com.ibm.bluej.util.common

Class FileUtil

java.lang.Object

com.ibm.bluej.util.common.FileUtil

public class FileUtil
extends java.lang.Object

When reading from or writing to a file, a filename ending with .gz indicates the file is/should-be gzipped for any write method, if any directories need to be created to write the file, they should be created automatically the methods should not throw checked exceptions, if there is an I/O problem, they throw an Error

Author:

psuryan, mchowdh (added a method to enable appending text to an existing file)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FileUtil.FileIterable
static class	FileUtil.FileIterator

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	EXTN_CHR
static java.lang.String	GZIP_EXTN

Constructor Summary

Constructors

Constructor and Description
FileUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static void	appendText(java.lang.String content, java.io.File outFile) Appends text in an existing file.
static void	appendText(java.lang.String content, java.lang.String outFileName) Appends text in an existing file.
static java.lang.String	bytesToString(byte[] bs)
static void	checkReadableOrThrowError(java.lang.String description, java.lang.String path) Ensure that a path exists and is readable, otherwise throw a RuntimeException using a description of the path.
static void	closeOutputStream(java.io.OutputStream os)
static java.lang.String	ensureSlash(java.lang.String dirPath) if the dirPath ends in a '/' it does nothing otherwise it adds a '/'
static void	ensureWorldReadable(java.io.File f)
static void	ensureWriteable(java.io.File f) creates any directories that need to exist to create and write the file should not create the file
static boolean	exists(java.lang.String path) Return true if the file exists
static java.io.InputStream	fastStream(java.io.File file) get an input stream for the file that is fast, trading memory for speed
static java.lang.String	getCanonicalPath(java.io.File file) gets the canonical path for the file, or null if it cannot
static java.lang.String	getCanonicalPath(java.lang.String path)
static java.io.DataInputStream	getDataInput(java.lang.String filename)
static java.io.DataOutputStream	getDataOutput(java.lang.String filename)
static java.lang.String	getExtension(java.lang.String fileName) return the last extension from a filename, including the '.'
static java.io.PrintStream	getFilePrintStream(java.lang.String filename) constructs PrintStream to write to the file called filename, creating any parent directories, and gzipping the output if the filename ends with ".gz"
static java.lang.Iterable<java.lang.String>	getLines(java.lang.String filename)
static java.lang.Iterable<java.lang.String>	getRawLines(java.lang.String filename)
static <T> T	loadObjectFromFile(java.io.File file) assume the file contains exactly one serialized object, read it and return it if the file doesn't exist, they return null
static <T> T	loadObjectFromFile(java.lang.String fileName) Given a fileName, assume the file contains exactly one serialized object, read it and return it if the file doesn't exist, they return null
static java.lang.String	readFileAsString(java.io.File file) read the contents of the file into a string and return it if the file doesn't exist, they return null = * Based on https://weblogs.java.net/blog/pat/archive/2004/10/stupid_scanner_1.html (APACHE LICENSE)
static java.lang.String	readFileAsString(java.lang.String filename) read the contents of the file into a string and return it
static java.lang.String	readProcessAsString(java.lang.Process proc) read the stdout of the process into a string and return when the function returns the process has completed the stderr of the process is ignored
static java.lang.String	readResourceAsString(java.lang.String resource)
static java.lang.String	readStreamAsString(java.io.InputStream is) reads the input stream into a String and closes it
static java.lang.String	removeExtension(java.lang.String fileName) remove the last extension from a file If it is a directory, then return the name If it is a hidden file without extn, return the name If it is a hidden file with extn, return name sans extn If is a regular file with extn, return the name sans extn
static java.lang.String	removeExtensions(java.lang.String file) removes the '.whatever.txt.gz' at the end of the file.
static void	saveObjectAsFile(java.io.File file, java.lang.Object object) save the presumably Serializable object to the file
static void	saveObjectAsFile(java.lang.String fileName, java.lang.Object object) save the presumably Serializable object to the file, given a fileName
static byte[]	stringToBytes(java.lang.String str)
static void	writeFileAsString(java.io.File file, java.lang.String text) writes the text to the file wither compressed or uncompressed
static void	writeFileAsString(java.lang.String filename, java.lang.String text) writes the text to the file, given a fileName and text

Methods inherited from class java.lang.Object

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

Field Detail

GZIP_EXTN

public static java.lang.String GZIP_EXTN

EXTN_CHR

public static java.lang.String EXTN_CHR

Constructor Detail

FileUtil

public FileUtil()

