FAQ-0715 In JTAPI I don't receive the connectionCreated events I am expecting. Why not?


FAQ-0715 In JTAPI I don't receive the connectionCreated events I am expecting. Why not?

» Symbian OS » Developer Knowledgebase » FAQ-0715

Classification:	Java	Category:	JavaPhone
Created:	07/16/2001	Modified:	09/11/2002
Number:	FAQ-0715
Platform:	Symbian OS v6.0

Question:
I have associated a ConnectionListener with my local Terminal using the Terminal.addCallListener(...) method. I'd expect each call to result in two connectionCreated events but I only get one in the case of incoming calls and none in the case of outgoing calls. Is this a defect? What can I do about it?

Answer:
This problem is a result of inconsistency/ambiguity in the JTAPI spec. When you associate a CallListener with your local Terminal, you will only pick up connectionCreated events for Connection objects which are associated with the local Terminal. But this can only occur through a TerminalConnection being brought into existence linking the Connection object and the local Terminal. And the semantics of the JTAPI object model require that the Connection object must be created before any linked TerminalConnection. So logically a ConnectionListener on a local Terminal can never detect local connectionCreated events.

It is an incidental detail of the Symbian JTAPI implementation that remote Connection ojects are created earlier for incoming than for outgoing calls. As a result, remote connectionCreated events are picked by a ConnectionListener on the local Terminal in the former but not the latter case. The behaviour for outgoing calls will be changed in v6.1 to bring it into conformance with that for incoming calls, i.e. generating a single connectionCreated event. But this remains an implementation detail and should not be relied upon. The recommended work around for this problem is to listen instead for terminalConnectionCreated events with a TerminalConnectionListener. Exactly two of these events are guaranteed to be received by a listener on the local Terminal, for each incoming or outgoing call which is handled.