Listening and Launching

Listening and Launching

The Application Management Software (AMS) listens for registered connections and manages the launch of and transition to the appropriate MIDlet. It and the other software on the device provide a seamless integration of native and MIDP applications. The AMS handles the interactions among incoming connections, interrupting the user, starting and stopping applications, and handing off connections to MIDlets. It also enforces the device's security policy and constraints.

For example, if a native application is running when a notification arrives, the AMS must interrupt it. It must give the user control over the interruption (for example, user settings determine whether the interruption is to launch the new MIDlet or to get permission to launch it) and any transition to the MIDlet that responds to the network event. To make the transition, the AMS stops or pauses the running application. It and the other software on the device must work together to make the consumer experience smooth and natural.

The AMS would do similar things if a MIDlet was running when a notification arrives. It would call either the pauseApp method or the destroyApp method to change to the MIDlet that responds to the connection. The MIDlet life cycle defines the duties of the interrupted MIDlet. (Refer to "MIDlet States" on page 82.)

The implementation handles incoming connections in a way that allows them to be held and passed on to the MIDlet when it is started. The requirements for buffering of connections and messages are protocol-specific. There is a general requirement, though, that if a device buffers data, it must provide the buffered information to the MIDlet. The device should supply any buffered data when the launched MIDlet opens the related connection.

When a device supports datagram connections for push notification, it must buffer at least the datagram that caused the startup of the MIDlet. It must also guarantee that when it starts a MIDlet in response to the incoming datagram, the buffered data will be available to the MIDlet when the MIDlet opens the UDPDatagramConnection.

The requirement for devices that support socket connections for push notification is different. The device must guarantee that when it starts a MIDlet in response to an incoming socket connection, the MIDlet can accept the connection by opening the ServerSocketConnection, provided that the connection has not timed out.