Java tutorial
/* * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved. * Copyright 2004 The Apache Software Foundation * * 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 javax.servlet.http; import java.util.EventListener; /** * Causes an object to be notified when it is bound to * or unbound from a session. The object is notified * by an {@link HttpSessionBindingEvent} object. This may be as a result * of a servlet programmer explicitly unbinding an attribute from a session, * due to a session being invalidated, or due to a session timing out. * * * @author Various * * @see HttpSession * @see HttpSessionBindingEvent * */ public interface HttpSessionBindingListener extends EventListener { /** * * Notifies the object that it is being bound to * a session and identifies the session. * * @implSpec * The default implementation takes no action. * * @param event the event that identifies the * session * * @see #valueUnbound * */ default public void valueBound(HttpSessionBindingEvent event) { } /** * * Notifies the object that it is being unbound * from a session and identifies the session. * * @implSpec * The default implementation takes no action. * * @param event the event that identifies * the session * * @see #valueBound * */ default public void valueUnbound(HttpSessionBindingEvent event) { } }