Package com.peterphi.std.io

Class FileHelper

java.lang.Object

com.peterphi.std.io.FileHelper

public class FileHelper
extends Object

Title: File Helper

Description: File-related helper functions

Copyright: Copyright (c) 2006-2009

Version:

$Revision$

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FileHelper.LockRecord

Method Summary

Modifier and Type	Method	Description
static String	cat(File f)
static String	cat(InputStream is)
static String	cat(Reader reader)
static String	cat(Reader reader, int sizeEstimate)
static String	cat(String filename)
static String	cat(URL u)
static boolean	chmod(File f, int permissions)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions using octal
static boolean	chmod(File f, File copyOf)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions on f with the permissions on copyOf
static boolean	chmod(File f, Set<ChmodBit> set)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie.
static boolean	chmod(File f, Set<ChmodBit> set, Set<ChmodBit> clear)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie.
static boolean	chmod(String as, File f, int permissions)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions using octal
static boolean	chmod(String as, File f, File copyOf)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions on f with the permissions on copyOf
static boolean	chmod(String as, File f, Set<ChmodBit> set)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie.
static boolean	chmod(String as, File f, Set<ChmodBit> set, Set<ChmodBit> clear)	Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie.
static boolean	chown(File f, String owner, String group, boolean recursive)
static void	copy(File src, File dest)
static boolean	couldWrite(File f)
static File	createTempFile(String prefix, String suffix)	Creates a temporary file name
static boolean	delete(File f)	Deletes a local file or directory from the filesystem
static String	enforceSafeFilename(String filename)	Ensures that a file is "safe" (this is done by whitelisting a small number of characters) This method is mainly designed for producing a filename which bears some resemblance to a user-supplied String while removing the risk of being tricked
static boolean	isAbsoluteFile(File f)
static boolean	isAbsoluteFile(String filename)
static boolean	isAncestor(File root, File f)
static FileHelper.LockRecord	lockFile(File f)	Obtains an exclusive lock on the specified file.
static void	mkdirs(File f)	Create a directory and any necessary parent directories, throwing a RuntimeException on failure
static void	move(File src, File dest)
static long	readPID(File f)	Reads a PID (Process Id) file
static long	readPID(File f, boolean carefulProcessing)	Reads a PID (Process Id) file
static boolean	safeMove(File src, File dest)	Deprecated. use commons file utils FileUtils.moveDirectoryToDirectory instead
static boolean	smartEquals(File one, File two, boolean checkName)	Determines if 2 files or directories are equivalent by looking inside them
static void	symlink(File from, File to)
static void	touch(File f)	Creates/updates a file with the modify date set to now
static boolean	trySymlink(File from, File to)
static void	write(File f, Reader fr)
static void	write(File f, String contents)
static void	write(File f, StringBuilder sb)
static void	writePID(File f, long pid)
static void	writePID(File f, String pid)

Methods inherited from class java.lang.Object

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

Method Detail

createTempFile

public static File createTempFile(String prefix,
                                  String suffix)

Creates a temporary file name

Returns:

File

enforceSafeFilename

public static String enforceSafeFilename(String filename)

Ensures that a file is "safe" (this is done by whitelisting a small number of characters)
This method is mainly designed for producing a filename which bears some resemblance to a user-supplied String while removing the risk of being tricked

Parameters:

filename -

Returns:

isAbsoluteFile

public static boolean isAbsoluteFile(File f)

isAbsoluteFile

public static boolean isAbsoluteFile(String filename)

isAncestor

public static boolean isAncestor(File root,
                                 File f)

couldWrite

public static boolean couldWrite(File f)

copy

public static void copy(File src,
                        File dest)
                 throws IOException

Throws:

IOException

move

public static void move(File src,
                        File dest)
                 throws IOException

Throws:

IOException

trySymlink

public static boolean trySymlink(File from,
                                 File to)

symlink

public static void symlink(File from,
                           File to)
                    throws IOException

Throws:

IOException

safeMove

@Deprecated
public static boolean safeMove(File src,
                               File dest)
                        throws SecurityException

Deprecated.

use commons file utils FileUtils.moveDirectoryToDirectory instead

Safely moves a file from one place to another, ensuring the filesystem is left in a consistent state

Parameters:

src - File The source file

dest - File The destination file

Returns:

boolean True if the file has been completely moved to the new location, false if it is still in the original location

Throws:

SecurityException - MAY BE THROWN if permission is denied to src or dest

delete

public static boolean delete(File f)
                      throws IOException

Deletes a local file or directory from the filesystem

Parameters:

f - File The file/directory to delete

Returns:

boolean True if the deletion was a success, otherwise false

Throws:

IOException

smartEquals

public static boolean smartEquals(File one,
                                  File two,
                                  boolean checkName)
                           throws IOException

Determines if 2 files or directories are equivalent by looking inside them

Parameters:

one - File The first file/directory

two - File The second file/directory

checkName - boolean Whether names should be identical also

Returns:

boolean True if the files/directories are equivalent, otherwise false

Throws:

IOException - On an unhandleable error or a non-file, non-directory input

readPID

public static long readPID(File f)
                    throws IOException

Reads a PID (Process Id) file

Parameters:

f - File The process Id file (must exist!)

