ex8_17.txt

j2ee core design patterns

Example 8.17 	MDB Service Activator, OrderServiceActivatorMDB.java
public class OrderServiceActivator
		implements javax.ejb.MessageDrivenBean,
		javax.jms.MessageListener {
	. . .

	// The EJB container will invoke onMessage when a message 
	// arrives for this Service Activator
	public void onMessage(Message message) {
		try {
			// parse Message msg. See JMS API for Message.
			// Get the order object from the message
			ObjectMessage objectMessage =
					(javax.jms.ObjectMessage) message;
			Order order = (Order)objectMessage.getObject();

			// Use the Business Delegate for Order Processor
			// Session Fa鏰de to invoke order processing
			OrderProcessorDelegate orderProcessorBD =
					new OrderProcessorDelegate();
			orderProcessorBD.processOrder(order);

			// send any response here...
		}
		catch (JMSException jmsexcp) {
			// Handle JMSExceptions, if any
			// Send error response, throw runtime exception
		} 
		catch (Exception excp) {
			// Handle any other exceptions
			// Send error response, throw runtime exception
		}
	}

	// implement other methods required by the
	// Message Driven Bean
	public void setMessageDrivenContext(
			javax.ejb.MessageDrivenContext ctx)
			throws javax.ejb.EJBException { . . . }

	public void ejbCreate() { . . . }

	public void ejbRemove() { . . . }
}