001/**
002 * Copyright 2005-2017 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 */
016package org.kuali.rice.ksb.impl.bus;
017
018import org.kuali.rice.ksb.api.bus.Endpoint;
019import org.kuali.rice.ksb.api.bus.ServiceConfiguration;
020import org.kuali.rice.ksb.messaging.serviceconnectors.ServiceConnectorFactory;
021
022public class LazyEndpoint implements Endpoint {
023
024        private final Object lock = new Object();
025        
026        private final ServiceConfiguration serviceConfiguration;
027        private volatile Object service;
028        
029        public LazyEndpoint(ServiceConfiguration serviceConfiguration) {
030                if (serviceConfiguration == null) {
031                        throw new IllegalArgumentException("serviceConfiguration was null");
032                }
033                this.serviceConfiguration = serviceConfiguration;
034        }
035        
036        @Override
037        public ServiceConfiguration getServiceConfiguration() {
038                return this.serviceConfiguration;
039        }
040
041        @Override
042        public Object getService() {
043                // double-checked locking idiom - see Effective Java, Item 71
044                Object internalService = this.service;
045                if (internalService == null) {
046                        synchronized (lock) {
047                                internalService = this.service;
048                                if (internalService == null) {
049                                        this.service = internalService = ServiceConnectorFactory.getServiceConnector(serviceConfiguration).getService(); 
050                                }
051                        }
052                }
053                return internalService;
054        }
055
056}