Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.io; import java.io.File; import java.util.ArrayList; import java.util.Collection; import java.util.Stack; /** * General filename and filepath manipulation utilities. * <p> * 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. * <p> * <b>NOTE</b>: 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)}. * <p> * 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. * <p> * Most methods recognise both separators (forward and back), and both * sets of prefixes. See the javadoc of each method for details. * <p> * This class defines six components within a filename * (example C:\dev\project\file.txt): * <ul> * <li>the prefix - C:\</li> * <li>the path - dev\project\</li> * <li>the full path - C:\dev\project\</li> * <li>the name - file.txt</li> * <li>the base name - file</li> * <li>the extension - txt</li> * </ul> * 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. * <p> * This class only supports Unix and Windows style names. * Prefixes are matched as follows: * <pre> * 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) * </pre> * Both prefix styles are matched always, irrespective of the machine that you are * currently running on. * <p> * Origin of code: Excalibur, Alexandria, Tomcat, Commons-Utils. * * @author <a href="mailto:burton@relativity.yi.org">Kevin A. Burton</A> * @author <a href="mailto:sanders@apache.org">Scott Sanders</a> * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> * @author <a href="mailto:Christoph.Reck@dlr.de">Christoph.Reck</a> * @author <a href="mailto:peter@apache.org">Peter Donald</a> * @author <a href="mailto:jefft@apache.org">Jeff Turner</a> * @author Matthew Hawthorne * @author Martin Cooper * @author <a href="mailto:jeremias@apache.org">Jeremias Maerki</a> * @author Stephen Colebourne * @version $Id: FilenameUtils.java 1004077 2010-10-04 00:58:42Z niallp $ * @since Commons IO 1.1 */ public class FilenameUtils { /** * The extension separator character. * @since Commons IO 1.4 */ public static final char EXTENSION_SEPARATOR = '.'; /** * The extension separator String. * @since Commons IO 1.4 */ public static final String EXTENSION_SEPARATOR_STR = Character.toString(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 (isSystemWindows()) { OTHER_SEPARATOR = UNIX_SEPARATOR; } else { OTHER_SEPARATOR = WINDOWS_SEPARATOR; } } /** * Instances should NOT be constructed in standard programming. */ public FilenameUtils() { super(); } //----------------------------------------------------------------------- /** * Determines if Windows file system is in use. * * @return true if the system is Windows */ static boolean isSystemWindows() { return SYSTEM_SEPARATOR == WINDOWS_SEPARATOR; } //----------------------------------------------------------------------- /** * Checks if the character is a separator. * * @param ch the character to check * @return true if it is a separator character */ private static boolean isSeparator(char ch) { return (ch == UNIX_SEPARATOR) || (ch == WINDOWS_SEPARATOR); } //----------------------------------------------------------------------- /** * Normalizes a path, removing double and single dot path steps. * <p> * 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. * <p> * 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, <code>null</code> * is returned. * <p> * The output will be the same on both Unix and Windows except * for the separator character. * <pre> * /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 * </pre> * (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(String filename) { return doNormalize(filename, SYSTEM_SEPARATOR, true); } /** * Normalizes a path, removing double and single dot path steps. * <p> * 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 specified. * <p> * 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, <code>null</code> * is returned. * <p> * The output will be the same on both Unix and Windows except * for the separator character. * <pre> * /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 * </pre> * The output will be the same on both Unix and Windows including * the separator character. * * @param filename the filename to normalize, null returns null * @param unixSeparator <code>true</code> if a unix separator should * be used or <code>false</code> if a windows separator should be used. * @return the normalized filename, or null if invalid * @since Commons IO 2.0 */ public static String normalize(String filename, boolean unixSeparator) { char separator = (unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR); return doNormalize(filename, separator, true); } //----------------------------------------------------------------------- /** * Normalizes a path, removing double and single dot path steps, * and removing any final directory separator. * <p> * 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. * <p> * 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, <code>null</code> * is returned. * <p> * The output will be the same on both Unix and Windows except * for the separator character. * <pre> * /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 * </pre> * (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(String filename) { return doNormalize(filename, SYSTEM_SEPARATOR, false); } /** * Normalizes a path, removing double and single dot path steps, * and removing any final directory separator. * <p> * 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 specified. * <p> * 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, <code>null</code> * is returned. * <p> * The output will be the same on both Unix and Windows including * the separator character. * <pre> * /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 * </pre> * * @param filename the filename to normalize, null returns null * @param unixSeparator <code>true</code> if a unix separator