6131 NFC: notify midlet after javacard access

[cde]

Hi,

I have a wallet on the javacard of my 6131 NFC. A J2ME midlet reads the balance and displays it. You can also access the javacard-wallet from a desktop reader und decrement/increment the balance.

Is it possible to notify the running J2ME midlet if the desktop reader changes the credit on the javacard?

Regards
Andi

[tsavinen]

Use the DiscoveryManager.addTransactionListener() method to receive
TransactionListener.externalReaderDetected() notifications.

[cde]

OK, that's possible. But how do i know that the data has changed? It can be immediately after detecting a reader or a few seconds later. Is there any other change to get an event?

Regards
Andi

[tsavinen]

I don't think there is a way to know if something changed.
It's just possible that something has happened when you get the event.
Below is the part of the javadoc that explains the same thing.

--clip--
void externalReaderDetected(byte slot)

Called by the platform, when a card emulation event has happened on the RFID hardware. This notification informs the application, that there might be changes in the data on the secure element.

If the application displays for example the number of metro tickets left in the device, after receiving this notification the application can update the number of available tickets shown on the screen. How the number of tickets is acquired from the secure element is out of scope for this specification.
--clap--

[cde]

Thank you for the information! I try to use the readerDetected event in my midlet.

Regards
Andi

[jlanza]

Hi,

I have a wallet on the javacard of my 6131 NFC. A J2ME midlet reads the balance and displays it. You can also access the javacard-wallet from a desktop reader und decrement/increment the balance.

How do you read it from the Desktop? What kind of connection are you using to read from the mobile card?

[esunilkumare]

hi jlanza,

you can read the cardlet info from the desktop reader using JCOP offcard API.

please go thru the following link.

http://forum.java.sun.com/thread.jsp...hreadID=702955

it is not the proper program to do ur purpose. but you can go thru the JCOP Offcard documentation for further help.

Sunil