Java tutorial
/* * Copyright 2002-2019 the original author or authors. * * 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 * * https://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 org.springframework.context; import java.util.EventListener; /** * Interface to be implemented by application event listeners. * * <p>Based on the standard {@code java.util.EventListener} interface * for the Observer design pattern. * * <p>As of Spring 3.0, an {@code ApplicationListener} can generically declare * the event type that it is interested in. When registered with a Spring * {@code ApplicationContext}, events will be filtered accordingly, with the * listener getting invoked for matching event objects only. * * @author Rod Johnson * @author Juergen Hoeller * @param <E> the specific {@code ApplicationEvent} subclass to listen to * @see org.springframework.context.ApplicationEvent * @see org.springframework.context.event.ApplicationEventMulticaster * @see org.springframework.context.event.EventListener */ @FunctionalInterface public interface ApplicationListener<E extends ApplicationEvent> extends EventListener { /** * Handle an application event. * @param event the event to respond to */ void onApplicationEvent(E event); }