src/main/java/eu/svjatoslav/commons/string/WildCardMatcher.java

   1 /*
   2  * Svjatoslav Commons - shared library of common functionality.
   3  * Copyright ©2012-2013, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public License
   7  * as published by the Free Software Foundation.
   8  */
   9
  10 package eu.svjatoslav.commons.string;
  11
  12 public class WildCardMatcher {
  13
  14         /**
  15          * Allow only for * in wildcards
  16          */
  17         private static boolean checkWildCardEnd(final String wildcardExpression,
  18                         int wildCardPosition) {
  19                 for (; wildCardPosition < wildcardExpression.length(); wildCardPosition++) {
  20                         final char wildCardChar = wildcardExpression
  21                                         .charAt(wildCardPosition);
  22                         if (wildCardChar != '*')
  23                                 return false;
  24                 }
  25
  26                 return true;
  27         }
  28
  29         /**
  30          * <pre>
  31          * Test input string against wildcard expression.
  32          * * -- corresponds to any amount of characters.
  33          * ? -- corresponds to any single character.
  34          * </pre>
  35          */
  36
  37         public static boolean match(final String inputString,
  38                         final String wildcardExpression) {
  39
  40                 int i;
  41
  42                 for (i = 0; i < inputString.length(); i++) {
  43                         if (i >= wildcardExpression.length())
  44                                 return false;
  45                         final char wildCardChar = wildcardExpression.charAt(i);
  46                         if (wildCardChar == '*')
  47                                 return matchPiece(inputString, i, wildcardExpression, i + 1);
  48                         if (wildCardChar != '?')
  49                                 if (inputString.charAt(i) != wildCardChar)
  50                                         return false;
  51                 }
  52
  53                 return checkWildCardEnd(wildcardExpression, i);
  54         }
  55
  56         private static boolean matchPiece(final String inputString,
  57                         final int inputStringIndex, final String wildcardExpression,
  58                         final int wildCardExpressionIndex) {
  59
  60                 int wildCardPosition = wildCardExpressionIndex;
  61
  62                 for (int i = inputStringIndex; i < inputString.length(); i++) {
  63
  64                         wildCardPosition = wildCardExpressionIndex;
  65
  66                         subMatchAttempt: {
  67
  68                                 for (int j = i; j < inputString.length(); j++) {
  69                                         if (wildCardPosition >= wildcardExpression.length())
  70                                                 break subMatchAttempt;
  71                                         final char wildCardChar = wildcardExpression
  72                                                         .charAt(wildCardPosition);
  73
  74                                         if (wildCardChar == '*')
  75                                                 return matchPiece(inputString, j, wildcardExpression,
  76                                                                 wildCardPosition + 1);
  77
  78                                         if (wildCardChar != '?')
  79                                                 if (inputString.charAt(j) != wildCardChar)
  80                                                         break subMatchAttempt;
  81
  82                                         wildCardPosition++;
  83                                 }
  84
  85                                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  86                         }
  87
  88                 }
  89
  90                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  91         }
  92
  93 }