should * be used or <code>false</code> if a windows separtor should be used. * @return the normalized filename, or null if invalid * @since Commons IO 2.0 */ public static String normalizeNoEndSeparator(String filename, boolean unixSeparator) { char separator = (unixSeparator ? UNIX_SEPARATOR : WINDOWS_SEPARATOR); return doNormalize(filename, separator, false); } /** * Internal method to perform the normalization. * * @param filename the filename * @param separator The separator character to use * @param keepSeparator true to keep the final separator * @return the normalized filename */ private static String doNormalize(String filename, char separator, 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 ""; } 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. * <p> * The effect is equivalent to resultant directory after changing * directory to the first argument, followed by changing directory to * the second argument. * <p> * 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 <code>..</code> is handled. * <p> * If <code>pathToAdd</code> is absolute (has an absolute prefix), then * it will be normalized and returned. * Otherwise, the paths will be joined, normalized and returned. * <p> * The output will be the same on both Unix and Windows except * for the separator character. * <pre> * /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 (!) * </pre> * (*) 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(String basePath, String fullFilenameToAdd) { int prefix = getPrefixLength(fullFilenameToAdd); if (prefix < 0) { return null; } if (prefix > 0) { return normalize(fullFilenameToAdd); } if (basePath == null) { return null; } int len = basePath.length(); if (len == 0) { return normalize(fullFilenameToAdd); } char ch = basePath.charAt(len - 1); if (isSeparator(ch)) { return normalize(basePath + fullFilenameToAdd); } else { return normalize(basePath + '/' + fullFilenameToAdd); } } //----------------------------------------------------------------------- /** * 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(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(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(String path) { if (path == null) { return null; } if (isSystemWindows()) { return separatorsToWindows(path); } else { return separatorsToUnix(path); } } //----------------------------------------------------------------------- /** * Returns the length of the filename prefix, such as <code>C:/</code> or <code>~/</code>. * <p> * This method will handle a file in either Unix or Windows format. * <p> * 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. * <pre> * 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) * </pre> * <p> * 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(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)) == false) { 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. * <p> * This method will handle a file in either Unix or Windows format. * The position of the last forward or backslash is returned. * <p> * 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(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. * <p> * 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. * <p> * 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(String filename) { if (filename == null) { return -1; } int extensionPos = filename.lastIndexOf(EXTENSION_SEPARATOR); int lastSeparator = indexOfLastSeparator(filename); return (lastSeparator > extensionPos ? -1 : extensionPos); } //----------------------------------------------------------------------- /** * Gets the prefix from a full filename, such as <code>C:/</code> * or <code>~/</code>. * <p> * This method will handle a file in either Unix or Windows format. * The prefix includes the first slash in the full filename where applicable. * <pre> * 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) * </pre> * <p> * 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(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. * <p> * 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. * <pre> * 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/ * </pre> * <p> * The output will be the same irrespective of the machine that the code is running on. * <p> * 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(String filename) { return doGetPath(filename, 1); } /** * Gets the path from a full filename, which excludes the prefix, and * also excluding the final directory separator. * <p> * 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. * <pre> * 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 * </pre> * <p> * The output will be the same irrespective of the machine that the code is running on. * <p> * 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(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(String filename, 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 ""; } return filename.substring(prefix, endIndex); } /** * Gets the full path from a full filename, which is the prefix + path. * <p> * 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. * <pre> * 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/ * </pre> * <p> * 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(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. * <p> * 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. * <pre> * 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 * </pre> * <p> * 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(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(String filename, 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. * <p> * This method will handle a file in either Unix or Windows format. * The text after the last forward or backslash is returned. * <pre> * a/b/c.txt --> c.txt * a.txt --> a.txt * a/b/c --> c * a/b/c/ --> "" * </pre> * <p> * 