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// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
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//
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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package jodd.io;
import jodd.util.SystemUtil;
import jodd.util.StringPool;
import java.io.File;
/**
* General filename and filepath manipulation utilities.
*
* When dealing with filenames you can hit problems when moving from a Windows
* based development machine to a Unix based production machine.
* This class aims to help avoid those problems.
*
* NOTE: You may be able to avoid using this class entirely simply by
* using JDK {@link java.io.File File} objects and the two argument constructor
* {@link java.io.File#File(java.io.File, java.lang.String) File(File,String)}.
*
* Most methods on this class are designed to work the same on both Unix and Windows.
* Those that don't include 'System', 'Unix' or 'Windows' in their name.
*
* Most methods recognise both separators (forward and back), and both
* sets of prefixes. See the javadoc of each method for details.
*
* This class defines six components within a filename
* (example C:\dev\project\file.txt):
*
* - the prefix - C:\
* - the path - dev\project\
* - the full path - C:\dev\project\
* - the name - file.txt
* - the base name - file
* - the extension - txt
*
* Note that this class works best if directory filenames end with a separator.
* If you omit the last separator, it is impossible to determine if the filename
* corresponds to a file or a directory. As a result, we have chosen to say
* it corresponds to a file.
*
* This class only supports Unix and Windows style names.
* Prefixes are matched as follows:
*
{@code
* Windows:
* a\b\c.txt --> "" --> relative
* \a\b\c.txt --> "\" --> current drive absolute
* C:a\b\c.txt --> "C:" --> drive relative
* C:\a\b\c.txt --> "C:\" --> absolute
* \\server\a\b\c.txt --> "\\server\" --> UNC
*
* Unix:
* a/b/c.txt --> "" --> relative
* /a/b/c.txt --> "/" --> absolute
* ~/a/b/c.txt --> "~/" --> current user
* ~ --> "~/" --> current user (slash added)
* ~user/a/b/c.txt --> "~user/" --> named user
* ~user --> "~user/" --> named user (slash added)
* }
* Both prefix styles are matched always, irrespective of the machine that you are
* currently running on.
*/
public class FileNameUtil {
/**
* The extension separator character.
*/
private static final char EXTENSION_SEPARATOR = '.';
/**
* The Unix separator character.
*/
private static final char UNIX_SEPARATOR = '/';
/**
* The Windows separator character.
*/
private static final char WINDOWS_SEPARATOR = '\\';
/**
* The system separator character.
*/
private static final char SYSTEM_SEPARATOR = File.separatorChar;
/**
* The separator character that is the opposite of the system separator.
*/
private static final char OTHER_SEPARATOR;
static {
if (SYSTEM_SEPARATOR == WINDOWS_SEPARATOR) {
OTHER_SEPARATOR = UNIX_SEPARATOR;
} else {
OTHER_SEPARATOR = WINDOWS_SEPARATOR;
}
}
/**
* Checks if the character is a separator.
*/
private static boolean isSeparator(final char ch) {
return (ch == UNIX_SEPARATOR) || (ch == WINDOWS_SEPARATOR);
}
// ---------------------------------------------------------------- normalization
public static String normalize(final String filename) {
return doNormalize(filename, SYSTEM_SEPARATOR, true);
}
/**
* Normalizes a path, removing double and single dot path steps.
*
* This method normalizes a path to a standard format.
* The input may contain separators in either Unix or Windows format.
* The output will contain separators in the format of the system.
*
* A trailing slash will be retained.
* A double slash will be merged to a single slash (but UNC names are handled).
* A single dot path segment will be removed.
* A double dot will cause that path segment and the one before to be removed.
* If the double dot has no parent path segment to work with, null
* is returned.
*
* The output will be the same on both Unix and Windows except
* for the separator character.
