| // Copyright (C) 2014 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.server.change; |
| |
| import com.google.common.base.CharMatcher; |
| import com.google.common.base.Strings; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Set; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| public class HashtagsUtil { |
| public static class InvalidHashtagException extends Exception { |
| private static final long serialVersionUID = 1L; |
| |
| static InvalidHashtagException hashtagsMayNotContainCommas() { |
| return new InvalidHashtagException("hashtags may not contain commas"); |
| } |
| |
| InvalidHashtagException(String message) { |
| super(message); |
| } |
| } |
| |
| private static final CharMatcher LEADER = CharMatcher.whitespace().or(CharMatcher.is('#')); |
| private static final String PATTERN = "(?:\\s|\\A)#[\\p{L}[0-9]-_]+"; |
| |
| public static String cleanupHashtag(String hashtag) { |
| hashtag = LEADER.trimLeadingFrom(hashtag); |
| hashtag = CharMatcher.whitespace().trimTrailingFrom(hashtag); |
| return hashtag; |
| } |
| |
| public static Set<String> extractTags(String input) { |
| Set<String> result = new HashSet<>(); |
| if (!Strings.isNullOrEmpty(input)) { |
| Matcher matcher = Pattern.compile(PATTERN).matcher(input); |
| while (matcher.find()) { |
| result.add(cleanupHashtag(matcher.group())); |
| } |
| } |
| return result; |
| } |
| |
| static Set<String> extractTags(Set<String> input) throws InvalidHashtagException { |
| if (input == null) { |
| return Collections.emptySet(); |
| } |
| HashSet<String> result = new HashSet<>(); |
| for (String hashtag : input) { |
| if (hashtag.contains(",")) { |
| throw InvalidHashtagException.hashtagsMayNotContainCommas(); |
| } |
| hashtag = cleanupHashtag(hashtag); |
| if (!hashtag.isEmpty()) { |
| result.add(hashtag); |
| } |
| } |
| return result; |
| } |
| |
| private HashtagsUtil() {} |
| } |