Java Message Service, 2nd Edition

Lost Connections

When the network connection between the client and server is lost, a JMS provider must make every reasonable attempt to reestablish the connection. In the event that the JMS provider cannot automatically reconnect, the provider must notify the client of this condition by throwing an exception when the client invokes a method that would cause network traffic to occur. However, it is reasonable to expect that a JMS client may only be a receiver using the MessageListener interface, and not a producer that makes any outbound publish() or send() calls. In this case, the client is not invoking JMS methods—it is just listening for messages—so a dropped connection may not be detected.

JMS provides an ExceptionListener interface for trapping a lost connection and notifying the client of this condition. The ExceptionListener is bound to the connection—unlike MessageListeners, which are bound to sessions. The definition of the ExceptionListener is:

public interface ExceptionListener {
   void onException(JMSException exception);
}

It is the responsibility of the JMS provider to call the onException() method of all registered ExceptionListeners after making reasonable attempts to reestablish the connection automatically. The JMS client can implement the ExceptionListener so that it can be alerted to a lost connection and possibly attempt to reestablish the connection manually.

How can the JMS provider call an ExceptionListener if the client has been disconnected? Every JMS provider ...