org.archive.util

Class FileUtils

java.lang.Object

org.archive.util.FileUtils

public class FileUtils
extends Object

Utility methods for manipulating files and directories.

Field Summary

Fields

Modifier and Type	Field and Description
protected static LinkedList<File>	pendingDeletes

Method Summary

Methods

Modifier and Type	Method and Description
static void	appendTo(File fileToAppendTo, File fileToAppendFrom)
static File	assertReadable(File f) Test file exists and is readable.
static boolean	copyFile(File src, File dest) Copy the src file to the destination.
static boolean	copyFile(File src, File dest, long extent) Copy up to extent bytes of the source file to the destination.
static boolean	copyFile(File src, File dest, long extent, boolean overwrite) Copy up to extent bytes of the source file to the destination
static void	deleteSoonerOrLater(File fileToDelete) Delete the file now -- but in the event of failure, keep trying in the future.
static File	ensureWriteableDirectory(File dir) Ensure writeable directory.
static List<File>	ensureWriteableDirectory(List<File> dirs) Ensure writeable directories.
static File	ensureWriteableDirectory(String dir) Ensure writeable directory.
static org.apache.commons.lang.math.LongRange	expandRange(org.apache.commons.lang.math.LongRange range1, org.apache.commons.lang.math.LongRange range2)
static File[]	getFilesWithPrefix(File dir, String prefix) Get a list of all files in directory that have passed prefix.
static org.apache.commons.io.filefilter.IOFileFilter	getRegexFileFilter(String regex) Get a @link java.io.FileFilter that filters files based on a regular expression.
static boolean	isReadableWithExtensionAndMagic(File f, String uncompressedExtension, String magic)
static Properties	loadProperties(File file) Load Properties instance from a File
static File	maybeRelative(File context, String path) Turn path into a File, relative to context (which may be ignored if path is absolute).
static boolean	moveAsideIfExists(File file)
static org.apache.commons.lang.math.LongRange	pagedLines(File file, long position, int signedDesiredLongCount, List<String> lines)
static org.apache.commons.lang.math.LongRange	pagedLines(File file, long position, int signedDesiredLineCount, List<String> lines, int lineEstimate) Retrieve a number of lines from the file around the given position, as when paging forward or backward through a file.
static long	readFullyToFile(InputStream is, File toFile) Read the entire stream to EOF into the passed file.
static void	storeProperties(Properties p, File file) Store Properties instance to a File
static File	tryToCanonicalize(File file)
protected static void	workaroundCopyFile(File src, File dest)

Methods inherited from class java.lang.Object

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

Field Detail

pendingDeletes

protected static LinkedList<File> pendingDeletes

Method Detail

copyFile

public static boolean copyFile(File src,
               File dest)
                        throws FileNotFoundException,
                               IOException

Copy the src file to the destination. Deletes any preexisting file at destination.

Parameters:

src -

dest -

Returns:

True if the extent was greater than actual bytes copied.

Throws:

FileNotFoundException

IOException

copyFile

public static boolean copyFile(File src,
               File dest,
               long extent)
                        throws FileNotFoundException,
                               IOException

Copy up to extent bytes of the source file to the destination. Deletes any preexisting file at destination.

Parameters:

src -

dest -

extent - Maximum number of bytes to copy

Returns:

True if the extent was greater than actual bytes copied.

Throws:

FileNotFoundException

IOException

copyFile

public static boolean copyFile(File src,
               File dest,
               long extent,
               boolean overwrite)
                        throws FileNotFoundException,
                               IOException

Copy up to extent bytes of the source file to the destination

Parameters:

src -

dest -

extent - Maximum number of bytes to copy

overwrite - If target file already exits, and this parameter is true, overwrite target file (We do this by first deleting the target file before we begin the copy).

Returns:

True if the extent was greater than actual bytes copied.

Throws:

FileNotFoundException

IOException

workaroundCopyFile

protected static void workaroundCopyFile(File src,
                      File dest)
                                  throws IOException

Throws:

IOException

getFilesWithPrefix

public static File[] getFilesWithPrefix(File dir,
                        String prefix)

Get a list of all files in directory that have passed prefix.

Parameters:

dir - Dir to look in.

prefix - Basename of files to look for. Compare is case insensitive.

Returns:

List of files in dir that start w/ passed basename.

getRegexFileFilter

public static org.apache.commons.io.filefilter.IOFileFilter getRegexFileFilter(String regex)

Get a @link java.io.FileFilter that filters files based on a regular expression.

Parameters:

regex - the regular expression the files must match.

Returns:

the newly created filter.

assertReadable

public static File assertReadable(File f)
                           throws FileNotFoundException

Test file exists and is readable.

Parameters:

f - File to test.

