/*
    * The Apache Software License, Version 1.1
    *
    * Copyright (c) 2002-2003 The Apache Software Foundation.  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 documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowledgement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.codehaus.org/)."
   *    Alternately, this acknowledgement may appear in the software itself,
   *    if and wherever such third-party acknowledgements normally appear.
   *
   * 4. The names "Ant" and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact codehaus@codehaus.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.codehaus.org/>.
   */
  
  package org.codehaus.plexus.util;
  
  import java.io.File;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.StringTokenizer;
  
  /**
   * <p>This is a utility class used by selectors and DirectoryScanner. The functionality more properly belongs just to
   * selectors, but unfortunately DirectoryScanner exposed these as protected methods. Thus we have to support any
   * subclasses of DirectoryScanner that may access these methods.</p>
   *
   * <p>This is a Singleton.</p>
   *
   * @author Arnout J. Kuiper <a href="mailto:ajkuiper@wxs.nl">ajkuiper@wxs.nl</a>
   * @author Magesh Umasankar
   * @author <a href="mailto:bruce@callenish.com">Bruce Atherton</a>
   *
   * @since 1.5
   */
  public final class SelectorUtils {
  
      public static final String PATTERN_HANDLER_PREFIX = "[";
  
      public static final String PATTERN_HANDLER_SUFFIX = "]";
  
      public static final String REGEX_HANDLER_PREFIX = "%regex" + PATTERN_HANDLER_PREFIX;
  
      public static final String ANT_HANDLER_PREFIX = "%ant" + PATTERN_HANDLER_PREFIX;
  
      private static SelectorUtils instance = new SelectorUtils();
  
      /**
       * Private Constructor
       */
      private SelectorUtils() {}
  
      /**
       * @return Retrieves the manager of the Singleton.
       */
      public static SelectorUtils getInstance() {
          return instance;
      }
  
      /**
      * <p>Tests whether or not a given path matches the start of a given pattern up to the first "**".</p>
      *
      * <p>This is not a general purpose test and should only be used if you can live with false positives. For example,
      * <code>pattern=**\a</code> and <code>str=b</code> will yield <code>true</code>.</p>
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The path to match, as a String. Must not be <code>null</code>.
      * @return whether or not a given path matches the start of a given pattern up to the first "**".
      */
     public static boolean matchPatternStart(String pattern, String str) {
         return matchPatternStart(pattern, str, true);
     }
 
     /**
      * <p>Tests whether or not a given path matches the start of a given pattern up to the first "**".</p>
      *
      * <p>This is not a general purpose test and should only be used if you can live with false positives. For example,
      * <code>pattern=**\a</code> and <code>str=b</code> will yield <code>true</code>.</p>
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The path to match, as a String. Must not be <code>null</code>.
      * @param isCaseSensitive Whether or not matching should be performed case sensitively.
      * @return whether or not a given path matches the start of a given pattern up to the first "**".
      */
     public static boolean matchPatternStart(String pattern, String str, boolean isCaseSensitive) {
         if (isRegexPrefixedPattern(pattern)) {
             // FIXME: ICK! But we can't do partial matches for regex, so we have to reserve judgement until we have
             // a file to deal with, or we can definitely say this is an exclusion...
             return true;
         } else {
             if (isAntPrefixedPattern(pattern)) {
                 pattern = pattern.substring(
                         ANT_HANDLER_PREFIX.length(), pattern.length() - PATTERN_HANDLER_SUFFIX.length());
             }
 
             String altStr = str.replace('\\', '/');
 
             return matchAntPathPatternStart(pattern, str, File.separator, isCaseSensitive)
                     || matchAntPathPatternStart(pattern, altStr, "/", isCaseSensitive);
         }
     }
 
     static boolean isAntPrefixedPattern(String pattern) {
         return pattern.length() > (ANT_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1)
                 && pattern.startsWith(ANT_HANDLER_PREFIX)
                 && pattern.endsWith(PATTERN_HANDLER_SUFFIX);
     }
 
