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.logging.log4j.core;
018    
019    import java.io.Serializable;
020    
021    import org.apache.logging.log4j.status.StatusLogger;
022    
023    /**
024     * A life cycle to be extended.
025     * <p>
026     * Wraps a {@link LifeCycle.State}.
027     * </p>
028     */
029    public class AbstractLifeCycle implements LifeCycle, Serializable {
030    
031        /**
032         * Allow subclasses access to the status logger without creating another instance.
033         */
034        protected static final org.apache.logging.log4j.Logger LOGGER = StatusLogger.getLogger();
035    
036        private static final long serialVersionUID = 1L;
037    
038        private volatile LifeCycle.State state = LifeCycle.State.INITIALIZED;
039    
040        protected boolean equalsImpl(final Object obj) {
041            if (this == obj) {
042                return true;
043            }
044            if (obj == null) {
045                return false;
046            }
047            if (getClass() != obj.getClass()) {
048                return false;
049            }
050            final LifeCycle other = (LifeCycle) obj;
051            if (state != other.getState()) {
052                return false;
053            }
054            return true;
055        }
056    
057        @Override
058        public LifeCycle.State getState() {
059            return this.state;
060        }
061    
062        protected int hashCodeImpl() {
063            final int prime = 31;
064            int result = 1;
065            result = prime * result + ((state == null) ? 0 : state.hashCode());
066            return result;
067        }
068    
069        public boolean isInitialized() {
070            return this.state == LifeCycle.State.INITIALIZED;
071        }
072    
073        @Override
074        public boolean isStarted() {
075            return this.state == LifeCycle.State.STARTED;
076        }
077    
078        public boolean isStarting() {
079            return this.state == LifeCycle.State.STARTING;
080        }
081    
082        @Override
083        public boolean isStopped() {
084            return this.state == LifeCycle.State.STOPPED;
085        }
086    
087        public boolean isStopping() {
088            return this.state == LifeCycle.State.STOPPING;
089        }
090    
091        protected void setStarted() {
092            this.setState(LifeCycle.State.STARTED);
093        }
094    
095        protected void setStarting() {
096            this.setState(LifeCycle.State.STARTING);
097        }
098    
099        protected void setState(final LifeCycle.State newState) {
100            this.state = newState;
101            // Need a better string than this.toString() for the message
102            // LOGGER.debug("{} {}", this.state, this);
103        }
104    
105        protected void setStopped() {
106            this.setState(LifeCycle.State.STOPPED);
107        }
108    
109        protected void setStopping() {
110            this.setState(LifeCycle.State.STOPPING);
111        }
112    
113        @Override
114        public void start() {
115            this.setStarted();
116        }
117    
118        @Override
119        public void stop() {
120            this.state = LifeCycle.State.STOPPED;
121        }
122    
123    }