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

   1 /*
   2  * Svjatoslav Commons - shared library of common functionality. Author: Svjatoslav Agejenko.
   3  * This project is released under Creative Commons Zero (CC0) license.
   4  */
   5 package eu.svjatoslav.commons.string;
   6
   7 public class GlobMatcher {
   8
   9     /**
  10      * Allow only for * in wildcards
  11      */
  12     private static boolean checkWildCardEnd(final String wildcardExpression,
  13                                             int wildCardPosition) {
  14         for (; wildCardPosition < wildcardExpression.length(); wildCardPosition++) {
  15             final char wildCardChar = wildcardExpression
  16                     .charAt(wildCardPosition);
  17             if (wildCardChar != '*')
  18                 return false;
  19         }
  20
  21         return true;
  22     }
  23
  24     /**
  25      * <pre>
  26      * Test input string against wildcard expression.
  27      * * -- corresponds to any amount of characters.
  28      * ? -- corresponds to any single character.
  29      * </pre>
  30      *
  31      * @param inputString        input string
  32      * @param wildcardExpression wildcard expression
  33      * @return <code>true</code> if input string matches input pattern
  34      */
  35     public static boolean match(final String inputString,
  36                                 final String wildcardExpression) {
  37
  38         if (inputString == null)
  39             return false;
  40
  41         if (wildcardExpression == null)
  42             return false;
  43
  44         int i;
  45
  46         for (i = 0; i < inputString.length(); i++) {
  47             if (i >= wildcardExpression.length())
  48                 return false;
  49             final char wildCardChar = wildcardExpression.charAt(i);
  50             if (wildCardChar == '*')
  51                 return matchPiece(inputString, i, wildcardExpression, i + 1);
  52             if (wildCardChar != '?')
  53                 if (inputString.charAt(i) != wildCardChar)
  54                     return false;
  55         }
  56
  57         return checkWildCardEnd(wildcardExpression, i);
  58     }
  59
  60     private static boolean matchPiece(final String inputString,
  61                                       final int inputStringIndex, final String wildcardExpression,
  62                                       final int wildCardExpressionIndex) {
  63
  64         int wildCardPosition = wildCardExpressionIndex;
  65
  66         for (int i = inputStringIndex; i < inputString.length(); i++) {
  67
  68             wildCardPosition = wildCardExpressionIndex;
  69
  70             subMatchAttempt:
  71             {
  72
  73                 for (int j = i; j < inputString.length(); j++) {
  74                     if (wildCardPosition >= wildcardExpression.length())
  75                         break subMatchAttempt;
  76                     final char wildCardChar = wildcardExpression
  77                             .charAt(wildCardPosition);
  78
  79                     if (wildCardChar == '*')
  80                         return matchPiece(inputString, j, wildcardExpression,
  81                                 wildCardPosition + 1);
  82
  83                     if (wildCardChar != '?')
  84                         if (inputString.charAt(j) != wildCardChar)
  85                             break subMatchAttempt;
  86
  87                     wildCardPosition++;
  88                 }
  89
  90                 return checkWildCardEnd(wildcardExpression, wildCardPosition);
  91             }
  92
  93         }
  94
  95         return checkWildCardEnd(wildcardExpression, wildCardPosition);
  96     }
  97
  98 }