*
{@code
* /foo// --> /foo/
* /foo/./ --> /foo/
* /foo/../bar --> /bar
* /foo/../bar/ --> /bar/
* /foo/../bar/../baz --> /baz
* //foo//./bar --> /foo/bar
* /../ --> null
* ../foo --> null
* foo/bar/.. --> foo/
* foo/../../bar --> null
* foo/../bar --> bar
* //server/foo/../bar --> //server/bar
* //server/../bar --> null
* C:\foo\..\bar --> C:\bar
* C:\..\bar --> null
* ~/foo/../bar/ --> ~/bar/
* ~/../bar --> null
* }
* (Note the file separator returned will be correct for Windows/Unix)
*
* @param filename the filename to normalize, null returns null
* @return the normalized filename, or null if invalid
*/
public static String normalize(final String filename, final boolean unixSeparator) {
char separator = (unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR);
return doNormalize(filename, separator, true);
}
public static String normalizeNoEndSeparator(final String filename) {
return doNormalize(filename, SYSTEM_SEPARATOR, false);
}
/**
* Normalizes a path, removing double and single dot path steps,
* and removing any final directory separator.
*
* This method normalizes a path to a standard format.
* The input may contain separators in either Unix or Windows format.
* The output will contain separators in the format of the system.
*
* A trailing slash will be removed.
* A double slash will be merged to a single slash (but UNC names are handled).
* A single dot path segment will be removed.
* A double dot will cause that path segment and the one before to be removed.
* If the double dot has no parent path segment to work with, null
* is returned.
*
* The output will be the same on both Unix and Windows except
* for the separator character.
*
{@code
* /foo// --> /foo
* /foo/./ --> /foo
* /foo/../bar --> /bar
* /foo/../bar/ --> /bar
* /foo/../bar/../baz --> /baz
* /foo//./bar --> /foo/bar
* /../ --> null
* ../foo --> null
* foo/bar/.. --> foo
* foo/../../bar --> null
* foo/../bar --> bar
* //server/foo/../bar --> //server/bar
* //server/../bar --> null
* C:\foo\..\bar --> C:\bar
* C:\..\bar --> null
* ~/foo/../bar/ --> ~/bar
* ~/../bar --> null
* }
* (Note the file separator returned will be correct for Windows/Unix)
*
* @param filename the filename to normalize, null returns null
* @return the normalized filename, or null if invalid
*/
public static String normalizeNoEndSeparator(final String filename, final boolean unixSeparator) {
char separator = (unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR);
return doNormalize(filename, separator, false);
}
/**
* Internal method to perform the normalization.
*
* @param filename file name
* @param separator separator character to use
* @param keepSeparator true to keep the final separator
* @return normalized filename
*/
private static String doNormalize(final String filename, final char separator, final boolean keepSeparator) {
if (filename == null) {
return null;
}
int size = filename.length();
if (size == 0) {
return filename;
}
int prefix = getPrefixLength(filename);
if (prefix < 0) {
return null;
}
char[] array = new char[size + 2]; // +1 for possible extra slash, +2 for arraycopy
filename.getChars(0, filename.length(), array, 0);
// fix separators throughout
char otherSeparator = (separator == SYSTEM_SEPARATOR ? OTHER_SEPARATOR : SYSTEM_SEPARATOR);
for (int i = 0; i < array.length; i++) {
if (array[i] == otherSeparator) {
array[i] = separator;
}
}
// add extra separator on the end to simplify code below
boolean lastIsDirectory = true;
if (array[size - 1] != separator) {
array[size++] = separator;
lastIsDirectory = false;
}
// adjoining slashes
for (int i = prefix + 1; i < size; i++) {
if (array[i] == separator && array[i - 1] == separator) {
System.arraycopy(array, i, array, i - 1, size - i);
size--;
i--;
}
}
// dot slash
for (int i = prefix + 1; i < size; i++) {
if (array[i] == separator && array[i - 1] == '.' &&
(i == prefix + 1 || array[i - 2] == separator)) {
if (i == size - 1) {
lastIsDirectory = true;
}
System.arraycopy(array, i + 1, array, i - 1, size - i);
size -= 2;
i--;
}
}
// double dot slash
outer:
for (int i = prefix + 2; i < size; i++) {
if (array[i] == separator && array[i - 1] == '.' && array[i - 2] == '.' &&
(i == prefix + 2 || array[i - 3] == separator)) {
if (i == prefix + 2) {
return null;
}
if (i == size - 1) {
lastIsDirectory = true;
}
int j;
for (j = i - 4 ; j >= prefix; j--) {
if (array[j] == separator) {
// remove b/../ from a/b/../c
System.arraycopy(array, i + 1, array, j + 1, size - i);
size -= (i - j);
i = j + 1;
continue outer;
}
}
// remove a/../ from a/../c
System.arraycopy(array, i + 1, array, prefix, size - i);
size -= (i + 1 - prefix);
i = prefix + 1;
}
}
if (size <= 0) { // should never be less than 0
return StringPool.EMPTY;
}
if (size <= prefix) { // should never be less than prefix
return new String(array, 0, size);
}
if (lastIsDirectory && keepSeparator) {
return new String(array, 0, size); // keep trailing separator
}
return new String(array, 0, size - 1); // lose trailing separator
}
//-----------------------------------------------------------------------
/**
* Concatenates a filename to a base path using normal command line style rules.
