jakarta.servlet.ServletContextAttributeListener Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2023 Oracle and/or its affiliates and others.
* 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 jakarta.servlet;
import java.util.EventListener;
/**
* Interface for receiving notification events about ServletContext 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 jakarta.servlet.annotation.WebListener}, or registered via
* one of the addListener methods defined on {@link ServletContext}.
*
*
* The order in which implementations of this interface are invoked is unspecified.
*
* @see ServletContextAttributeEvent
*
* @since Servlet 2.3
*/
public interface ServletContextAttributeListener extends EventListener {
/**
* Receives notification that an attribute has been added to the ServletContext.
*
* @param event the ServletContextAttributeEvent containing the ServletContext to which the attribute was added, along
* with the attribute name and value
*
* @implSpec The default implementation takes no action.
*/
default void attributeAdded(ServletContextAttributeEvent event) {
}
/**
* Receives notification that an attribute has been removed from the ServletContext.
*
* @param event the ServletContextAttributeEvent containing the ServletContext from which the attribute was removed,
* along with the attribute name and value
*
* @implSpec The default implementation takes no action.
*/
default void attributeRemoved(ServletContextAttributeEvent event) {
}
/**
* Receives notification that an attribute has been replaced in the ServletContext.
*
* @param event the ServletContextAttributeEvent containing the ServletContext in which the attribute was replaced,
* along with the attribute name and its old value
*
* @implSpec The default implementation takes no action.
*/
default void attributeReplaced(ServletContextAttributeEvent event) {
}
}