001    /**
002     * Copyright 2005-2013 The Kuali Foundation
003     *
004     * Licensed under the Educational Community License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.opensource.org/licenses/ecl2.php
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.kuali.rice.kcb.service;
017    
018    import java.lang.reflect.Proxy;
019    
020    import org.apache.log4j.Logger;
021    import org.kuali.rice.kcb.util.BeanFactoryInvocationHandler;
022    import org.springframework.beans.factory.BeanFactory;
023    
024    /**
025     * Class that holds a singleton reference to KCBServiceLocator 
026     * @author Kuali Rice Team (rice.collab@kuali.org)
027     */
028    public class GlobalKCBServiceLocator {
029        private static final Logger LOG = Logger.getLogger(GlobalKCBServiceLocator.class);
030    
031        /**
032         * The KCBServiceLocator singleton
033         */
034        private static KCBServiceLocator locator;
035    
036        /**
037         * The global initializer that constructs the KCBServiceLocator singleton
038         * @param beanFactory the beanFactory from which to construct the KCBServiceLocator
039         */
040        public static synchronized void init(BeanFactory beanFactory) {
041    //        LOG.error("INITIALIZING", new Exception());
042            if (locator != null) {
043                throw new IllegalStateException("GlobalKCBServiceLocator already initialized");
044            }
045    
046            locator = (KCBServiceLocator) Proxy.newProxyInstance(GlobalKCBServiceLocator.class.getClassLoader(),
047                                                                 new Class[] { KCBServiceLocator.class },
048                                                                 new BeanFactoryInvocationHandler(beanFactory));
049        }
050    
051        /**
052         * Returns whether the GlobalKCBServiceLocator has already been initialized (classloader scoped)
053         * @return whether the GlobalKCBServiceLocator has already been initialized (classloader scoped)
054         */
055        public static synchronized boolean isInitialized() {
056            return locator != null;
057        }
058    
059        /**
060         * Un-sets the KCBServiceLocator singleton, in order to fulfill a "lifecycle"
061         * contract (whereby init may be called again in the same class loader), specifically for
062         * unit tests.
063         */
064        public static synchronized void destroy() {
065            //LOG.debug("DESTROYING", new Exception());
066            locator = null;
067        }
068    
069        /**
070         * Returns the KCBServiceLocator singleton
071         * @return the KCBServiceLocator singleton
072         */
073        public static synchronized KCBServiceLocator getInstance() {
074            return locator;
075        }
076    }