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     */
017    package org.apache.xbean.kernel;
018    
019    /**
020     * This interface is used to monitor service lifecycle events.  A ServiceMonitor can be registered with a kernel using
021     * {@link Kernel#addServiceMonitor(ServiceMonitor)} or {@link Kernel#addServiceMonitor(ServiceMonitor, ServiceName)}.
022     *
023     * @author Dain Sundstrom
024     * @version $Id$
025     * @since 2.0
026     */
027    public interface ServiceMonitor {
028        /**
029         * A new service has been registered with the kernel.
030         *
031         * @param serviceEvent the event information
032         */
033        void serviceRegistered(ServiceEvent serviceEvent);
034    
035        /**
036         * A service has entered the STARTING state.
037         *
038         * @param serviceEvent the event information
039         */
040        void serviceStarting(ServiceEvent serviceEvent);
041    
042        /**
043         * A service is waiting to start because some start conditions are unsatified.
044         *
045         * @param serviceEvent the event information
046         * @see ServiceEvent#getUnsatisfiedConditions()
047         */
048        void serviceWaitingToStart(ServiceEvent serviceEvent);
049    
050        /**
051         * An error occured while calling creating the service.
052         *
053         * @param serviceEvent the event information
054         * @see ServiceEvent#getCause()
055         */
056        void serviceStartError(ServiceEvent serviceEvent);
057    
058        /**
059         * A service has entered the RUNNING state.
060         *
061         * @param serviceEvent the event information
062         */
063        void serviceRunning(ServiceEvent serviceEvent);
064    
065        /**
066         * A service has entered the RUNNING state.
067         *
068         * @param serviceEvent the event information
069         */
070        void serviceStopping(ServiceEvent serviceEvent);
071    
072        /**
073         * A service is waiting to stop because some stop condition is unsatified.
074         *
075         * @param serviceEvent the event information
076         * @see ServiceEvent#getUnsatisfiedConditions()
077         */
078        void serviceWaitingToStop(ServiceEvent serviceEvent);
079    
080        /**
081         * An error occured while calling destroying the service.
082         *
083         * @param serviceEvent the event information
084         * @see ServiceEvent#getCause()
085         */
086        void serviceStopError(ServiceEvent serviceEvent);
087    
088        /**
089         * A service has entered the STOPPED state.
090         *
091         * @param serviceEvent the event information
092         */
093        void serviceStopped(ServiceEvent serviceEvent);
094    
095        /**
096         * A service has been unregistered from the kernel.
097         *
098         * @param serviceEvent the event information
099         */
100        void serviceUnregistered(ServiceEvent serviceEvent);
101    }