javax.servlet.http.HttpSessionAttributeListener Maven / Gradle / Ivy
/*
* 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;
/**
* Interface for receiving notification events about HttpSession
* attribute changes.
*
* In order to receive these notification events, the implementation
* class must be either declared in the deployment descriptor of the web
* application, annotated with {@link javax.servlet.annotation.WebListener},
* or registered via one of the addListener methods defined on
* {@link javax.servlet.ServletContext}.
*
*
The order in which implementations of this interface are invoked is
* unspecified.
*
* @since Servlet 2.3
*/
public interface HttpSessionAttributeListener extends EventListener {
/**
* Receives notification that an attribute has been added to a
* session.
*
* @param event the HttpSessionBindingEvent containing the session
* and the name and value of the attribute that was added
*/
default public void attributeAdded(HttpSessionBindingEvent event) {}
/**
* Receives notification that an attribute has been removed from a
* session.
*
* @param event the HttpSessionBindingEvent containing the session
* and the name and value of the attribute that was removed
*/
default public void attributeRemoved(HttpSessionBindingEvent event) {}
/**
* Receives notification that an attribute has been replaced in a
* session.
*
* @param event the HttpSessionBindingEvent containing the session
* and the name and (old) value of the attribute that was replaced
*/
default public void attributeReplaced(HttpSessionBindingEvent event) {}
}