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.camel.bam.processor;
018
019 import java.util.Date;
020 import java.util.HashMap;
021 import java.util.List;
022 import java.util.Map;
023 import javax.persistence.EntityManager;
024 import javax.persistence.LockModeType;
025 import javax.persistence.PersistenceException;
026
027 import org.apache.camel.bam.QueryUtils;
028 import org.apache.camel.bam.model.ActivityState;
029 import org.apache.camel.bam.rules.ProcessRules;
030 import org.apache.camel.impl.ServiceSupport;
031 import org.apache.camel.util.CastUtils;
032 import org.apache.commons.logging.Log;
033 import org.apache.commons.logging.LogFactory;
034 import org.springframework.orm.jpa.JpaCallback;
035 import org.springframework.orm.jpa.JpaTemplate;
036 import org.springframework.transaction.TransactionStatus;
037 import org.springframework.transaction.support.TransactionCallbackWithoutResult;
038 import org.springframework.transaction.support.TransactionTemplate;
039 import org.springframework.util.ClassUtils;
040
041 /**
042 * A timer engine to monitor for expired activities and perform whatever actions
043 * are required.
044 *
045 * @version $Revision: 17033 $
046 */
047 public class ActivityMonitorEngine extends ServiceSupport implements Runnable {
048 private static final Log LOG = LogFactory.getLog(ActivityMonitorEngine.class);
049 private JpaTemplate template;
050 private TransactionTemplate transactionTemplate;
051 private ProcessRules rules;
052 private long windowMillis = 1000L;
053 private Thread thread;
054 private boolean useLocking;
055
056 public ActivityMonitorEngine(JpaTemplate template, TransactionTemplate transactionTemplate, ProcessRules rules) {
057 this.template = template;
058 this.transactionTemplate = transactionTemplate;
059 this.rules = rules;
060 }
061
062 public boolean isUseLocking() {
063 return useLocking;
064 }
065
066 public void setUseLocking(boolean useLocking) {
067 this.useLocking = useLocking;
068 }
069
070 public void run() {
071 LOG.debug("Starting to poll for timeout events");
072
073 while (!isStopped()) {
074 try {
075 long now = System.currentTimeMillis();
076 long nextPoll = now + windowMillis;
077 final Date timeNow = new Date(now);
078
079 transactionTemplate.execute(new TransactionCallbackWithoutResult() {
080 protected void doInTransactionWithoutResult(TransactionStatus status) {
081 Map<String, Object> params = new HashMap<String, Object>(1);
082 params.put("timeNow", timeNow);
083
084 List<ActivityState> list = CastUtils.cast(template.findByNamedParams("select x from "
085 + QueryUtils.getTypeName(ActivityState.class) + " x where x.timeOverdue < :timeNow", params));
086 for (ActivityState activityState : list) {
087 fireExpiredEvent(activityState);
088 }
089 }
090 });
091
092 long timeToSleep = nextPoll - System.currentTimeMillis();
093 if (timeToSleep > 0) {
094 if (LOG.isDebugEnabled()) {
095 LOG.debug("Sleeping for " + timeToSleep + " millis");
096 }
097 try {
098 Thread.sleep(timeToSleep);
099 } catch (InterruptedException e) {
100 LOG.debug("Caught: " + e, e);
101 }
102 }
103 } catch (Exception e) {
104 LOG.error("Caught: " + e, e);
105 }
106 }
107 }
108
109 protected void fireExpiredEvent(final ActivityState activityState) {
110 if (LOG.isDebugEnabled()) {
111 LOG.debug("Trying to fire expiration of: " + activityState);
112 }
113
114 template.execute(new JpaCallback() {
115 public Object doInJpa(EntityManager entityManager) throws PersistenceException {
116 // lets try lock the object first
117 if (isUseLocking()) {
118 LOG.info("Attempting to lock: " + activityState);
119 entityManager.lock(activityState, LockModeType.WRITE);
120 LOG.info("Grabbed lock: " + activityState);
121 }
122
123 try {
124 rules.processExpired(activityState);
125 } catch (Exception e) {
126 LOG.error("Failed to process expiration of: " + activityState + ". Reason: " + e, e);
127 }
128 activityState.setTimeOverdue(null);
129 //activityState.setEscalationLevel(escalateLevel + 1);
130 return null;
131 }
132 });
133 }
134
135 protected void doStart() throws Exception {
136 rules.start();
137 thread = new Thread(this, "ActivityMonitorEngine");
138 thread.start();
139 }
140
141 protected void doStop() throws Exception {
142 if (thread != null) {
143 thread = null;
144 }
145 rules.stop();
146 }
147 }