File	Doc	Category	Size	Date	Package
JavaLoyalty.java	API Doc	Java Card	5791	Wed Mar 22 21:07:26 GMT 2006	package com.sun.javacard.samples.JavaLoyalty

JavaLoyalty

• java.lang.Object
  • Applet

Fields Summary
static final byte	READ_BALANCE
static final byte	RESET_BALANCE
static final byte	CREDIT
static final byte	DEBIT
static final short	TRANSACTION_TYPE_OFFSET
static final short	TRANSACTION_AMOUNT_OFFSET
static final short	SCALE
static final short	BALANCE_MAX
short	balance

Constructors Summary

protected JavaLoyalty(byte[] bArray, short bOffset, byte bLength) Performs memory allocations, initializations, and applet registration param bArray received by install. param bOffset received by install. param bLength received by install. balance = (short)0; /* * if AID length is not zero register Java Loyalty * applet with specified AID * * NOTE: all the memory allocations should be performed before register() */ byte aidLen = bArray[bOffset]; if (aidLen== (byte)0){ register(); } else { register(bArray, (short)(bOffset+1), aidLen); }

Methods Summary
public Shareable	getShareableInterfaceObject(AID clientAID, byte parameter) Implements getShareableInterfaceObject method of Applet class. JavaLoyalty could check here if the clientAID is that of JavaPurse Checking of the parameter to be agreed upon value provides additional security, or, if the Shareable Interface Object weren't JavaLoyalty itself it could return different Shareable Interface Objects for different values of clientAID and/or parameter. SeeJava Card Runtime Environment (JCRE) Specification for details. param clientAID AID of the client param parameter additional parameter return JavaLoyalty object if (parameter == (byte)0) return this; else return null;
public void	grantPoints(byte[] buffer) Implements main interaction with a client. The data is transfered through APDU buffer which is a global array accessible from any context. The format of data in the buffer is subset of Transaction Log record format: 2 bytes of 0, 1 byte of transaction type, 2 bytes amount of transaction, 4 bytes of CAD ID, 3 bytes of date, and 2 bytes of time. This sample implementation ignores everything but transaction type and amount. param buffer APDU buffer short amount = Util.getShort(buffer, TRANSACTION_AMOUNT_OFFSET); amount = (short) (amount / SCALE); switch (buffer[TRANSACTION_TYPE_OFFSET]) { case DEBIT: balance = (short)(balance + amount); break; case CREDIT: balance = (short) (balance - amount); break; } if (balance < 0) balance = 0; if (balance > BALANCE_MAX) balance = BALANCE_MAX; /* * For this simple sample applet we don't keep track of transaction locations and * timestamps */
public static void	install(byte[] bArray, short bOffset, byte bLength) Installs Java Loyalty applet. param bArray install parameter array. param bOffset where install data begins. param bLength install parameter data length. new JavaLoyalty(bArray, bOffset, bLength);
public void	process(APDU apdu) Dispatches APDU commands. param apdu APDU byte[] buffer = apdu.getBuffer(); // We don't do any additional C-APDU header checking, just rely on // CLA and INS bytes for dispatching. if (apdu.isISOInterindustryCLA()) { if (buffer[ISO7816.OFFSET_INS] == (byte)(0xA4)) { return; } else { ISOException.throwIt (ISO7816.SW_CLA_NOT_SUPPORTED); } } switch (buffer[ISO7816.OFFSET_INS]) { case READ_BALANCE: processReadBalance(apdu); break; case RESET_BALANCE: processResetBalance(); break; default: ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED); }
void	processReadBalance(APDU apdu) Sends 2 bytes of balance value in R-APDU. param apdu APDU byte[] buffer = apdu.getBuffer(); Util.setShort(buffer, (short)0, balance); apdu.setOutgoingAndSend((short)0, (short)2);
void	processResetBalance() Resets Balance. balance = (short)0;