001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.shiro.session;
020
021/**
022 * Interface to be implemented by components that wish to be notified of events that occur during a
023 * {@link Session Session}'s life cycle.
024 *
025 * @since 0.9
026 */
027public interface SessionListener {
028
029    /**
030     * Notification callback that occurs when the corresponding Session has started.
031     *
032     * @param session the session that has started.
033     */
034    void onStart(Session session);
035
036    /**
037     * Notification callback that occurs when the corresponding Session has stopped, either programmatically via
038     * {@link Session#stop} or automatically upon a subject logging out.
039     *
040     * @param session the session that has stopped.
041     */
042    void onStop(Session session);
043
044    /**
045     * Notification callback that occurs when the corresponding Session has expired.
046     * <p/>
047     * <b>Note</b>: this method is almost never called at the exact instant that the {@code Session} expires.  Almost all
048     * session management systems, including Shiro's implementations, lazily validate sessions - either when they
049     * are accessed or during a regular validation interval.  It would be too resource intensive to monitor every
050     * single session instance to know the exact instant it expires.
051     * <p/>
052     * If you need to perform time-based logic when a session expires, it is best to write it based on the
053     * session's {@link org.apache.shiro.session.Session#getLastAccessTime() lastAccessTime} and <em>not</em> the time
054     * when this method is called.
055     *
056     * @param session the session that has expired.
057     */
058    void onExpiration(Session session);
059}