     @SuppressWarnings("SimplifiableIfStatement")
     static boolean matchAntPathPatternStart(
             MatchPattern pattern, String str, String separator, boolean isCaseSensitive) {
         if (separatorPatternStartSlashMismatch(pattern, str, separator)) {
             return false;
         }
 
         return matchAntPathPatternStart(pattern.getTokenizedPathString(), str, separator, isCaseSensitive);
     }
 
     static boolean matchAntPathPatternStart(String pattern, String str, String separator, boolean isCaseSensitive) {
         // When str starts with a File.separator, pattern has to start with a
         // File.separator.
         // When pattern starts with a File.separator, str has to start with a
         // File.separator.
         if (separatorPatternStartSlashMismatch(pattern, str, separator)) {
             return false;
         }
 
         String[] patDirs = tokenizePathToString(pattern, separator);
         return matchAntPathPatternStart(patDirs, str, separator, isCaseSensitive);
     }
 
     // When str starts with a File.separator, pattern has to start with a
     // File.separator.
     // When pattern starts with a File.separator, str has to start with a
     // File.separator.
     private static boolean separatorPatternStartSlashMismatch(String pattern, String str, String separator) {
         return str.startsWith(separator) != pattern.startsWith(separator);
     }
 
     private static boolean separatorPatternStartSlashMismatch(MatchPattern matchPattern, String str, String separator) {
         return str.startsWith(separator) != matchPattern.startsWith(separator);
     }
 
     static boolean matchAntPathPatternStart(String[] patDirs, String str, String separator, boolean isCaseSensitive) {
         String[] strDirs = tokenizePathToString(str, separator);
 
         int patIdxStart = 0;
         int patIdxEnd = patDirs.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.length - 1;
 
         // up to first '**'
         while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
             String patDir = patDirs[patIdxStart];
             if (patDir.equals("**")) {
                 break;
             }
             if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
 
         return strIdxStart > strIdxEnd || patIdxStart <= patIdxEnd;
     }
 
     /**
      * Tests whether or not a given path matches a given pattern.
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The path to match, as a String. Must not be <code>null</code>.
      * @return <code>true</code> if the pattern matches against the string, or <code>false</code> otherwise.
      */
     public static boolean matchPath(String pattern, String str) {
         return matchPath(pattern, str, true);
     }
 
     /**
      * Tests whether or not a given path matches a given pattern.
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The path to match, as a String. Must not be <code>null</code>.
      * @param isCaseSensitive Whether or not matching should be performed case sensitively.
      * @return <code>true</code> if the pattern matches against the string, or <code>false</code> otherwise.
      */
     public static boolean matchPath(String pattern, String str, boolean isCaseSensitive) {
         return matchPath(pattern, str, File.separator, isCaseSensitive);
     }
 
     public static boolean matchPath(String pattern, String str, String separator, boolean isCaseSensitive) {
         if (isRegexPrefixedPattern(pattern)) {
             String localPattern = pattern.substring(
                     REGEX_HANDLER_PREFIX.length(), pattern.length() - PATTERN_HANDLER_SUFFIX.length());
 
             return str.matches(localPattern);
         } else {
             String localPattern = isAntPrefixedPattern(pattern)
                     ? pattern.substring(ANT_HANDLER_PREFIX.length(), pattern.length() - PATTERN_HANDLER_SUFFIX.length())
                     : pattern;
             final String osRelatedPath = toOSRelatedPath(str, separator);
             final String osRelatedPattern = toOSRelatedPath(localPattern, separator);
             return matchAntPathPattern(osRelatedPattern, osRelatedPath, separator, isCaseSensitive);
         }
     }
 
     private static String toOSRelatedPath(String pattern, String separator) {
         if ("/".equals(separator)) {
             return pattern.replace("\\", separator);
         }
         if ("\\".equals(separator)) {
             return pattern.replace("/", separator);
         }
         return pattern;
     }
 
