001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.util;
020    
021    import org.apache.shiro.ShiroException;
022    import org.slf4j.Logger;
023    import org.slf4j.LoggerFactory;
024    
025    import java.util.Collection;
026    
027    
028    /**
029     * Utility class to help call {@link org.apache.shiro.util.Initializable#init() Initializable.init()} and
030     * {@link org.apache.shiro.util.Destroyable#destroy() Destroyable.destroy()} methods cleanly on any object.
031     *
032     * @since 0.2
033     */
034    public abstract class LifecycleUtils {
035    
036        private static final Logger log = LoggerFactory.getLogger(LifecycleUtils.class);
037    
038        public static void init(Object o) throws ShiroException {
039            if (o instanceof Initializable) {
040                init((Initializable) o);
041            }
042        }
043    
044        public static void init(Initializable initializable) throws ShiroException {
045            initializable.init();
046        }
047    
048        /**
049         * Calls {@link #init(Object) init} for each object in the collection.  If the collection is {@code null} or empty,
050         * this method returns quietly.
051         *
052         * @param c the collection containing objects to {@link #init init}.
053         * @throws ShiroException if unable to initialize one or more instances.
054         * @since 0.9
055         */
056        public static void init(Collection c) throws ShiroException {
057            if (c == null || c.isEmpty()) {
058                return;
059            }
060            for (Object o : c) {
061                init(o);
062            }
063        }
064    
065        public static void destroy(Object o) {
066            if (o instanceof Destroyable) {
067                destroy((Destroyable) o);
068            } else if (o instanceof Collection) {
069                destroy((Collection)o);
070            }
071        }
072    
073        public static void destroy(Destroyable d) {
074            if (d != null) {
075                try {
076                    d.destroy();
077                } catch (Throwable t) {
078                    if (log.isDebugEnabled()) {
079                        String msg = "Unable to cleanly destroy instance [" + d + "] of type [" + d.getClass().getName() + "].";
080                        log.debug(msg, t);
081                    }
082                }
083            }
084        }
085    
086        /**
087         * Calls {@link #destroy(Object) destroy} for each object in the collection.
088         * If the collection is {@code null} or empty, this method returns quietly.
089         *
090         * @param c the collection of objects to destroy.
091         * @since 0.9
092         */
093        public static void destroy(Collection c) {
094            if (c == null || c.isEmpty()) {
095                return;
096            }
097    
098            for (Object o : c) {
099                destroy(o);
100            }
101        }
102    }