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(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. * <p> * 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. * <pre> * a/b/c.txt --> c * a.txt --> a * a/b/c --> c * a/b/c/ --> "" * </pre> * <p> * 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(String filename) { return removeExtension(getName(filename)); } /** * Gets the extension of a filename. * <p> * This method returns the textual part of the filename after the last dot. * There must be no directory separator after the dot. * <pre> * foo.txt --> "txt" * a/b/c.jpg --> "jpg" * a/b.txt/c --> "" * a/b/c --> "" * </pre> * <p> * 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 or <code>null</code> * if the filename is <code>null</code>. */ public static String getExtension(String filename) { if (filename == null) { return null; } int index = indexOfExtension(filename); if (index == -1) { return ""; } else { return filename.substring(index + 1); } } //----------------------------------------------------------------------- /** * Removes the extension from a filename. * <p> * This method returns the textual part of the filename before the last dot. * There must be no directory separator after the dot. * <pre> * foo.txt --> foo * a\b\c.jpg --> a\b\c * a\b\c --> a\b\c * a.b\c --> a.b\c * </pre> * <p> * 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(String filename) { if (filename == null) { return null; } int index = indexOfExtension(filename); if (index == -1) { return filename; } else { return filename.substring(0, index); } } //----------------------------------------------------------------------- /** * Checks whether two filenames are equal exactly. * <p> * No processing is performed on the filenames other than comparison, * thus this is merely a null-safe case-sensitive equals. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SENSITIVE */ public static boolean equals(String filename1, String filename2) { return equals(filename1, filename2, false, IOCase.SENSITIVE); } /** * Checks whether two filenames are equal using the case rules of the system. * <p> * No processing is performed on the filenames other than comparison. * The check is case-sensitive on Unix and case-insensitive on Windows. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SYSTEM */ public static boolean equalsOnSystem(String filename1, String filename2) { return equals(filename1, filename2, false, IOCase.SYSTEM); } //----------------------------------------------------------------------- /** * Checks whether two filenames are equal after both have been normalized. * <p> * Both filenames are first passed to {@link #normalize(String)}. * The check is then performed in a case-sensitive manner. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SENSITIVE */ public static boolean equalsNormalized(String filename1, String filename2) { return equals(filename1, filename2, true, IOCase.SENSITIVE); } /** * Checks whether two filenames are equal after both have been normalized * and using the case rules of the system. * <p> * Both filenames are first passed to {@link #normalize(String)}. * The check is then performed case-sensitive on Unix and * case-insensitive on Windows. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @return true if the filenames are equal, null equals null * @see IOCase#SYSTEM */ public static boolean equalsNormalizedOnSystem(String filename1, String filename2) { return equals(filename1, filename2, true, IOCase.SYSTEM); } /** * Checks whether two filenames are equal, optionally normalizing and providing * control over the case-sensitivity. * * @param filename1 the first filename to query, may be null * @param filename2 the second filename to query, may be null * @param normalized whether to normalize the filenames * @param caseSensitivity what case sensitivity rule to use, null means case-sensitive * @return true if the filenames are equal, null equals null * @since Commons IO 1.3 */ public static boolean equals(String filename1, String filename2, boolean normalized, IOCase caseSensitivity) { if (filename1 == null || filename2 == null) { return (filename1 == null && filename2 == null); } if (normalized) { filename1 = normalize(filename1); filename2 = normalize(filename2); if (filename1 == null || filename2 == null) { throw new NullPointerException("Error normalizing one or both of the file names"); } } if (caseSensitivity == null) { caseSensitivity = IOCase.SENSITIVE; } return caseSensitivity.checkEquals(filename1, filename2); } //----------------------------------------------------------------------- /** * Checks whether the extension of the filename is that specified. * <p> * This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extension the extension to check for, null or empty checks for no extension * @return true if the filename has the specified extension */ public static boolean isExtension(String filename, String extension) { if (filename == null) { return false; } if (extension == null || extension.length() == 0) { return (indexOfExtension(filename) == -1); } String fileExt = getExtension(filename); return fileExt.equals(extension); } /** * Checks whether the extension of the filename is one of those specified. * <p> * This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extensions the extensions to check for, null checks for no extension * @return true if the filename is one of the extensions */ public static boolean isExtension(String filename, String[] extensions) { if (filename == null) { return false; } if (extensions == null || extensions.length == 0) { return (indexOfExtension(filename) == -1); } String fileExt = getExtension(filename); for (String extension : extensions) { if (fileExt.equals(extension)) { return true; } } return false; } /** * Checks whether the extension of the filename is one of those specified. * <p> * This method obtains the