*
* The effect is equivalent to resultant directory after changing
* directory to the first argument, followed by changing directory to
* the second argument.
*
* The first argument is the base path, the second is the path to concatenate.
* The returned path is always normalized via {@link #normalize(String)},
* thus .. is handled.
*
* If pathToAdd is absolute (has an absolute prefix), then
* it will be normalized and returned.
* Otherwise, the paths will be joined, normalized and returned.
*
* The output will be the same on both Unix and Windows except
* for the separator character.
*
{@code
* /foo/ + bar --> /foo/bar
* /foo + bar --> /foo/bar
* /foo + /bar --> /bar
* /foo + C:/bar --> C:/bar
* /foo + C:bar --> C:bar (*)
* /foo/a/ + ../bar --> foo/bar
* /foo/ + ../../bar --> null
* /foo/ + /bar --> /bar
* /foo/.. + /bar --> /bar
* /foo + bar/c.txt --> /foo/bar/c.txt
* /foo/c.txt + bar --> /foo/c.txt/bar (!)
* }
* (*) Note that the Windows relative drive prefix is unreliable when
* used with this method.
* (!) Note that the first parameter must be a path. If it ends with a name, then
* the name will be built into the concatenated path. If this might be a problem,
* use {@link #getFullPath(String)} on the base path argument.
*
* @param basePath the base path to attach to, always treated as a path
* @param fullFilenameToAdd the filename (or path) to attach to the base
* @return the concatenated path, or null if invalid
*/
public static String concat(final String basePath, final String fullFilenameToAdd) {
return doConcat(basePath, fullFilenameToAdd, SYSTEM_SEPARATOR);
}
public static String concat(final String basePath, final String fullFilenameToAdd, final boolean unixSeparator) {
char separator = (unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR);
return doConcat(basePath, fullFilenameToAdd, separator);
}
public static String doConcat(final String basePath, final String fullFilenameToAdd, final char separator) {
int prefix = getPrefixLength(fullFilenameToAdd);
if (prefix < 0) {
return null;
}
if (prefix > 0) {
return doNormalize(fullFilenameToAdd, separator, true);
}
if (basePath == null) {
return null;
}
int len = basePath.length();
if (len == 0) {
return doNormalize(fullFilenameToAdd, separator, true);
}
char ch = basePath.charAt(len - 1);
if (isSeparator(ch)) {
return doNormalize(basePath + fullFilenameToAdd, separator, true);
} else {
return doNormalize(basePath + '/' + fullFilenameToAdd, separator, true);
}
}
// ---------------------------------------------------------------- separator conversion
/**
* Converts all separators to the Unix separator of forward slash.
*
* @param path the path to be changed, null ignored
* @return the updated path
*/
public static String separatorsToUnix(final String path) {
if (path == null || path.indexOf(WINDOWS_SEPARATOR) == -1) {
return path;
}
return path.replace(WINDOWS_SEPARATOR, UNIX_SEPARATOR);
}
/**
* Converts all separators to the Windows separator of backslash.
