EJB-消息驱动的Bean配置

Question

I have two message driven beans in my project. Which one will be called by ejb container when a message is sent to queue. Where is it configured which bean to invoke. What is use of ejb-jar.xml and ibm-ejb-jar-bnd. Xml. Please explain

Answer 1

A Message driven bean (MDB) is associated with a JMS queue (or topic) through deployment descriptors or Java annotations. The simplest form as from EE7 is with the use of annotations as follows:

@MessageDriven(mappedName = "myQueue")

public class MyMDB implements MessageListener {

@Override public void onMessage(Message message) {

....

The mappedName attribute specifies the JNDI name of the JMS destination of the queue.

Answer 2

如果您有两个由同一队列驱动的MDB，则只有一个MDB将处理任何给定的消息，并且您无法事先知道它将是哪个MDB。