extension as the textual part of the filename * after the last dot. There must be no directory separator after the dot. * The extension check is case-sensitive on all platforms. * * @param filename the filename to query, null returns false * @param extensions the extensions to check for, null checks for no extension * @return true if the filename is one of the extensions */ public static boolean isExtension(String filename, Collection<String> extensions) { if (filename == null) { return false; } if (extensions == null || extensions.isEmpty()) { return (indexOfExtension(filename) == -1); } String fileExt = getExtension(filename); for (String extension : extensions) { if (fileExt.equals(extension)) { return true; } } return false; } //----------------------------------------------------------------------- /** * Checks a filename to see if it matches the specified wildcard matcher, * always testing case-sensitive. * <p> * The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * This is the same as often found on Dos/Unix command lines. * The check is case-sensitive always. * <pre> * wildcardMatch("c.txt", "*.txt") --> true * wildcardMatch("c.txt", "*.jpg") --> false * wildcardMatch("a/b/c.txt", "a/b/*") --> true * wildcardMatch("c.txt", "*.???") --> true * wildcardMatch("c.txt", "*.????") --> false * </pre> * N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @return true if the filename matches the wilcard string * @see IOCase#SENSITIVE */ public static boolean wildcardMatch(String filename, String wildcardMatcher) { return wildcardMatch(filename, wildcardMatcher, IOCase.SENSITIVE); } /** * Checks a filename to see if it matches the specified wildcard matcher * using the case rules of the system. * <p> * The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * This is the same as often found on Dos/Unix command lines. * The check is case-sensitive on Unix and case-insensitive on Windows. * <pre> * wildcardMatch("c.txt", "*.txt") --> true * wildcardMatch("c.txt", "*.jpg") --> false * wildcardMatch("a/b/c.txt", "a/b/*") --> true * wildcardMatch("c.txt", "*.???") --> true * wildcardMatch("c.txt", "*.????") --> false * </pre> * N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @return true if the filename matches the wilcard string * @see IOCase#SYSTEM */ public static boolean wildcardMatchOnSystem(String filename, String wildcardMatcher) { return wildcardMatch(filename, wildcardMatcher, IOCase.SYSTEM); } /** * Checks a filename to see if it matches the specified wildcard matcher * allowing control over case-sensitivity. * <p> * The wildcard matcher uses the characters '?' and '*' to represent a * single or multiple (zero or more) wildcard characters. * N.B. the sequence "*?" does not work properly at present in match strings. * * @param filename the filename to match on * @param wildcardMatcher the wildcard string to match against * @param caseSensitivity what case sensitivity rule to use, null means case-sensitive * @return true if the filename matches the wilcard string * @since Commons IO 1.3 */ public static boolean wildcardMatch(String filename, String wildcardMatcher, IOCase caseSensitivity) { if (filename == null && wildcardMatcher == null) { return true; } if (filename == null || wildcardMatcher == null) { return false; } if (caseSensitivity == null) { caseSensitivity = IOCase.SENSITIVE; } String[] wcs = splitOnTokens(wildcardMatcher); boolean anyChars = false; int textIdx = 0; int wcsIdx = 0; Stack<int[]> backtrack = new Stack<int[]>(); // loop around a backtrack stack, to handle complex * matching do { if (backtrack.size() > 0) { int[] array = backtrack.pop(); wcsIdx = array[0]; textIdx = array[1]; anyChars = true; } // loop whilst tokens and text left to process while (wcsIdx < wcs.length) { if (wcs[wcsIdx].equals("?")) { // ? so move to next text char textIdx++; if (textIdx > filename.length()) { break; } anyChars = false; } else if (wcs[wcsIdx].equals("*")) { // set any chars status anyChars = true; if (wcsIdx == wcs.length - 1) { textIdx = filename.length(); } } else { // matching text token if (anyChars) { // any chars then try to locate text token textIdx = caseSensitivity.checkIndexOf(filename, textIdx, wcs[wcsIdx]); if (textIdx == -1) { // token not found break; } int repeat = caseSensitivity.checkIndexOf(filename, textIdx + 1, wcs[wcsIdx]); if (repeat >= 0) { backtrack.push(new int[] { wcsIdx, repeat }); } } else { // matching from current position if (!caseSensitivity.checkRegionMatches(filename, textIdx, wcs[wcsIdx])) { // couldnt match token break; } } // matched text token, move text index to end of matched token textIdx += wcs[wcsIdx].length(); anyChars = false; } wcsIdx++; } // full match if (wcsIdx == wcs.length && textIdx == filename.length()) { return true; } } while (backtrack.size() > 0); return false; } /** * Splits a string into a number of tokens. * The text is split by '?' and '*'. * Where multiple '*' occur consecutively they are collapsed into a single '*'. * * @param text the text to split * @return the array of tokens, never null */ static String[] splitOnTokens(String text) { // used by wildcardMatch // package level so a unit test may run on this if (text.indexOf('?') == -1 && text.indexOf('*') == -1) { return new String[] { text }; } char[] array = text.toCharArray(); ArrayList<String> list = new ArrayList<String>(); StringBuilder buffer = new StringBuilder(); for (int i = 0; i < array.length; i++) { if (array[i] == '?' || array[i] == '*') { if (buffer.length() != 0) { list.add(buffer.toString()); buffer.setLength(0); } if (array[i] == '?') { list.add("?"); } else if (list.size() == 0 || (i > 0 && list.get(list.size() - 1).equals("*") == false)) { list.add("*"); } } else { buffer.append(array[i]); } } if (buffer.length() != 0) { list.add(buffer.toString()); } return list.toArray(new String[list.size()]); } }