*
* @param path the path to be changed, null ignored
* @return the updated path
*/
public static String separatorsToWindows(final String path) {
if (path == null || path.indexOf(UNIX_SEPARATOR) == -1) {
return path;
}
return path.replace(UNIX_SEPARATOR, WINDOWS_SEPARATOR);
}
/**
* Converts all separators to the system separator.
*
* @param path the path to be changed, null ignored
* @return the updated path
*/
public static String separatorsToSystem(final String path) {
if (path == null) {
return null;
}
if (SYSTEM_SEPARATOR == WINDOWS_SEPARATOR) {
return separatorsToWindows(path);
} else {
return separatorsToUnix(path);
}
}
// ---------------------------------------------------------------- prefix
/**
* Returns the length of the filename prefix, such as C:/ or ~/.
*
* This method will handle a file in either Unix or Windows format.
*
* The prefix length includes the first slash in the full filename
* if applicable. Thus, it is possible that the length returned is greater
* than the length of the input string.
*
{@code
* Windows:
* a\b\c.txt --> "" --> relative
* \a\b\c.txt --> "\" --> current drive absolute
* C:a\b\c.txt --> "C:" --> drive relative
* C:\a\b\c.txt --> "C:\" --> absolute
* \\server\a\b\c.txt --> "\\server\" --> UNC
*
* Unix:
* a/b/c.txt --> "" --> relative
* /a/b/c.txt --> "/" --> absolute
* ~/a/b/c.txt --> "~/" --> current user
* ~ --> "~/" --> current user (slash added)
* ~user/a/b/c.txt --> "~user/" --> named user
* ~user --> "~user/" --> named user (slash added)
* }
*
* The output will be the same irrespective of the machine that the code is running on.
* ie. both Unix and Windows prefixes are matched regardless.
*
* @param filename the filename to find the prefix in, null returns -1
* @return the length of the prefix, -1 if invalid or null
*/
public static int getPrefixLength(final String filename) {
if (filename == null) {
return -1;
}
int len = filename.length();
if (len == 0) {
return 0;
}
char ch0 = filename.charAt(0);
if (ch0 == ':') {
return -1;
}
if (len == 1) {
if (ch0 == '~') {
return 2; // return a length greater than the input
}
return (isSeparator(ch0) ? 1 : 0);
} else {
if (ch0 == '~') {
int posUnix = filename.indexOf(UNIX_SEPARATOR, 1);
int posWin = filename.indexOf(WINDOWS_SEPARATOR, 1);
if (posUnix == -1 && posWin == -1) {
return len + 1; // return a length greater than the input
}
posUnix = (posUnix == -1 ? posWin : posUnix);
posWin = (posWin == -1 ? posUnix : posWin);
return Math.min(posUnix, posWin) + 1;
}
char ch1 = filename.charAt(1);
if (ch1 == ':') {
ch0 = Character.toUpperCase(ch0);
if (ch0 >= 'A' && ch0 <= 'Z') {
if (len == 2 || !isSeparator(filename.charAt(2))) {
return 2;
}
return 3;
}
return -1;
} else if (isSeparator(ch0) && isSeparator(ch1)) {
int posUnix = filename.indexOf(UNIX_SEPARATOR, 2);
int posWin = filename.indexOf(WINDOWS_SEPARATOR, 2);
if ((posUnix == -1 && posWin == -1) || posUnix == 2 || posWin == 2) {
return -1;
}
posUnix = (posUnix == -1 ? posWin : posUnix);
posWin = (posWin == -1 ? posUnix : posWin);
return Math.min(posUnix, posWin) + 1;
} else {
return (isSeparator(ch0) ? 1 : 0);
}
}
}
/**
* Returns the index of the last directory separator character.
*
* This method will handle a file in either Unix or Windows format.
* The position of the last forward or backslash is returned.
