How can I do the offline transactions

[Thelogan]

I am working on applet development for online payment. Now I am experiencing a problem about how to store the offline data into java card.
How can I do the offline transactions? Hope somebody provide me more points. thx

[horse dream]

You should store the offline balance in the persistent memory. Moreover, updates to this persistent memory must be atomic.
That is if a transaction is going on and there is a card tear, then the transaction should be invalid.
For this, Java Card has the beginTransaction and abortTransaction methods in JCSystem.