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

   1 /*
   2  * Svjatoslav Commons - shared library of common functionality.
   3  * Copyright ©2012-2014, 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 3 of the GNU Lesser General Public License
   7  * or later 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          * @param inputString
  37          *            input string
  38          * @param wildcardExpression
  39          *            wildcard expression
  40          * @return <code>true</code> if input string matches input pattern
  41          */
  42         public static boolean match(final String inputString,
  43                         final String wildcardExpression) {
  44
  45                 if (inputString == null)
  46                         return false;
  47
  48                 if (wildcardExpression == null)
  49                         return false;
  50
  51                 int i;
  52
  53                 for (i = 0; i < inputString.length(); i++) {
  54                         if (i >= wildcardExpression.length())
  55                                 return false;
  56                         final char wildCardChar = wildcardExpression.charAt(i);
  57                         if (wildCardChar == '*')
  58                                 return matchPiece(inputString, i, wildcardExpression, i + 1);
  59                         if (wildCardChar != '?')
  60                                 if (inputString.charAt(i) != wildCardChar)
  61                                         return false;
  62                 }
  63
  64                 return checkWildCardEnd(wildcardExpression, i);
  65         }
  66
  67         private static boolean matchPiece(final String inputString,
  68                         final int inputStringIndex, final String wildcardExpression,
  69                         final int wildCardExpressionIndex) {
  70
  71                 int wildCardPosition = wildCardExpressionIndex;
  72
  73                 for (int i = inputStringIndex; i < inputString.length(); i++) {
  74
  75                         wildCardPosition = wildCardExpressionIndex;
  76
  77                         subMatchAttempt: {
  78
  79                                 for (int j = i; j < inputString.length(); j++) {
  80                                         if (wildCardPosition >= wildcardExpression.length())
  81                                                 break subMatchAttempt;
  82                                         final char wildCardChar = wildcardExpression
  83                                                         .charAt(wildCardPosition);
  84
  85                                         if (wildCardChar == '*')
  86                                                 return matchPiece(inputString, j, wildcardExpression,
  87                                                                 wildCardPosition + 1);
  88
  89                                         if (wildCardChar != '?')
  90                                                 if (inputString.charAt(j) != wildCardChar)
  91                                                         break subMatchAttempt;
  92
  93                                         wildCardPosition++;
  94                                 }
  95
  96                                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  97                         }
  98
  99                 }
 100
 101                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
 102         }
 103
 104 }