Class WildcardMatcherHelper

  • public class WildcardMatcherHelper
    extends Object
    This class is an utility class that perform wildcard-patterns matching and isolation.
    $Id: 420832 2006-07-11 13:11:02Z cziegeler $
    • Method Detail

      • match

        public static Map<String,​Stringmatch​(String pat,
                                                     String str)
        Match a pattern against a string and isolates wildcard replacement into a Map.
        Here is how the matching algorithm works:
        • The '*' character, meaning that zero or more characters (excluding the path separator '/') are to be matched.
        • The '**' sequence, meaning that zero or more characters (including the path separator '/') are to be matched.
        • The '\*' sequence is honored as a literal '*' character, not a wildcard

        When more than two '*' characters, not separated by another character, are found their value is considered as '**' and immediate succeeding '*' are skipped.
        The '**' wildcard is greedy and thus the following sample cannot match:
        STAR,STAR,PATHSEP,STAR,PATHSEP,STAR,STAR (why can't I express it literally?)
        The first '**' in the pattern will suck up until the last '/' in string and thus will not match.
        A more advance algorithm could certainly check whether there is an other literal later in the pattern to ev. match in string but I'll leave this exercise to someone else ATM if one needs such.
        pat - The pattern string.
        str - The string to math against the pattern
        a Map containing the representation of the extracted pattern. The extracted patterns are keys in the Map from left to right beginning with "1" for the left most, "2" for the next, a.s.o. The key "0" is the string itself. If the return value is null, string does not match to the pattern .