Method Detail

writeFileAsString

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

writes the text to the file wither compressed or uncompressed

Parameters:

file -

text -

writeFileAsString

public static void writeFileAsString(java.lang.String filename,
                     java.lang.String text)

writes the text to the file, given a fileName and text

Parameters:

filename -

text -

ensureWriteable

public static void ensureWriteable(java.io.File f)

creates any directories that need to exist to create and write the file should not create the file

readFileAsString

public static java.lang.String readFileAsString(java.lang.String filename)

read the contents of the file into a string and return it

Parameters:

filename -

Returns:

file contents as String

readFileAsString

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

read the contents of the file into a string and return it if the file doesn't exist, they return null = * Based on https://weblogs.java.net/blog/pat/archive/2004/10/stupid_scanner_1.html (APACHE LICENSE)

Parameters:

file -

Returns:

file contents as String

readStreamAsString

public static java.lang.String readStreamAsString(java.io.InputStream is)

reads the input stream into a String and closes it

Parameters:

is -

Returns:

stream contents as String

saveObjectAsFile

public static void saveObjectAsFile(java.io.File file,
                    java.lang.Object object)

save the presumably Serializable object to the file

Parameters:

file -

object -

saveObjectAsFile

public static void saveObjectAsFile(java.lang.String fileName,
                    java.lang.Object object)

save the presumably Serializable object to the file, given a fileName

Parameters:

file -

object -

loadObjectFromFile

public static <T> T loadObjectFromFile(java.io.File file)

assume the file contains exactly one serialized object, read it and return it if the file doesn't exist, they return null

Parameters:

file -

Returns:

object of type T

loadObjectFromFile

public static <T> T loadObjectFromFile(java.lang.String fileName)

Given a fileName, assume the file contains exactly one serialized object, read it and return it if the file doesn't exist, they return null

Parameters:

file -

Returns:

object of type T

removeExtension

public static java.lang.String removeExtension(java.lang.String fileName)

remove the last extension from a file If it is a directory, then return the name If it is a hidden file without extn, return the name If it is a hidden file with extn, return name sans extn If is a regular file with extn, return the name sans extn

Parameters:

fileName -

Returns:

fileName without extension

removeExtensions

public static java.lang.String removeExtensions(java.lang.String file)

removes the '.whatever.txt.gz' at the end of the file. If the file has multiple extensions it removes them all.

Parameters:

file -

Returns:

getExtension

public static java.lang.String getExtension(java.lang.String fileName)

return the last extension from a filename, including the '.'

Parameters:

fileName -

ensureSlash

public static java.lang.String ensureSlash(java.lang.String dirPath)

if the dirPath ends in a '/' it does nothing otherwise it adds a '/'

Parameters:

dirPath -

Returns:

exists

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

Return true if the file exists

Parameters:

path -

Returns:

true of false

getCanonicalPath

public static java.lang.String getCanonicalPath(java.io.File file)

gets the canonical path for the file, or null if it cannot

Parameters:

file -

Returns:

the canonical path

fastStream

public static java.io.InputStream fastStream(java.io.File file)

get an input stream for the file that is fast, trading memory for speed

Parameters:

file -

Returns:

InputStream

readProcessAsString

public static java.lang.String readProcessAsString(java.lang.Process proc)
                                            throws java.lang.InterruptedException

read the stdout of the process into a string and return when the function returns the process has completed the stderr of the process is ignored

Parameters:

proc -

Returns:

String

Throws:

java.lang.InterruptedException

getFilePrintStream

public static java.io.PrintStream getFilePrintStream(java.lang.String filename)

constructs PrintStream to write to the file called filename, creating any parent directories, and gzipping the output if the filename ends with ".gz"

Parameters:

filename -

Returns:

getRawLines

public static java.lang.Iterable<java.lang.String> getRawLines(java.lang.String filename)

getLines

public static java.lang.Iterable<java.lang.String> getLines(java.lang.String filename)

readResourceAsString

public static java.lang.String readResourceAsString(java.lang.String resource)

getDataOutput

public static java.io.DataOutputStream getDataOutput(java.lang.String filename)

getDataInput

public static java.io.DataInputStream getDataInput(java.lang.String filename)

ensureWorldReadable

public static void ensureWorldReadable(java.io.File f)

closeOutputStream

public static void closeOutputStream(java.io.OutputStream os)

stringToBytes

public static byte[] stringToBytes(java.lang.String str)

bytesToString

public static java.lang.String bytesToString(byte[] bs)

checkReadableOrThrowError

public static void checkReadableOrThrowError(java.lang.String description,
                             java.lang.String path)

Ensure that a path exists and is readable, otherwise throw a RuntimeException using a description of the path.

getCanonicalPath

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

appendText

public static void appendText(java.lang.String content,
              java.lang.String outFileName)
                       throws java.io.IOException

Appends text in an existing file. If the file does not exist, a new file is created.

Parameters:

content -

outFile -

Throws:

java.io.IOException

appendText

public static void appendText(java.lang.String content,
              java.io.File outFile)
                       throws java.io.IOException

Appends text in an existing file. If the file does not exist, a new file is created.

Parameters:

content -

outFile -

Throws:

java.io.IOException