org.kiwiproject.util.regex.KiwiRegexes Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of kiwi Show documentation

Kiwi is a utility library. We really like Google's Guava, and also use Apache Commons. But if they don't have something we need, and we think it is useful, this is where we put it.

There is a newer version: 4.5.2

Show newest version

package org.kiwiproject.util.regex;

import lombok.experimental.UtilityClass;

import java.util.Optional;
import java.util.regex.MatchResult;
import java.util.regex.Pattern;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

/**
 * Static helper methods related to regular expression processing.
 */
@UtilityClass
public class KiwiRegexes {

    /**
     * Extracts a regex match as a String, or return {@code null} if no match found.
     *
     * @param pattern the {@link Pattern}
     * @param input   the input to match against
     * @return a string containing the match, or {@code null} if no match found
     */
    public static String extractMatchOrNull(Pattern pattern, String input) {
        return extractMatch(pattern, input).orElse(null);
    }

    /**
     * Extracts a regex match as a String, or throws an exception if no match found.
     *
     * @param pattern the {@link Pattern}
     * @param input   the input to match against
     * @return a string containing the match
     * @throws NoMatchesFoundException if the input does not match the pattern
     */
    public static String extractMatchOrThrow(Pattern pattern, String input) {
        return extractMatch(pattern, input)
                .orElseThrow(() -> NoMatchesFoundException.forPattern(pattern));
    }

    /**
     * Extracts a regex match as a String.
     *
     * @param pattern the {@link Pattern}
     * @param input   the input to match against
     * @return an Optional containing the match, or empty Optional if no match
     */
    public static Optional extractMatch(Pattern pattern, String input) {
        return extractMatches(pattern, input)
                .map(MatchResult::group)
                .findFirst();
    }

    /**
     * Match an input String against a {@link Pattern} and convert to a {@link Stream} of {@link MatchResult}.
     *
     * @param pattern the {@link Pattern}
     * @param input   the input to match against
     * @return a stream of {@link MatchResult}
     */
    public static Stream extractMatches(Pattern pattern, String input) {
        return StreamSupport.stream(new MatcherSpliterator(pattern.matcher(input)), false);
    }
}