     static boolean isRegexPrefixedPattern(String pattern) {
         return pattern.length() > (REGEX_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1)
                 && pattern.startsWith(REGEX_HANDLER_PREFIX)
                 && pattern.endsWith(PATTERN_HANDLER_SUFFIX);
     }
 
     static boolean matchAntPathPattern(
             MatchPattern matchPattern, String str, String separator, boolean isCaseSensitive) {
         if (separatorPatternStartSlashMismatch(matchPattern, str, separator)) {
             return false;
         }
         String[] patDirs = matchPattern.getTokenizedPathString();
         String[] strDirs = tokenizePathToString(str, separator);
         return matchAntPathPattern(patDirs, strDirs, isCaseSensitive);
     }
 
     static boolean matchAntPathPattern(String pattern, String str, String separator, boolean isCaseSensitive) {
         if (separatorPatternStartSlashMismatch(pattern, str, separator)) {
             return false;
         }
         String[] patDirs = tokenizePathToString(pattern, separator);
         String[] strDirs = tokenizePathToString(str, separator);
         return matchAntPathPattern(patDirs, strDirs, isCaseSensitive);
     }
 
     static boolean matchAntPathPattern(String[] patDirs, String[] strDirs, boolean isCaseSensitive) {
         int patIdxStart = 0;
         int patIdxEnd = patDirs.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.length - 1;
 
         // up to first '**'
         while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
             String patDir = patDirs[patIdxStart];
             if (patDir.equals("**")) {
                 break;
             }
             if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
         if (strIdxStart > strIdxEnd) {
             // String is exhausted
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (!patDirs[i].equals("**")) {
                     return false;
                 }
             }
             return true;
         } else {
             if (patIdxStart > patIdxEnd) {
                 // String not exhausted, but pattern is. Failure.
                 return false;
             }
         }
 
         // up to last '**'
         while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
             String patDir = patDirs[patIdxEnd];
             if (patDir.equals("**")) {
                 break;
             }
             if (!match(patDir, strDirs[strIdxEnd], isCaseSensitive)) {
                 return false;
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if (strIdxStart > strIdxEnd) {
             // String is exhausted
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (!patDirs[i].equals("**")) {
                     return false;
                 }
             }
             return true;
         }
 
         while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
             int patIdxTmp = -1;
             for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                 if (patDirs[i].equals("**")) {
                     patIdxTmp = i;
                     break;
                 }
             }
             if (patIdxTmp == patIdxStart + 1) {
                 // '**/**' situation, so skip one
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = (patIdxTmp - patIdxStart - 1);
             int strLength = (strIdxEnd - strIdxStart + 1);
             int foundIdx = -1;
             strLoop:
             for (int i = 0; i <= strLength - patLength; i++) {
                 for (int j = 0; j < patLength; j++) {
                     String subPat = patDirs[patIdxStart + j + 1];
                     String subStr = strDirs[strIdxStart + i + j];
                     if (!match(subPat, subStr, isCaseSensitive)) {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if (foundIdx == -1) {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         for (int i = patIdxStart; i <= patIdxEnd; i++) {
             if (!patDirs[i].equals("**")) {
                 return false;
             }
         }
 
         return true;
     }
 
     static boolean matchAntPathPattern(char[][] patDirs, char[][] strDirs, boolean isCaseSensitive) {
         int patIdxStart = 0;
         int patIdxEnd = patDirs.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.length - 1;
 
         // up to first '**'
         while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
             char[] patDir = patDirs[patIdxStart];
             if (isDoubleStar(patDir)) {
                 break;
             }
             if (!match(patDir, strDirs[strIdxStart], isCaseSensitive)) {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
         if (strIdxStart > strIdxEnd) {
             // String is exhausted
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (!isDoubleStar(patDirs[i])) {
                     return false;
                 }
             }
             return true;
         } else {
             if (patIdxStart > patIdxEnd) {
                 // String not exhausted, but pattern is. Failure.
                 return false;
             }
         }
 
