Store array of objects in Java Card 2.2.1 platform

Question

Hi all,
I am new to smart card development and developing a demo e-wallet application using Java Card 2.2.1 SDK. I'd like to store last 10 transactions in card and create getter-setter methods. The structure of Transaction that i thought as follow:
public class Transaction {
     private byte type; // + or -
     private short amount;
     private byte[] date;
[Date format: "yyyy-MM-dd HH:mm:ss"]And transactionList:
public class TransactionList {
     protected short currentIndex = (short) -1;
     protected Transaction [] list = new Transaction [10];
}In my desktop application i have already called card's selectApplication(); / getBalance(); / setBalance(); / getWalletId(); / setWalletId(); methods. I need to create a method [getLastTransactions] in card project and call it from my desktop application.
<font size="2">How should I set up a structure for this issue?</font>

Answer 1

First of all don't allocate memory other than the constructor.
As you know you cannot return an object as a response from a java card so what you will get is just bytes of data. So create a byte[] of size equal to LAST_10_TRANSTION_SIZE and then by TLV store data into that array and upon receiving on host side decode it using the TLV.