connection.setExceptionListener((e) -> {
   connection = cf.createConnection();
   session = connection.createSession();
   consumer = session.createConsumer(session.createQueue("FANCY.QUEUE.NAME"));
   consumer.setMessageListener((m) -> {
     System.out.println("onMessage: " + m);
   }
   connection.start();
 });

@RequiredArgsConstructor
static class ReconnectingListener implements MessageListener,  ExceptionListener {
    final JmsConnectionFactory cf;
    final String destinationQueue;
    
    private Connection connection;
    private Session session;
    private MessageConsumer consumer;
    // 1. Have a separate connect method
    public synchronized void connect() throws JMSException {
        // 2. Store the user desire if we should be connected or not
        shouldRun.set(true);
        if (!isConnected()) {
            connection = cf.createConnection();
            session = connection.createSession();
            consumer = session.createConsumer(session.createQueue(destinationQueue));
            consumer.setMessageListener(this); // register us
            connection.setExceptionListener(this); // react on errors
            connection.start();
        }
    }
    // 3. Have a separate disconnect method 
    public synchronized void disconnect() {
        // 2. Store the user desire if we should be connected or not
        shouldRun.set(false);
        clearConnection();
    }
    // 4. Have a way to clear the resources without to reset the user desire
    private synchronized void clearConnection() {
        JmsUtil.close(consumer);
        JmsUtil.close(session);
        JmsUtil.close(connection);
        consumer = null;
        session = null;
        connection = null;
        LOG.debug("Connection cleared and stoped");
   }
   // 5. Have a way to check if the connection is up and running
   public boolean isConnected() {
       return connection != null && consumer != null && session != null;
   }

// we need a executer to delay a retry attempt
private final ScheduledExecutorService reconnectScheduler = Executors.newScheduledThreadPool(1);
@Override
public void onException(JMSException exception) {
    // 1. Clear the old connection to avoid a double registration
    clearConnection();
    // 2. Schedule a delayed retry to connect again
    reconnect(5);
}
private void reconnect(final int delay) {            
    reconnectScheduler.schedule(() -> {
        // 3. Check if we still should be connected
        if (shouldRun.get()) {
            try {
                // here we use our connect method from above
                connect();
            } catch (Exception e) {
                // 4. Retry again, if we fail in our retry to connect to the broker
                LOG.info("Reconnect failed, will retry in {}s. {}", delay, e.getMessage());
                clearConnection(); // just for savety
                reconnect(delay);
            }
        }
    }, delay, TimeUnit.SECONDS);
}

public synchronized void connectJms2() throws JMSException {
    shouldRun.set(true);
    if (!isConnected()) {
        context = cf.createContext();
        context.setExceptionListener(this);
        context.setAutoStart(true);
        consumer = context.createConsumer(context.createQueue(destinationQueue));
        consumer.setMessageListener(this); // register us
    }
}

<!-- activiti --> 
<dependency> 
  <groupId>org.activiti</groupId> 
  <artifactId>activiti-engine</artifactId> 
  <version>6.0.0</version> 
</dependency> 
<dependency> 
  <groupId>org.activiti</groupId> 
  <artifactId>activiti-cdi</artifactId> 
  <version>6.0.0</version> 
</dependency> 
<!-- to get org.springframework.jndi.JndiObjectFactoryBean, same version as used by activiti --> 
<dependency> 
  <groupId>org.springframework</groupId> 
  <artifactId>spring-context</artifactId> 
  <version>4.2.5.RELEASE</version> 
</dependency> 
<!-- Needed to see the log --> 
<dependency> 
  <groupId>org.slf4j</groupId> 
  <artifactId>slf4j-log4j12</artifactId> 
  <version>${slf4j.version}</version> 
</dependency>

<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd"> 
<log4j:configuration debug="true" xmlns:log4j='http://jakarta.apache.org/log4j/'> 
  <appender name="console" class="org.apache.log4j.ConsoleAppender"> 
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" /> 
    </layout> 
  </appender> 
  <root> 
    <level value="INFO" /> <appender-ref ref="console" /> 
  </root> 
</log4j:configuration>

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> 
  <!-- lookup the JTA-Transaction manager --> 
  <bean id="transactionManager" class="org.springframework.jndi.JndiObjectFactoryBean"> 
    <property name="jndiName" value="java:appserver/TransactionManager" /> 
    <property name="resourceRef" value="true" /> 
  </bean> 
  <!-- using the JEE container thread factory for the managed executor service --> 
  <bean id="asyncExecutor" class="org.activiti.engine.impl.asyncexecutor.ManagedAsyncJobExecutor"> 
    <property name="threadFactory"> 
      <bean class="org.springframework.jndi.JndiObjectFactoryBean"> 
        <property name="jndiName" value="java:comp/DefaultManagedThreadFactory" /> 
        <property name="resourceRef" value="true" /> 
      </bean> 
    </property> 
  </bean> 
  <!-- process engine configuration --> 
  <bean id="processEngineConfiguration" class="org.activiti.cdi.CdiJtaProcessEngineConfiguration"> 
    <property name="dataSourceJndiName" value="jdbc/postgresql" /> 
    <property name="transactionManager" ref="transactionManager" /> 
    <property name="asyncExecutor" ref="asyncExecutor" /> 
    <!-- using externally managed transactions --> 
    <property name="transactionsExternallyManaged" value="true" /> 
    <!-- will create the activiti DB schema automatically as needed --> 
    <property name="databaseSchemaUpdate" value="true" /> 
  </bean> 
</beans>

@Singleton
@Startup
public class SampleProcessDeployerBA {

    @Inject RepositoryService repositoryService;

    @PostConstruct
    void start() {
        // this will deploy the same process over and over again ...
        Deployment deploy = repositoryService.createDeployment()
                .name("SampleProcess")
                .key("SampleProcess") // note this has no effect, the ID of the bpmn file is used "myProcess"
                .addClasspathResource("org/sterl/jee/activiti/impl/sample/control/SampleProcess.bpmn")
                .deploy();
        System.out.println("Deployed process ID: " + deploy.getId() + " KEY " + deploy.getKey());
    }
}

@Named // that activiti finds this EJB
@Singleton // show that this is a singleton
public class HelloWorldBF {
    @Inject RuntimeService runtimeService;

    public void startProcess() {
        // use here the id you defined in the process designer
        ProcessInstance process = runtimeService.startProcessInstanceByKey("myProcess");
        System.out.println("Process " + process.getName() + " started with ID: " + process.getId());
    }
}