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to find the last path separator in, null returns -1
* @return the index of the last separator character, or -1 if there is no such character
*/
public static int indexOfLastSeparator(final String filename) {
if (filename == null) {
return -1;
}
int lastUnixPos = filename.lastIndexOf(UNIX_SEPARATOR);
int lastWindowsPos = filename.lastIndexOf(WINDOWS_SEPARATOR);
return Math.max(lastUnixPos, lastWindowsPos);
}
/**
* Returns the index of the last extension separator character, which is a dot.
*
* This method also checks that there is no directory separator after the last dot.
* To do this it uses {@link #indexOfLastSeparator(String)} which will
* handle a file in either Unix or Windows format.
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to find the last path separator in, null returns -1
* @return the index of the last separator character, or -1 if there
* is no such character
*/
public static int indexOfExtension(final String filename) {
if (filename == null) {
return -1;
}
int extensionPos = filename.lastIndexOf(EXTENSION_SEPARATOR);
int lastSeparator = indexOfLastSeparator(filename);
return (lastSeparator > extensionPos ? -1 : extensionPos);
}
/**
* Returns true if file has extension.
*/
public static boolean hasExtension(final String filename) {
return indexOfExtension(filename) != -1;
}
// ---------------------------------------------------------------- get
/**
* Gets the prefix from a full filename, such as C:/
* or ~/.
*
* This method will handle a file in either Unix or Windows format.
* The prefix includes the first slash in the full filename where applicable.
*
{@code
* Windows:
* a\b\c.txt --> "" --> relative
* \a\b\c.txt --> "\" --> current drive absolute
* C:a\b\c.txt --> "C:" --> drive relative
* C:\a\b\c.txt --> "C:\" --> absolute
* \\server\a\b\c.txt --> "\\server\" --> UNC
*
* Unix:
* a/b/c.txt --> "" --> relative
* /a/b/c.txt --> "/" --> absolute
* ~/a/b/c.txt --> "~/" --> current user
* ~ --> "~/" --> current user (slash added)
* ~user/a/b/c.txt --> "~user/" --> named user
* ~user --> "~user/" --> named user (slash added)
* }
*
* The output will be the same irrespective of the machine that the code is running on.
* ie. both Unix and Windows prefixes are matched regardless.
*
* @param filename the filename to query, null returns null
* @return the prefix of the file, null if invalid
*/
public static String getPrefix(final String filename) {
if (filename == null) {
return null;
}
int len = getPrefixLength(filename);
if (len < 0) {
return null;
}
if (len > filename.length()) {
return filename + UNIX_SEPARATOR; // we know this only happens for unix
}
return filename.substring(0, len);
}
/**
* Gets the path from a full filename, which excludes the prefix.
*
* This method will handle a file in either Unix or Windows format.
* The method is entirely text based, and returns the text before and
* including the last forward or backslash.
*
{@code
* C:\a\b\c.txt --> a\b\
* ~/a/b/c.txt --> a/b/
* a.txt --> ""
* a/b/c --> a/b/
* a/b/c/ --> a/b/c/
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* This method drops the prefix from the result.
* See {@link #getFullPath(String)} for the method that retains the prefix.
*
* @param filename the filename to query, null returns null
* @return the path of the file, an empty string if none exists, null if invalid
*/
public static String getPath(final String filename) {
return doGetPath(filename, 1);
}
/**
* Gets the path from a full filename, which excludes the prefix, and
* also excluding the final directory separator.
*
* This method will handle a file in either Unix or Windows format.
* The method is entirely text based, and returns the text before the
* last forward or backslash.
*
{@code
* C:\a\b\c.txt --> a\b
* ~/a/b/c.txt --> a/b
* a.txt --> ""
* a/b/c --> a/b
* a/b/c/ --> a/b/c
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* This method drops the prefix from the result.
* See {@link #getFullPathNoEndSeparator(String)} for the method that retains the prefix.
*
* @param filename the filename to query, null returns null
* @return the path of the file, an empty string if none exists, null if invalid
*/
public static String getPathNoEndSeparator(final String filename) {
return doGetPath(filename, 0);
}
/**
* Does the work of getting the path.
