.lang.String path)

Get the parent of a full file path (directory + filename)

Parameters:

path - a full file path (directory + filename)

Returns:

the parent directory full path

getFileNameFromDirectory

public static java.lang.String getFileNameFromDirectory(java.lang.String directoryPath,
                                                        java.lang.String pattern)

Get the first file name in the directory matching the given pattern string.

Parameters:

pattern - a regular expression

Returns:

the path of the first file matching the pattern

getFileNameFromFullPath

public static java.lang.String getFileNameFromFullPath(java.lang.String path)

Get the filename from a full file path (directory + filename)

Parameters:

path - a full file path (directory + filename)

Returns:

the filename (string after the last slash or backslash)

getFileSizeInKb

public static long getFileSizeInKb(java.lang.String filePath)

Get the file size in Kb

getGunzipInputStream

public static java.util.zip.GZIPInputStream getGunzipInputStream(java.io.BufferedInputStream source)

getPotentialDirectory

public static java.io.File getPotentialDirectory(java.io.File file)

Get a directory out of a path

getStringFromBufferedReader

public static java.lang.String getStringFromBufferedReader(java.io.BufferedReader reader)

getStringFromFile

public static java.lang.String getStringFromFile(java.lang.String filePath)

Get all the text in a file as a single string

Parameters:

filePath -

Returns:

all the text in the file as a single string

Throws:

java.io.IOException

gunzipFile

public static java.util.zip.GZIPInputStream gunzipFile(java.io.File inputFile)

gunzipFile2

public static int gunzipFile2(java.io.File file_input,
                              java.io.File dir_output)

Gunzip the input archive. Send the output to the directory specified by dir_output. Assumes that the input file name ends with ".gz" from http://www .particle.kth.se/~lindsey/JavaCourse/Book/Part1/Supplements/Chapter09 /compressDecompress.html

main

public static void main(java.lang.String[] args)

Main method for testing

Parameters:

args -

Throws:

java.sql.SQLException

printAllPaths

public static void printAllPaths(java.io.File file)
                          throws java.io.IOException

Test method to print all absolute/relative paths of a file

Parameters:

file -

Throws:

java.io.IOException

printFromReader

public static void printFromReader(java.io.BufferedReader reader)
                            throws java.io.IOException

Prints all lines from a reader.

Parameters:

reader - a buffered reader object (taking text from a file, or URL etc.)

Throws:

java.io.IOException

writeToFile

public static void writeToFile(java.lang.String filePath,
                               java.lang.String text)