[HOW-TO] Programmatically create and cancel Timers

[sonicfab]

I spent some time on finding out how to programmatically create and cancel timers, so I thought it might be a good idea to share this with you.
(Note : this works with jBPM-jPDL 3.2.1 and 3.2.2).

1- Define a scheduler service in jbpm.cfg.xml :

<service name="scheduler"
 factory="org.jbpm.scheduler.db.DbSchedulerServiceFactory" />

2- Start a job executor thread (we do it via Spring) :

<!-- Jbpm job executor -->
 <bean name="jbpm.job.executor" class="org.jbpm.job.executor.JobExecutor">
 <field name="jbpmConfiguration"><ref bean="jbpmConfiguration" /></field>
 <field name="name"><string value="JbpmJobExector" /></field>
 <field name="nbrOfThreads"><int value="1" /></field>
 <field name="idleInterval"><int value="5000" /></field>
 <field name="maxIdleInterval"><int value="3600000" /></field> <!-- 1 hour -->
 <field name="historyMaxSize"><int value="20" /></field>
 <field name="maxLockTime"><int value="600000" /></field> <!-- 10 minutes -->
 <field name="lockMonitorInterval"><int value="60000" /></field> <!-- 1 minute -->
 <field name="lockBufferTime"><int value="5000" /></field> <!-- 5 seconds -->
 </bean>

The job executor is instantiated by a Spring listener :

<!-- Bean responsible for starting and stopping the JBPM JobExecutor -->
 <bean id="jbpmLifeCycleListener"
 class="com.acme.jbpm.helpers.JbpmLifeCycleListener"
 init-method="start" destroy-method="stop">
 <property name="configuration" value="classpath:jbpm.cfg.xml" />
 <property name="sessionFactory" ref="jbpmSessionFactory" />
 </bean>

3- Create a timer :

public static void createNotificationTimer(ExecutionContext context,
 Date dueDate, String timerName, String nodeName) {

 try {
 // getting data from the context
 long processId = context.getProcessInstance().getId();
 Token token = context.getToken();
 String orderOrigin = (String) context
 .getVariable(ContextVariable.orderOrigin);
 String externalOrderId = (String) context
 .getVariable(ContextVariable.externalOrderId);
 Node myNode = context.getProcessDefinition().getNode(nodeName);

 // creating the action
 Action timedAction = new Action();
 Delegation timedDelegation = new Delegation(
 "com.acme.businesslayer.jbpm.timers.NotificationAction");
 timedDelegation
 .setConfiguration(String
 .format("<tokenId>%d</tokenId><externalOrderId>%s</externalOrderId><orderOrigin>%s</orderOrigin>",
 token.getId(), externalOrderId, orderOrigin));
 timedAction.setActionDelegation(timedDelegation);

 // creating the timer
 Timer timer = new Timer(token);
 String completeTimerName = String.format("%s-%d", timerName,
 processId);
 timer.setName(completeTimerName);
 timer.setAction(timedAction);
 timer.setDueDate(dueDate);

 // setting the execution context
 context.setTimer(timer);

 // scheduling the timer
 myNode.fireEvent("timer-create", context);
 JbpmConfiguration conf = (JbpmConfiguration) SpringHelper
 .getBean("jbpmConfiguration");
 JbpmContext myContext = conf.createJbpmContext();
 myContext.setSessionFactory((SessionFactory) SpringHelper
 .getBean("jbpmSessionFactory"));
 SchedulerService schedulerService = (SchedulerService) myContext.getServices().getService(Services.SERVICENAME_SCHEDULER);
 SchedulerService.createTimer(timer);
 myContext.close();

 } catch (Exception e) {
 e.printStackTrace();
 }
 }

4- Cancel a timer :

public static void cancelTimer(String timerName, Token token) {
 JbpmConfiguration conf = (JbpmConfiguration) SpringHelper
 .getBean("jbpmConfiguration");
 JbpmContext testContext = conf.createJbpmContext();
 myContext.setSessionFactory((SessionFactory) SpringHelper
 .getBean("jbpmSessionFactory"));

 SchedulerService schedulerService = (SchedulerService) myContext.getServices().getService(Services.SERVICENAME_SCHEDULER);
 String completeTimerName = String.format("%s-%d", timerName, token.getProcessInstance().getId());
 schedulerService.deleteTimersByName(completeTimerName, token);
 myContext.close();
 }

Hope this will help save time for some of you.

