001/**
002 *
003 * Copyright 2019 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.packet.id;
018
019import java.util.concurrent.atomic.AtomicLong;
020
021import org.jivesoftware.smack.util.StringUtils;
022
023public class StandardStanzaIdSource implements StanzaIdSource {
024
025    public static final StandardStanzaIdSource DEFAULT = new StandardStanzaIdSource();
026
027    /**
028     * A prefix helps to make sure that ID's are unique across multiple instances.
029     */
030    private final String prefix = StringUtils.randomString(5) + "-";
031
032    /**
033     * Keeps track of the current increment, which is appended to the prefix to
034     * forum a unique ID.
035     */
036    private final AtomicLong id = new AtomicLong();
037
038    @Override
039    public String getNewStanzaId() {
040        return prefix + Long.toString(id.incrementAndGet());
041    }
042
043    public static class Factory implements StanzaIdSourceFactory {
044
045        @Override
046        public StandardStanzaIdSource constructStanzaIdSource() {
047            return new StandardStanzaIdSource();
048        }
049
050    }
051}