com.google.gerrit.server.change.HashtagsUtil Maven / Gradle / Ivy
// 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 extractTags(String input) {
Set 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 extractTags(Set input) throws InvalidHashtagException {
if (input == null) {
return Collections.emptySet();
}
HashSet 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() {}
}