2 * Sone - Identified.java - Copyright © 2013 David Roden
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 package net.pterodactylus.sone.data;
20 import com.google.common.base.Function;
21 import com.google.common.base.Optional;
24 * Interface for all objects that expose an ID.
26 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
28 public interface Identified {
30 /** Function to extract the ID from an optional. */
31 public static final Function<Optional<? extends Identified>, Optional<String>> GET_ID = new Function<Optional<? extends Identified>, Optional<String>>() {
34 public Optional<String> apply(Optional<? extends Identified> identified) {
35 return identified.isPresent() ? Optional.of(identified.get().getId()) : Optional.<String>absent();
40 * Returns the ID of this element.
42 * @return The ID of this element
44 public String getId();