*
* @param filename the filename
* @param separatorAdd 0 to omit the end separator, 1 to return it
* @return the path
*/
private static String doGetPath(final String filename, final int separatorAdd) {
if (filename == null) {
return null;
}
int prefix = getPrefixLength(filename);
if (prefix < 0) {
return null;
}
int index = indexOfLastSeparator(filename);
int endIndex = index + separatorAdd;
if (prefix >= filename.length() || index < 0 || prefix >= endIndex) {
return StringPool.EMPTY;
}
return filename.substring(prefix, endIndex);
}
/**
* Gets the full path from a full filename, which is the prefix + path.
*
* This method will handle a file in either Unix or Windows format.
* The method is entirely text based, and returns the text before and
* including the last forward or backslash.
*
{@code
* C:\a\b\c.txt --> C:\a\b\
* ~/a/b/c.txt --> ~/a/b/
* a.txt --> ""
* a/b/c --> a/b/
* a/b/c/ --> a/b/c/
* C: --> C:
* C:\ --> C:\
* ~ --> ~/
* ~/ --> ~/
* ~user --> ~user/
* ~user/ --> ~user/
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to query, null returns null
* @return the path of the file, an empty string if none exists, null if invalid
*/
public static String getFullPath(final String filename) {
return doGetFullPath(filename, true);
}
/**
* Gets the full path from a full filename, which is the prefix + path,
* and also excluding the final directory separator.
*
* This method will handle a file in either Unix or Windows format.
* The method is entirely text based, and returns the text before the
* last forward or backslash.
*
{@code
* C:\a\b\c.txt --> C:\a\b
* ~/a/b/c.txt --> ~/a/b
* a.txt --> ""
* a/b/c --> a/b
* a/b/c/ --> a/b/c
* C: --> C:
* C:\ --> C:\
* ~ --> ~
* ~/ --> ~
* ~user --> ~user
* ~user/ --> ~user
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to query, null returns null
* @return the path of the file, an empty string if none exists, null if invalid
*/
public static String getFullPathNoEndSeparator(final String filename) {
return doGetFullPath(filename, false);
}
/**
* Does the work of getting the path.
*
* @param filename the filename
* @param includeSeparator true to include the end separator
* @return the path
*/
private static String doGetFullPath(final String filename, final boolean includeSeparator) {
if (filename == null) {
return null;
}
int prefix = getPrefixLength(filename);
if (prefix < 0) {
return null;
}
if (prefix >= filename.length()) {
if (includeSeparator) {
return getPrefix(filename); // add end slash if necessary
} else {
return filename;
}
}
int index = indexOfLastSeparator(filename);
if (index < 0) {
return filename.substring(0, prefix);
}
int end = index + (includeSeparator ? 1 : 0);
if (end == 0) {
end++;
}
return filename.substring(0, end);
}
/**
* Gets the name minus the path from a full filename.
*
* This method will handle a file in either Unix or Windows format.
* The text after the last forward or backslash is returned.
*
{@code
* a/b/c.txt --> c.txt
* a.txt --> a.txt
* a/b/c --> c
* a/b/c/ --> ""
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to query, null returns null
* @return the name of the file without the path, or an empty string if none exists
*/
public static String getName(final String filename) {
if (filename == null) {
return null;
}
int index = indexOfLastSeparator(filename);
return filename.substring(index + 1);
}
/**
* Gets the base name, minus the full path and extension, from a full filename.
*
* This method will handle a file in either Unix or Windows format.
* The text after the last forward or backslash and before the last dot is returned.
*
{@code
* a/b/c.txt --> c
* a.txt --> a
* a/b/c --> c
* a/b/c/ --> ""
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to query, null returns null
* @return the name of the file without the path, or an empty string if none exists
*/
public static String getBaseName(final String filename) {
return removeExtension(getName(filename));
}
/**
* Gets the extension of a filename.
*
* This method returns the textual part of the filename after the last dot.
* There must be no directory separator after the dot.
*
{@code
* foo.txt --> "txt"
* a/b/c.jpg --> "jpg"
* a/b.txt/c --> ""
* a/b/c --> ""
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to retrieve the extension of.
