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