Provides a notification API for the MQ client runtime to inform an application about a MQ connection state changes.

The current notification types defined for the MQ 4.0 release are as follows:

- Connection closing event. A connection closing event is generated and delivered to the event listener if the broker is about to close a MQ connection (such as admin requested shutdown) and an event listener is set to the MQ connection.
- Connection closed event. A connection closed event is generated and delivered to the event listener if the broker closed a MQ connection (such as admin requested shutdown, restart, out of memory, etc.) and an event listener is set to the MQ connection.
- Connection reconnected event. A connection reconnected event is generated and delivered to the event listener if the MQ client runtime reconnected to a broker and an event listener is set to the MQ connection.
- Connection reconnect failed event. A connection reconnect failed event is generated and delivered to the event listener if a reconnect attempt to a broker failed and an event listener is set to the MQ connection. (MQ client runtime will retry base on the reconnect contract).

A MQ application sets a connection event listener in order to be notified for the MQ events. The API to set the notification listener is defined in the `com.sun.messaging.jms.Connection` class.

@see com.sun.messaging.jms