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                 if (inputString == null)
  41                         return false;
  42
  43                 if (wildcardExpression == null)
  44                         return false;
  45
  46                 int i;
  47
  48                 for (i = 0; i < inputString.length(); i++) {
  49                         if (i >= wildcardExpression.length())
  50                                 return false;
  51                         final char wildCardChar = wildcardExpression.charAt(i);
  52                         if (wildCardChar == '*')
  53                                 return matchPiece(inputString, i, wildcardExpression, i + 1);
  54                         if (wildCardChar != '?')
  55                                 if (inputString.charAt(i) != wildCardChar)
  56                                         return false;
  57                 }
  58
  59                 return checkWildCardEnd(wildcardExpression, i);
  60         }
  61
  62         private static boolean matchPiece(final String inputString,
  63                         final int inputStringIndex, final String wildcardExpression,
  64                         final int wildCardExpressionIndex) {
  65
  66                 int wildCardPosition = wildCardExpressionIndex;
  67
  68                 for (int i = inputStringIndex; i < inputString.length(); i++) {
  69
  70                         wildCardPosition = wildCardExpressionIndex;
  71
  72                         subMatchAttempt: {
  73
  74                                 for (int j = i; j < inputString.length(); j++) {
  75                                         if (wildCardPosition >= wildcardExpression.length())
  76                                                 break subMatchAttempt;
  77                                         final char wildCardChar = wildcardExpression
  78                                                         .charAt(wildCardPosition);
  79
  80                                         if (wildCardChar == '*')
  81                                                 return matchPiece(inputString, j, wildcardExpression,
  82                                                                 wildCardPosition + 1);
  83
  84                                         if (wildCardChar != '?')
  85                                                 if (inputString.charAt(j) != wildCardChar)
  86                                                         break subMatchAttempt;
  87
  88                                         wildCardPosition++;
  89                                 }
  90
  91                                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  92                         }
  93
  94                 }
  95
  96                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  97         }
  98
  99 }