0

I am new Java card development and I want to know how to handle transactions when power is lost during a transaction. I want to know is there way to reset internally when power is lost or remove java card from card terminal. In my Java card applet I unsuccessfully tried:

  • JCSystem.beginTransaction();
  • JCSystem.commitTransaction();
  • Util.arrayCopyNonAtomic();

Is there any other way to do it?

Thanks Sajith

Chilledrat
  • 2,593
  • 3
  • 28
  • 38
Sajith Vijesekara
  • 1,324
  • 2
  • 17
  • 52
  • 1
    How is it not working? And are you sure you want to use `arrayCopyNonAtomic` within a transaction (doesn't it defeat the purpose of that transaction)? – martijno Aug 24 '13 at 20:26
  • 1
    You are creating a lot of (valid) questions that are perfectly explained in the venerable book [Java Card Technology for Smart Cards](http://books.google.nl/books/about/Java_Card_Technology_for_Smart_Cards.html?id=4WDj4H6pT50C&redir_esc=y) – Maarten Bodewes Aug 25 '13 at 17:33

1 Answers1

1

Within transactions writes to persistent memory such as EEPROM or flash are handled atomically. That is: as if all the writes to persistent memory are part of one big action.

To create an atomic copy you need to use Util.arrayCopy() instead of Util.arrayCopyNonAtomic(). There may also be other actions that can take part of atomicity. If actions that change persistent memory do not take part in an atomic transaction then the Java Card API will explicitly document those actions.

As indicated before, there is no method to reset a Java Card. Instead you can use JCSystem.abortTransaction().

Maarten Bodewes
  • 90,524
  • 13
  • 150
  • 263