001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel; 018 019/** 020 * Allows objects to be notified when {@link CamelContext} has almost done all work when starting. 021 * <p/> 022 * The state of {@link CamelContext} may still be in <tt>starting</tt> when this callback is invoked, this is by design. 023 * The callback is invoked during the routes startup procedure when starting {@link CamelContext}. 024 * <p/> 025 * This can be used to perform any custom work when the entire {@link CamelContext} has been initialized and <b>almost</b> 026 * started. This callback is invoked twice during starting the Camel routes, once before the route consumers are started, 027 * and once again after the route consumer has just been started. This is by design to allow Camel components 028 * to react accordingly and for example to register custom startup listeners during starting consumers. 029 * <p/> 030 * If you want to have only one callback after the route consumers has been fully started then use the {@link ExtendedStartupListener} instead. 031 * <p/> 032 * For example the QuartzComponent leverages this to ensure the Quartz scheduler does not start until after all the 033 * Camel routes and services have already been started. 034 * <p/> 035 * <b>Important:</b> You cannot use this listener to add and start new routes to the {@link CamelContext} as this is not 036 * supported by design, as this listener plays a role during starting up routes. Instead you can use an {@link org.apache.camel.spi.EventNotifier} 037 * and listen on the {@link org.apache.camel.spi.CamelEvent.CamelContextStartedEvent} event and then add and start new routes from there. 038 * Instead use the {@link ExtendedStartupListener} if you wish to add new routes. 039 * 040 * @see ExtendedStartupListener 041 */ 042public interface StartupListener { 043 044 /** 045 * Callback invoked when the {@link CamelContext} is about to be fully started (not started yet). 046 * Yes we are aware of the method name, but we can all have a bad-naming day. 047 * 048 * @param context the Camel context 049 * @param alreadyStarted whether or not the {@link CamelContext} already has been started. For example the context 050 * could already have been started, and then a service is added/started later which still 051 * triggers this callback to be invoked. 052 * @throws Exception can be thrown in case of errors to fail the startup process and have the application 053 * fail on startup. 054 */ 055 void onCamelContextStarted(CamelContext context, boolean alreadyStarted) throws Exception; 056}