de.lmu.ifi.dbs.elki.utilities
Class FileUtil

java.lang.Object
  de.lmu.ifi.dbs.elki.utilities.FileUtil

public final class FileUtil
extends Object

Various static helper methods to deal with files and file names.

Author:

Erich Schubert

Constructor Summary

FileUtil()

Method Summary

static String	getFilenameExtension(File file) Returns the lower case extension of the selected file.
static String	getFilenameExtension(String name) Returns the lower case extension of the selected file.
static File	locateFile(String name, String basedir) Try to locate an file in the filesystem, given a partial name and a prefix.
static InputStream	openSystemFile(String filename) Try to open a file, first trying the file system, then falling back to the classpath.
static InputStream	tryGzipInput(InputStream in) Try to open a stream as gzip, if it starts with the gzip magic.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileUtil

public FileUtil()

Method Detail

getFilenameExtension

public static String getFilenameExtension(File file)

Returns the lower case extension of the selected file. If no file is selected, null is returned.

Parameters:

file - File object

Returns:

Returns the extension of the selected file in lower case or null

getFilenameExtension

public static String getFilenameExtension(String name)

Returns the lower case extension of the selected file. If no file is selected, null is returned.

Parameters:

name - File name

Returns:

Returns the extension of the selected file in lower case or null

openSystemFile

public static InputStream openSystemFile(String filename)
                                  throws FileNotFoundException

Try to open a file, first trying the file system, then falling back to the classpath.

Parameters:

filename - File name in system notation

Returns:

Input stream

Throws:

FileNotFoundException - When no file was found.

tryGzipInput

public static InputStream tryGzipInput(InputStream in)
                                throws IOException

Try to open a stream as gzip, if it starts with the gzip magic. TODO: move to utils package.

Parameters:

in - original input stream

Returns:

old input stream or a GZIPInputStream if appropriate.

Throws:

IOException - on IO error

locateFile

public static File locateFile(String name,
                              String basedir)

Try to locate an file in the filesystem, given a partial name and a prefix.

Parameters:

name - file name

basedir - extra base directory to try

Returns:

file, if the file could be found. null otherwise