         // up to last '**'
         while (patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd) {
             char[] patDir = patDirs[patIdxEnd];
             if (isDoubleStar(patDir)) {
                 break;
             }
             if (!match(patDir, strDirs[strIdxEnd], isCaseSensitive)) {
                 return false;
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if (strIdxStart > strIdxEnd) {
             // String is exhausted
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (!isDoubleStar(patDirs[i])) {
                     return false;
                 }
             }
             return true;
         }
 
         while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
             int patIdxTmp = -1;
             for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                 if (isDoubleStar(patDirs[i])) {
                     patIdxTmp = i;
                     break;
                 }
             }
             if (patIdxTmp == patIdxStart + 1) {
                 // '**/**' situation, so skip one
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = (patIdxTmp - patIdxStart - 1);
             int strLength = (strIdxEnd - strIdxStart + 1);
             int foundIdx = -1;
             strLoop:
             for (int i = 0; i <= strLength - patLength; i++) {
                 for (int j = 0; j < patLength; j++) {
                     char[] subPat = patDirs[patIdxStart + j + 1];
                     char[] subStr = strDirs[strIdxStart + i + j];
                     if (!match(subPat, subStr, isCaseSensitive)) {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if (foundIdx == -1) {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         for (int i = patIdxStart; i <= patIdxEnd; i++) {
             if (!isDoubleStar(patDirs[i])) {
                 return false;
             }
         }
 
         return true;
     }
 
     private static boolean isDoubleStar(char[] patDir) {
         return patDir != null && patDir.length == 2 && patDir[0] == '*' && patDir[1] == '*';
     }
 
     /**
      * Tests whether or not a string matches against a pattern. The pattern may contain two special characters:<br>
      * '*' means zero or more characters<br>
      * '?' means one and only one character
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The string which must be matched against the pattern. Must not be <code>null</code>.
      * @return <code>true</code> if the string matches against the pattern, or <code>false</code> otherwise.
      */
     public static boolean match(String pattern, String str) {
         return match(pattern, str, true);
     }
 
     /**
      * Tests whether or not a string matches against a pattern. The pattern may contain two special characters:<br>
      * '*' means zero or more characters<br>
      * '?' means one and only one character
      *
      * @param pattern The pattern to match against. Must not be <code>null</code>.
      * @param str The string which must be matched against the pattern. Must not be <code>null</code>.
      * @param isCaseSensitive Whether or not matching should be performed case sensitively.
      * @return <code>true</code> if the string matches against the pattern, or <code>false</code> otherwise.
      */
     public static boolean match(String pattern, String str, boolean isCaseSensitive) {
         char[] patArr = pattern.toCharArray();
         char[] strArr = str.toCharArray();
         return match(patArr, strArr, isCaseSensitive);
     }
 
     public static boolean match(char[] patArr, char[] strArr, boolean isCaseSensitive) {
         int patIdxStart = 0;
         int patIdxEnd = patArr.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strArr.length - 1;
         char ch;
 
         boolean containsStar = false;
         for (char aPatArr : patArr) {
             if (aPatArr == '*') {
                 containsStar = true;
                 break;
             }
         }
 
         if (!containsStar) {
             // No '*'s, so we make a shortcut
             if (patIdxEnd != strIdxEnd) {
                 return false; // Pattern and string do not have the same size
             }
             for (int i = 0; i <= patIdxEnd; i++) {
                 ch = patArr[i];
                 if (ch != '?' && !equals(ch, strArr[i], isCaseSensitive)) {
                     return false; // Character mismatch
                 }
             }
             return true; // String matches against pattern
         }
 
         if (patIdxEnd == 0) {
             return true; // Pattern contains only '*', which matches anything
         }
 
         // Process characters before first star
         while ((ch = patArr[patIdxStart]) != '*' && strIdxStart <= strIdxEnd) {
             if (ch != '?' && !equals(ch, strArr[strIdxStart], isCaseSensitive)) {
                 return false; // Character mismatch
             }
             patIdxStart++;
             strIdxStart++;
         }
         if (strIdxStart > strIdxEnd) {
             // All characters in the string are used. Check if only '*'s are
             // left in the pattern. If so, we succeeded. Otherwise failure.
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (patArr[i] != '*') {
                     return false;
                 }
             }
             return true;
         }
 
