org.esa.beam.util.io
Class FileUtils

java.lang.Object
  org.esa.beam.util.io.FileUtils

public class FileUtils
extends Object

This class provides additional functionality in handling with files. All methods in this class dealing with extensions, expect that an extension is the last part of a file name starting with the dot '.' character.

Version:

$Revision$ $Date$

Author:

Tom Block, Sabine Embacher, Norman Fomferra

Constructor Summary

FileUtils()

Method Summary

static FilenameFilter	createExtensionFilenameFilter(String extension) Creates a file filter which only lets files through which have the given extension.
static String	createValidFilename(String name) Creates a valid filename for the given source name.
static boolean	deleteTree(File tree) Recursively deletes the directory tree.
static File	ensureExtension(File file, String extension) Returns a file with the given extension.
static String	ensureExtension(String path, String extension) Returns a file with the given extension.
static File	exchangeExtension(File file, String extension) Returns a file with the given new extension.
static String	exchangeExtension(String path, String extension) Returns the file string with the given new extension.
static String	getDisplayText(File file, int maxLength)
static String	getExtension(File file) Gets the extension (which always includes a leading dot) of a file.
static String	getExtension(String path) Gets the extension of a file path.
static int	getExtensionDotPos(String path)
static URL	getFileAsUrl(File file) Gets a normalized URL representation for the given file.
static String	getFileNameFromPath(String path) Retrieves the file name from a complete path.
static String	getFilenameWithoutExtension(File file) Gets the filename without its extension from the given file path.
static String	getFilenameWithoutExtension(String fileName) Gets the filename without its extension from the given filename.
static File	getUrlAsFile(URL url) Inverse of getFileAsUrl(java.io.File).
static String[]	listFilePathsWithExtension(File dir, String extension) Lists the filenames with the specified extension contained in the given directory.
static File[]	listFilesWithExtension(File dir, String extension) Lists the files with the specified extension contained in the given directory.
static String	readText(File file)
static String	readText(Reader reader)

Methods inherited from class java.lang.Object

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

Constructor Detail

FileUtils

public FileUtils()

Method Detail

getExtension

public static String getExtension(File file)

Gets the extension (which always includes a leading dot) of a file.

Parameters:

file - the file whose extension is to be extracted.

Returns:

the extension string which always includes a leading dot. Returns null if the file has no extension.

getExtension

public static String getExtension(String path)

Gets the extension of a file path.

Parameters:

path - the file path whose extension is to be extracted.

Returns:

the extension string which always includes a leading dot. Returns null if the file path has no extension.

getFilenameWithoutExtension

public static String getFilenameWithoutExtension(File file)

Gets the filename without its extension from the given file path.

Parameters:

file - the file whose filename is to be extracted.

Returns:

the filename without its extension.

getFilenameWithoutExtension

public static String getFilenameWithoutExtension(String fileName)

Gets the filename without its extension from the given filename.

Parameters:

fileName - the name of the file whose filename is to be extracted.

Returns:

the filename without its extension.

exchangeExtension

public static String exchangeExtension(String path,
                                       String extension)

Returns the file string with the given new extension. If the given file string have no extension, the given extension will be added.

Example1:

 "tie.point.grids\tpg1.hdr" 

results to

 "tie.point.grids\tpg1.raw" 

Example2:

 "tie.point.grids\tpg1" 

results to

 "tie.point.grids\tpg1.raw" 

Parameters:

path - the string to change the extension

extension - the new file extension including a leading dot (e.g. ".raw").

Throws:

IllegalArgumentException - if one of the given strings are null or empty.

exchangeExtension

public static File exchangeExtension(File file,
                                     String extension)

Returns a file with the given new extension. If the given file have no extension, the given extension will be added.

Example1:

 "tie.point.grids\tpg1.hdr" 

results to

 "tie.point.grids\tpg1.raw" 

Example2:

 "tie.point.grids\tpg1" 

results to

 "tie.point.grids\tpg1.raw" 

Parameters:

file - the file to change the extension

extension - the new file extension including a leading dot (e.g. ".raw").