Throws:

FileNotFoundException - If file does not exist or is not unreadable.

isReadableWithExtensionAndMagic

public static boolean isReadableWithExtensionAndMagic(File f,
                                      String uncompressedExtension,
                                      String magic)
                                               throws IOException

Parameters:

f - File to test.

Returns:

True if file is readable, has uncompressed extension, and magic string at file start.

Throws:

IOException - If file not readable or other problem.

maybeRelative

public static File maybeRelative(File context,
                 String path)

Turn path into a File, relative to context (which may be ignored if path is absolute).

Parameters:

context - File context if path is relative

path - String path to make into a File

Returns:

File created

loadProperties

public static Properties loadProperties(File file)
                                 throws IOException

Load Properties instance from a File

Parameters:

file -

Returns:

Properties

Throws:

IOException

storeProperties

public static void storeProperties(Properties p,
                   File file)
                            throws IOException

Store Properties instance to a File

Parameters:

p -

file - destination File

Throws:

IOException

moveAsideIfExists

public static boolean moveAsideIfExists(File file)
                                 throws IOException

Throws:

IOException

pagedLines

public static org.apache.commons.lang.math.LongRange pagedLines(File file,
                                                long position,
                                                int signedDesiredLineCount,
                                                List<String> lines,
                                                int lineEstimate)
                                                         throws IOException

Retrieve a number of lines from the file around the given position, as when paging forward or backward through a file.

Parameters:

file - File to retrieve lines

position - offset to anchor lines

signedDesiredLineCount - lines requested; if negative, want this number of lines ending with a line containing the position; if positive, want this number of lines, all starting at or after position.

lines - List to insert found lines

lineEstimate - int estimate of line size, 0 means use default of 128

Returns:

LongRange indicating the file offsets corresponding to the beginning of the first line returned, and the point after the end of the last line returned

Throws:

IOException

expandRange

public static org.apache.commons.lang.math.LongRange expandRange(org.apache.commons.lang.math.LongRange range1,
                                                 org.apache.commons.lang.math.LongRange range2)

pagedLines

public static org.apache.commons.lang.math.LongRange pagedLines(File file,
                                                long position,
                                                int signedDesiredLongCount,
                                                List<String> lines)
                                                         throws IOException

Throws:

IOException

deleteSoonerOrLater

public static void deleteSoonerOrLater(File fileToDelete)

Delete the file now -- but in the event of failure, keep trying in the future. VERY IMPORTANT: Do not use with any file whose name/path may be reused, because the lagged delete could then wind up deleting the newer file. Essentially, only to be used with uniquely-named temp files. Necessary because some platforms (looking at you, JVM-on-Windows) will have deletes fail because of things like file-mapped buffers remaining, and there's no explicit way to unmap a buffer. (See 6-year-old Sun-stumping Java bug http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4724038 ) We just have to wait and retry. (Why not just File.deleteOnExit? There could be an arbitrary, unbounded number of files in such a situation, that are only deletable a few seconds or minutes after our first attempt. Waiting for JVM exist could mean disk exhaustion. It's also unclear if the native FS class implementations of deleteOnExit use RAM per pending file.)

Parameters:

fileToDelete -

readFullyToFile

public static long readFullyToFile(InputStream is,
                   File toFile)
                            throws IOException

Read the entire stream to EOF into the passed file. Closes is when done or if an exception.

Parameters:

is - Stream to read.

toFile - File to write to.

Throws:

IOException

ensureWriteableDirectory

public static File ensureWriteableDirectory(String dir)
                                     throws IOException

Ensure writeable directory. If doesn't exist, we attempt creation.

Parameters:

dir - Directory to test for exitence and is writeable.

Returns:

The passed dir.

Throws:

IOException - If passed directory does not exist and is not createable, or directory is not writeable or is not a directory.

ensureWriteableDirectory

public static List<File> ensureWriteableDirectory(List<File> dirs)
                                           throws IOException

Ensure writeable directories. If doesn't exist, we attempt creation.

Parameters:

dirs - List of Files to test.

Returns:

The passed dirs.

Throws:

IOException - If passed directory does not exist and is not createable, or directory is not writeable or is not a directory.

ensureWriteableDirectory

public static File ensureWriteableDirectory(File dir)
                                     throws IOException

Ensure writeable directory. If doesn't exist, we attempt creation.

Parameters:

dir - Directory to test for exitence and is writeable.

Returns:

The passed dir.

Throws:

IOException - If passed directory does not exist and is not createable, or directory is not writeable or is not a directory.

tryToCanonicalize

public static File tryToCanonicalize(File file)

appendTo

public static void appendTo(File fileToAppendTo,
            File fileToAppendFrom)
                     throws IOException

Throws:

IOException