         // Process characters after last star
         while ((ch = patArr[patIdxEnd]) != '*' && strIdxStart <= strIdxEnd) {
             if (ch != '?' && !equals(ch, strArr[strIdxEnd], isCaseSensitive)) {
                 return false; // Character mismatch
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if (strIdxStart > strIdxEnd) {
             // All characters in the string are used. Check if only '*'s are
             // left in the pattern. If so, we succeeded. Otherwise failure.
             for (int i = patIdxStart; i <= patIdxEnd; i++) {
                 if (patArr[i] != '*') {
                     return false;
                 }
             }
             return true;
         }
 
         // process pattern between stars. padIdxStart and patIdxEnd point
         // always to a '*'.
         while (patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd) {
             int patIdxTmp = -1;
             for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
                 if (patArr[i] == '*') {
                     patIdxTmp = i;
                     break;
                 }
             }
             if (patIdxTmp == patIdxStart + 1) {
                 // Two stars next to each other, skip the first one.
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = (patIdxTmp - patIdxStart - 1);
             int strLength = (strIdxEnd - strIdxStart + 1);
             int foundIdx = -1;
             strLoop:
             for (int i = 0; i <= strLength - patLength; i++) {
                 for (int j = 0; j < patLength; j++) {
                     ch = patArr[patIdxStart + j + 1];
                     if (ch != '?' && !equals(ch, strArr[strIdxStart + i + j], isCaseSensitive)) {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if (foundIdx == -1) {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         // All characters in the string are used. Check if only '*'s are left
         // in the pattern. If so, we succeeded. Otherwise failure.
         for (int i = patIdxStart; i <= patIdxEnd; i++) {
             if (patArr[i] != '*') {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * Tests whether two characters are equal.
      */
     private static boolean equals(char c1, char c2, boolean isCaseSensitive) {
         if (c1 == c2) {
             return true;
         }
         if (!isCaseSensitive) {
             // NOTE: Try both upper case and lower case as done by String.equalsIgnoreCase()
             if (Character.toUpperCase(c1) == Character.toUpperCase(c2)
                     || Character.toLowerCase(c1) == Character.toLowerCase(c2)) {
                 return true;
             }
         }
         return false;
     }
 
     private static String[] tokenizePathToString(String path, String separator) {
         List<String> ret = new ArrayList<String>();
         StringTokenizer st = new StringTokenizer(path, separator);
         while (st.hasMoreTokens()) {
             ret.add(st.nextToken());
         }
         return ret.toArray(new String[0]);
     }
 
     /**
      * Returns dependency information on these two files. If src has been modified later than target, it returns true.
      * If target doesn't exist, it likewise returns true. Otherwise, target is newer than src and is not out of date,
      * thus the method returns false. It also returns false if the src file doesn't even exist, since how could the
      * target then be out of date.
      *
      * @param src the original file
      * @param target the file being compared against
      * @param granularity the amount in seconds of slack we will give in determining out of dateness
      * @return whether the target is out of date
      */
     public static boolean isOutOfDate(File src, File target, int granularity) {
         if (!src.exists()) {
             return false;
         }
         if (!target.exists()) {
             return true;
         }
         if ((src.lastModified() - granularity) > target.lastModified()) {
             return true;
         }
         return false;
     }
 
     /**
      * "Flattens" a string by removing all whitespace (space, tab, linefeed, carriage return, and formfeed). This uses
      * StringTokenizer and the default set of tokens as documented in the single argument constructor.
      *
      * @param input a String to remove all whitespace.
      * @return a String that has had all whitespace removed.
      */
     public static String removeWhitespace(String input) {
         StringBuilder result = new StringBuilder();
         if (input != null) {
             StringTokenizer st = new StringTokenizer(input);
             while (st.hasMoreTokens()) {
                 result.append(st.nextToken());
             }
         }
         return result.toString();
     }
 }