Throws:

IllegalArgumentException - if one of the parameter strings are null or empty.

ensureExtension

public static String ensureExtension(String path,
                                     String extension)

Returns a file with the given extension. If the given path have no extension or the extension are not equal to the given extension, the given extension will be added.

Example1: param path = example.dim param extension = ".dim"

 "example.dim" 

results to

 "example.dim" 

Example2: param path = example param extension = ".dim"

 "example" 

results to

 "example.dim" 

Example3: param path = example.lem param extension = ".dim"

 "example.lem" 

results to

 "example.lem.dim" 

Parameters:

path - the string to ensure the extension

extension - the new file extension including a leading dot (e.g. ".raw").

Throws:

IllegalArgumentException - if one of the given strings are null or empty.

ensureExtension

public static File ensureExtension(File file,
                                   String extension)

Returns a file with the given extension. If the given file has no extension or the extension is not equal to the given extension, the given extension will be added.

Example1: param file = example.dim param extension = ".dim"

 "example.dim" 

results to

 "example.dim" 

Example2: param file = example param extension = ".dim"

 "example" 

results to

 "example.dim" 

Example3: param file = example.lem param extension = ".dim"

 "example.lem" 

results to

 "example.lem.dim" 

Parameters:

file - the file to ensure the extension

extension - the new file extension including a leading dot (e.g. ".raw").

Throws:

IllegalArgumentException - if one of the parameter strings are null or empty.

getExtensionDotPos

public static int getExtensionDotPos(String path)

getFileNameFromPath

public static String getFileNameFromPath(String path)

Retrieves the file name from a complete path. example: "c:/testData/MERIS/meris_test.N1" will be converted to "meris_test.N1"

listFilesWithExtension

public static File[] listFilesWithExtension(File dir,
                                            String extension)

Lists the files with the specified extension contained in the given directory.

See Also:

File.listFiles(), File.listFiles(java.io.FilenameFilter)

listFilePathsWithExtension

public static String[] listFilePathsWithExtension(File dir,
                                                  String extension)

Lists the filenames with the specified extension contained in the given directory.

See Also:

File.list(), File.list(java.io.FilenameFilter)

createExtensionFilenameFilter

public static FilenameFilter createExtensionFilenameFilter(String extension)

Creates a file filter which only lets files through which have the given extension.

See Also:

FilenameFilter

createValidFilename

public static String createValidFilename(String name)

Creates a valid filename for the given source name. The method returns a string which is the given name where each occurence of a character which is not a letter, a digit or one of '_', '-', '.' is replaced by an underscore. The returned string always has the same length as the source name.

Parameters:

name - the source name, must not be null

getFileAsUrl

public static URL getFileAsUrl(File file)
                        throws MalformedURLException

Gets a normalized URL representation for the given file.

Unlike the File.toURL() method, this method automatically escapes characters that are illegal in URLs. It converts the given abstract pathname into a URL by first converting it into a URI, via the File.toURI() method, and then converting the URI into a URL via the URI.toURL method. .

See also the 'Usage Note' of the File.toURL() API documentation.

Parameters:

file - the file

Returns:

a normalized URL representation

Throws:

MalformedURLException

getUrlAsFile

public static File getUrlAsFile(URL url)
                         throws URISyntaxException

Inverse of getFileAsUrl(java.io.File).

Parameters:

url - the URL

Returns:

the file

Throws:

URISyntaxException

getDisplayText

public static String getDisplayText(File file,
                                    int maxLength)

readText

public static String readText(File file)
                       throws IOException

Throws:

IOException

readText

public static String readText(Reader reader)
                       throws IOException

Throws:

IOException

deleteTree

public static boolean deleteTree(File tree)

Recursively deletes the directory tree.

Parameters:

tree - directory to be deleted

Returns:

true if and only if the file or directory is successfully deleted; false otherwise