001    /**
002     * Copyright 2005-2014 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.ksb.messaging;
017    
018    import org.apache.log4j.Logger;
019    import org.kuali.rice.core.api.config.property.ConfigContext;
020    import org.kuali.rice.ksb.messaging.service.MessageQueueService;
021    import org.kuali.rice.ksb.service.KSBServiceLocator;
022    import org.kuali.rice.ksb.util.KSBConstants;
023    import org.springframework.transaction.TransactionStatus;
024    import org.springframework.transaction.support.TransactionCallback;
025    
026    /**
027     * Fetches messages from the db. Marks as 'R'. Gives messages to ThreadPool for execution
028     *
029     * @author Kuali Rice Team (rice.collab@kuali.org)
030     */
031    public class MessageFetcher implements Runnable {
032    
033        private static final Logger LOG = Logger.getLogger(MessageFetcher.class);
034    
035        private Integer maxMessages;
036        private Long routeQueueId;
037    
038        public MessageFetcher(Integer maxMessages) {
039            this.maxMessages = maxMessages;
040        }
041    
042        public MessageFetcher(Long routeQueueId) {
043            this.routeQueueId = routeQueueId;
044        }
045    
046        public void run() {
047            if (ConfigContext.getCurrentContextConfig().getBooleanProperty(KSBConstants.Config.MESSAGE_PERSISTENCE,
048                    false)) {
049                try {
050                    requeueDocument();
051                    requeueMessages();
052                } catch (Throwable t) {
053                    LOG.error("Failed to fetch messages.", t);
054                }
055            }
056        }
057    
058        private void requeueMessages() {
059            if (this.routeQueueId == null) {
060                try {
061                    for (PersistedMessageBO message : getRouteQueueService().getNextDocuments(maxMessages)) {
062                        message = markEnrouteAndSaveMessage(message);
063                        executeMessage(message);
064                    }
065                } catch (Throwable t) {
066                    LOG.error("Failed to fetch or process some messages during requeueMessages", t);
067                }
068            }
069        }
070    
071        private void requeueDocument() {
072            try {
073                if (this.routeQueueId != null) {
074                    PersistedMessageBO message = getRouteQueueService().findByRouteQueueId(this.routeQueueId);
075                    message.setQueueStatus(KSBConstants.ROUTE_QUEUE_ROUTING);
076                    message = getRouteQueueService().save(message);
077                    executeMessage(message);
078                }
079            } catch (Throwable t) {
080                LOG.error("Failed to fetch or process some messages during requeueDocument", t);
081            }
082        }
083    
084        private void executeMessage(PersistedMessageBO message) {
085            try {
086                KSBServiceLocator.getThreadPool().execute(new MessageServiceInvoker(message));
087            } catch (Throwable t) {
088                LOG.error("Failed to place message " + message + " in thread pool for execution", t);
089            }
090        }
091    
092        private PersistedMessageBO markEnrouteAndSaveMessage(final PersistedMessageBO message) {
093            try {
094                return KSBServiceLocator.getTransactionTemplate().execute(new TransactionCallback<PersistedMessageBO>() {
095                    public PersistedMessageBO doInTransaction(TransactionStatus status) {
096                        message.setQueueStatus(KSBConstants.ROUTE_QUEUE_ROUTING);
097                        return getRouteQueueService().save(message);
098                    }
099                });
100            } catch (Throwable t) {
101                LOG.error("Caught error attempting to mark message " + message + " as R", t);
102            }
103            return message;
104        }
105    
106        private MessageQueueService getRouteQueueService() {
107            return KSBServiceLocator.getMessageQueueService();
108        }
109    
110    }