Returns:

String The process Id represented by the file (or -1 if the file doesn't exist)

Throws:

IOException - On filesystem-level errors

readPID

public static long readPID(File f,
                           boolean carefulProcessing)
                    throws IOException

Reads a PID (Process Id) file

Parameters:

f - File The process Id file (must exist!)

carefulProcessing - boolean If true, non-numeric chars are stripped from the PID before it is parsed

Returns:

String The process Id represented by the file (or -1 if the file doesn't exist)

Throws:

IOException - On filesystem-level errors

writePID

public static void writePID(File f,
                            long pid)
                     throws IOException

Throws:

IOException

writePID

public static void writePID(File f,
                            String pid)
                     throws IOException

Throws:

IOException

write

public static void write(File f,
                         String contents)
                  throws IOException

Throws:

IOException

write

public static void write(File f,
                         StringBuilder sb)
                  throws IOException

Throws:

IOException

write

public static void write(File f,
                         Reader fr)
                  throws IOException

Throws:

IOException

cat

public static String cat(String filename)
                  throws IOException

Throws:

IOException

cat

public static String cat(InputStream is)
                  throws IOException

Throws:

IOException

cat

public static String cat(URL u)
                  throws IOException

Throws:

IOException

cat

public static String cat(Reader reader)
                  throws IOException

Throws:

IOException

cat

public static String cat(File f)
                  throws IOException

Throws:

IOException

cat

public static String cat(Reader reader,
                         int sizeEstimate)
                  throws IOException

Throws:

IOException

chown

public static boolean chown(File f,
                            String owner,
                            String group,
                            boolean recursive)
                     throws IOException

Throws:

IOException

chmod

public static boolean chmod(File f,
                            int permissions)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions using octal

Parameters:

f -

permissions - REMEMBER TO SPECIFY THIS VALUE IN OCTAL (ie. with a leading zero) IF YOU ARE USING NUMBERS IDENTICAL TO THE CHMOD COMMAND-LINE REPRESENTATION (eg. 755)

Returns:

Throws:

IOException

chmod

public static boolean chmod(String as,
                            File f,
                            int permissions)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions using octal

Parameters:

f -

permissions - REMEMBER TO SPECIFY THIS VALUE IN OCTAL (ie. with a leading zero)

Returns:

Throws:

IOException

chmod

public static boolean chmod(File f,
                            File copyOf)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions on f with the permissions on copyOf

Parameters:

f -

copyOf - the file to use the permissions from

Returns:

Throws:

IOException

chmod

public static boolean chmod(String as,
                            File f,
                            File copyOf)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), replacing the permissions on f with the permissions on copyOf

Parameters:

f -

copyOf - the file to use the permissions from

Returns:

Throws:

IOException

chmod

public static boolean chmod(String as,
                            File f,
                            Set<ChmodBit> set)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie. chmod o+w)

Parameters:

f -

set - The permissions to set on the file

Returns:

Throws:

IOException

chmod

public static boolean chmod(File f,
                            Set<ChmodBit> set)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie. chmod o+w)

Parameters:

f -

set - The permissions to set on the file

Returns:

Throws:

IOException

chmod

public static boolean chmod(File f,
                            Set<ChmodBit> set,
                            Set<ChmodBit> clear)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie. chmod o+w)

Parameters:

f -

set - The permissions to set on the file

clear - The permissions to modify on the file

Returns:

Throws:

IOException

chmod

public static boolean chmod(String as,
                            File f,
                            Set<ChmodBit> set,
                            Set<ChmodBit> clear)

Performs a chmod (which assumes this system is Linux/UNIX/Solaris/etc), altering the permissions using symbols (ie. chmod o+w)

Parameters:

f -

set - The permissions to set on the file

clear - The permissions to modify on the file

Returns:

Throws:

IOException

lockFile

public static FileHelper.LockRecord lockFile(File f)

Obtains an exclusive lock on the specified file. By calling this method, the caller guarantees it will call the release() method of the LockRecord

Parameters:

f - File The file to lock

Returns:

LockRecord The lock record

touch

public static void touch(File f)
                  throws IOException

Creates/updates a file with the modify date set to now

Parameters:

f -

Throws:

IOException

mkdirs

public static void mkdirs(File f)

Create a directory and any necessary parent directories, throwing a RuntimeException on failure

Parameters:

f - the directory to create

Throws:

RuntimeException - wrapping the inner IOException if the filesystem cannot create a directory