001/**
002 *
003 * Copyright the original author or authors
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.roster.rosterstore;
018
019import java.util.Collection;
020import java.util.List;
021
022import org.jivesoftware.smack.roster.packet.RosterPacket;
023import org.jxmpp.jid.Jid;
024
025/**
026 * This is an interface for persistent roster store needed to implement
027 * roster versioning as per RFC 6121.
028 */
029
030public interface RosterStore {
031
032    /**
033     * This method returns a list of all roster items contained in this store. If there was an error while loading the store, then <code>null</code> is returned.
034     *
035     * @return List of {@link org.jivesoftware.smack.roster.RosterEntry} or <code>null</code>.
036     */
037    public List<RosterPacket.Item> getEntries();
038
039    /**
040     * This method returns the roster item in this store for the given JID.
041     * @param bareJid The bare JID of the RosterEntry
042     * @return The {@link org.jivesoftware.smack.roster.RosterEntry} which belongs to that user
043     */
044    public RosterPacket.Item getEntry(Jid bareJid);
045    /**
046     * This method returns the version number as specified by the "ver" attribute
047     * of the local store. For a fresh store, this MUST be the empty string.
048     * @return local roster version
049     */
050    public String getRosterVersion();
051    /**
052     * This method stores a new roster entry in this store or updates an existing one.
053     * @param item the entry to store
054     * @param version the new roster version
055     * @return True if successful
056     */
057    public boolean addEntry(RosterPacket.Item item, String version);
058    /**
059     * This method updates the store so that it contains only the given entries.
060     * @param items the entries to store
061     * @param version the new roster version
062     * @return True if successful
063     */
064    public boolean resetEntries(Collection<RosterPacket.Item> items, String version);
065    /**
066     * Removes an entry from the store.
067     * @param bareJid The bare JID of the entry to be removed
068     * @param version the new roster version
069     * @return True if successful
070     */
071    public boolean removeEntry(Jid bareJid, String version);
072
073    /**
074     * Reset the store by removing all entries and setting the version to the empty String.
075     *
076     * @since 4.2
077     */
078    public void resetStore();
079}