* @return the extension of the file or an empty string if none exists.
*/
public static String getExtension(final String filename) {
if (filename == null) {
return null;
}
int index = indexOfExtension(filename);
if (index == -1) {
return StringPool.EMPTY;
} else {
return filename.substring(index + 1);
}
}
//----------------------------------------------------------------------- remove
/**
* Removes the extension from a filename.
*
* This method returns the textual part of the filename before the last dot.
* There must be no directory separator after the dot.
*
{@code
* foo.txt --> foo
* a\b\c.jpg --> a\b\c
* a\b\c --> a\b\c
* a.b\c --> a.b\c
* }
*
* The output will be the same irrespective of the machine that the code is running on.
*
* @param filename the filename to query, null returns null
* @return the filename minus the extension
*/
public static String removeExtension(final String filename) {
if (filename == null) {
return null;
}
int index = indexOfExtension(filename);
if (index == -1) {
return filename;
} else {
return filename.substring(0, index);
}
}
// ---------------------------------------------------------------- equals
/**
* Checks whether two filenames are equal exactly.
*/
public static boolean equals(final String filename1, final String filename2) {
return equals(filename1, filename2, false);
}
/**
* Checks whether two filenames are equal using the case rules of the system.
*/
public static boolean equalsOnSystem(final String filename1, final String filename2) {
return equals(filename1, filename2, true);
}
/**
* Checks whether two filenames are equal optionally using the case rules of the system.
*
*
* @param filename1 the first filename to query, may be null
* @param filename2 the second filename to query, may be null
* @param system whether to use the system (windows or unix)
* @return true if the filenames are equal, null equals null
*/
private static boolean equals(final String filename1, final String filename2, final boolean system) {
//noinspection StringEquality
if (filename1 == filename2) {
return true;
}
if (filename1 == null || filename2 == null) {
return false;
}
if (system && (SYSTEM_SEPARATOR == WINDOWS_SEPARATOR)) {
return filename1.equalsIgnoreCase(filename2);
} else {
return filename1.equals(filename2);
}
}
// ---------------------------------------------------------------- split
/**
* Splits filename into a array of four Strings containing prefix, path, basename and extension.
* Path will contain ending separator.
*/
public static String[] split(final String filename) {
String prefix = getPrefix(filename);
if (prefix == null) {
prefix = StringPool.EMPTY;
}
int lastSeparatorIndex = indexOfLastSeparator(filename);
int lastExtensionIndex = indexOfExtension(filename);
String path;
String baseName;
String extension;
if (lastSeparatorIndex == -1) {
path = StringPool.EMPTY;
if (lastExtensionIndex == -1) {
baseName = filename.substring(prefix.length());
extension = StringPool.EMPTY;
} else {
baseName = filename.substring(prefix.length(), lastExtensionIndex);
extension = filename.substring(lastExtensionIndex + 1);
}
} else {
path = filename.substring(prefix.length(), lastSeparatorIndex + 1);
if (lastExtensionIndex == -1) {
baseName = filename.substring(prefix.length() + path.length());
extension = StringPool.EMPTY;
} else {
baseName = filename.substring(prefix.length() + path.length(), lastExtensionIndex);
extension = filename.substring(lastExtensionIndex + 1);
}
}
return new String[] {prefix, path, baseName, extension};
}
// ---------------------------------------------------------------- home
/**
* Resolve ~ in the path.
*/
public static String resolveHome(final String path) {
if (path.length() == 1) {
if (path.charAt(0) == '~') {
return SystemUtil.info().getHomeDir();
}
return path;
}
if (path.length() >= 2) {
if ((path.charAt(0) == '~') && (path.charAt(1) == File.separatorChar)) {
return SystemUtil.info().getHomeDir() + path.substring(1);
}
}
return path;
}
/**
* Calculates relative path of target path on base path.
*/
public static String relativePath(final String targetPath, final String basePath) {
return new File(basePath).toPath().relativize(new File(targetPath).toPath()).toString();
}
}