Line data    Source code

       1             : // Copyright (C) 2014 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.server.change;
      16             : 
      17             : import com.google.common.base.CharMatcher;
      18             : import com.google.common.base.Strings;
      19             : import java.util.Collections;
      20             : import java.util.HashSet;
      21             : import java.util.Set;
      22             : import java.util.regex.Matcher;
      23             : import java.util.regex.Pattern;
      24             : 
      25             : public class HashtagsUtil {
      26             :   public static class InvalidHashtagException extends Exception {
      27             :     private static final long serialVersionUID = 1L;
      28             : 
      29             :     static InvalidHashtagException hashtagsMayNotContainCommas() {
      30           1 :       return new InvalidHashtagException("hashtags may not contain commas");
      31             :     }
      32             : 
      33             :     InvalidHashtagException(String message) {
      34           1 :       super(message);
      35           1 :     }
      36             :   }
      37             : 
      38           9 :   private static final CharMatcher LEADER = CharMatcher.whitespace().or(CharMatcher.is('#'));
      39             :   private static final String PATTERN = "(?:\\s|\\A)#[\\p{L}[0-9]-_]+";
      40             : 
      41             :   public static String cleanupHashtag(String hashtag) {
      42           9 :     hashtag = LEADER.trimLeadingFrom(hashtag);
      43           9 :     hashtag = CharMatcher.whitespace().trimTrailingFrom(hashtag);
      44           9 :     return hashtag;
      45             :   }
      46             : 
      47             :   public static Set<String> extractTags(String input) {
      48           1 :     Set<String> result = new HashSet<>();
      49           1 :     if (!Strings.isNullOrEmpty(input)) {
      50           1 :       Matcher matcher = Pattern.compile(PATTERN).matcher(input);
      51           1 :       while (matcher.find()) {
      52           1 :         result.add(cleanupHashtag(matcher.group()));
      53             :       }
      54             :     }
      55           1 :     return result;
      56             :   }
      57             : 
      58             :   static Set<String> extractTags(Set<String> input) throws InvalidHashtagException {
      59           8 :     if (input == null) {
      60           8 :       return Collections.emptySet();
      61             :     }
      62           8 :     HashSet<String> result = new HashSet<>();
      63           8 :     for (String hashtag : input) {
      64           8 :       if (hashtag.contains(",")) {
      65           1 :         throw InvalidHashtagException.hashtagsMayNotContainCommas();
      66             :       }
      67           8 :       hashtag = cleanupHashtag(hashtag);
      68           8 :       if (!hashtag.isEmpty()) {
      69           8 :         result.add(hashtag);
      70             :       }
      71           8 :     }
      72           8 :     return result;
      73             :   }
      74             : 
      75             :   private HashtagsUtil() {}
      76             : }