Regular Expression Wildcard Matching

Question

I have a list of about 120 thousand english words (basically every word in the language).

I need a regular expression that would allow searching through these words

Answer 1

This is what I use:

String wildcardToRegex(String wildcardString) {
    // The 12 is arbitrary, you may adjust it to fit your needs depending
    // on how many special characters you expect in a single pattern.
    StringBuilder sb = new StringBuilder(wildcardString.length() + 12);
    sb.append('^');
    for (int i = 0; i < wildcardString.length(); ++i) {
        char c = wildcardString.charAt(i);
        if (c == '*') {
            sb.append(".*");
        } else if (c == '?') {
            sb.append('.');
        } else if ("\\.[]{}()+-^$|".indexOf(c) >= 0) {
            sb.append('\\');
            sb.append(c);
        } else {
            sb.append(c);
        }
    }
    sb.append('$');
    return sb.toString();
}

Special character list from https://stackoverflow.com/a/26228852/1808989.