Java Wildcard Match wildcardMatches(String pattern, String text)

Description

Check if pattern string matches text string.

License

Apache License

Declaration

public static boolean wildcardMatches(String pattern, String text) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

public class Main {
    /**//  ww  w.ja  v a 2s  .  c om
     * Check if pattern string matches text string.
     *
     * At the beginning of iteration i of main loop
     *
     * old[j] = true if pattern[0..j] matches text[0..i-1]
     *
     * By comparing pattern[j] with text[i], the main loop computes
     *
     * states[j] = true if pattern[0..j] matches text[0..i]
     *
     */
    public static boolean wildcardMatches(String pattern, String text) {
        // add sentinel so don't need to worry about *'s at end of pattern
        text += '\0';
        pattern += '\0';

        int N = pattern.length();

        boolean[] states = new boolean[N + 1];
        boolean[] old = new boolean[N + 1];
        old[0] = true;

        for (int i = 0; i < text.length(); i++) {
            char c = text.charAt(i);
            states = new boolean[N + 1]; // initialized to false
            for (int j = 0; j < N; j++) {
                char p = pattern.charAt(j);

                // hack to handle *'s that match 0 characters
                if (old[j] && (p == '*'))
                    old[j + 1] = true;

                if (old[j] && (p == c))
                    states[j + 1] = true;
                if (old[j] && (p == '.'))
                    states[j + 1] = true;
                if (old[j] && (p == '*'))
                    states[j] = true;
                if (old[j] && (p == '*'))
                    states[j + 1] = true;
            }
            old = states;
        }
        return states[N];
    }
}

Related

1. wildCardMatch(String text, String pattern)
2. wildCardMatch(String text, String pattern)
3. wildCardMatch(String text, String pattern)
4. wildCardMatch(String text, String pattern)
5. wildCardMatch(String text, String wildcard)