[dejan]

Hi Fabian,
could you also paste the code from JbpmLifeCycleListener class?

Thanks,
Dejan

[sonicfab]

Ok here it is below.
(Maybe I should start a blog ;-), or independent paid consultancy ;-)) )

public class JbpmLifeCycleListener {

 /** Keylogger. */
 private static KeyLogger keyLogger = KeyLoggerFactory.getLogger(JbpmLifeCycleListener.class);

 /** Jbpm configuration */
 private JbpmConfiguration _jbpmConfiguration;

 /** Resource. */
 private Resource configuration;

 /** SessionFactory */
 private SessionFactory sessionFactory;

 /** Set the configuration file resource. */
 @Required
 public void setConfiguration(Resource configuration) {
 this.configuration = configuration;
 }

 /** Set the hibernate session factory. */
 @Required
 public void setSessionFactory(SessionFactory sessionFactory) {
 this.sessionFactory = sessionFactory;
 }

 /**
 * Performs work after creation of JbpmConfiguration.
 */
 public void start() {
 initJBPMConfiguration();
 if (null != _jbpmConfiguration) {
 afterCreation(_jbpmConfiguration);
 }
 }

 /**
 * Initialize the {@link JbpmConfiguration}
 *
 */
 public void initJBPMConfiguration() {
 if (null == _jbpmConfiguration) {
 try {
 _jbpmConfiguration = JbpmConfiguration.parseInputStream(configuration.getInputStream());
 JbpmContext jbpmContext = _jbpmConfiguration.createJbpmContext();
 ServiceFactory svF = _jbpmConfiguration.getServiceFactory(Services.SERVICENAME_PERSISTENCE);

 // Configure it to start its own transaction and open hibernate session
 DbPersistenceServiceFactory dbF = (DbPersistenceServiceFactory)svF;
 dbF.setTransactionEnabled(true);
 dbF.setCurrentSessionEnabled(false);
 try {
 jbpmContext.setSessionFactory(sessionFactory);
 }

 finally {
 if (null != jbpmContext) jbpmContext.close();
 }
 } catch (IOException e) {
 keyLogger.log(DefaultLogKeyMessageConstants.GENERIC_ERROR_MESSAGE, new String[]{"Unable" +
 "to retrieve JBPMConfiguration"});
 }
 }

 }

 /**
 * Performs work before destruction JbpmConfiguration.
 */
 public void stop() {
 initJBPMConfiguration();
 if (null != _jbpmConfiguration) {
 beforeDestroy(_jbpmConfiguration);
 }
 }

 /**
 * Called after creation of the jbpm configuration to perform additional tasks.
 * @param configuration jbpmConfiguration
 */
 public void afterCreation(JbpmConfiguration configuration) {
 keyLogger.debug("Starting job executor...");
 configuration.startJobExecutor();
 keyLogger.debug("Job executor started.");
 }

 /**
 * Called before destruction of the jbpm configuration.
 * @param configuration
 */
 public void beforeDestroy(JbpmConfiguration configuration) {
 keyLogger.debug("Stopping job executor...");
 configuration.getJobExecutor().stop();
 keyLogger.debug("Job executor stopped.");
 }

}

[dejan]

Thanks.
However, I already found another solution that better suited my needs. http://www.jboss.com/index.html?module=bb&op=viewtopic&t=119652
Anyway, I am sure your code will help other people. I know that I had hard time trying to configure Jbpm executor with Spring.

[kukeltje]

There is a jBPM wiki where you can add these kinds of things... feel free