How to Understand Java API Usage for Contactless CPU Cards

Overview

This section provides a step-by-step guide on using the Java API for interacting with contactless CPU cards.

Steps for Java API Usage

• Get RFCardReaderDevice:

Retrieve the instance of the RFCardReaderDevice to initiate communication with the contactless card reader.

  device = (RFCardReaderDevice) POSTerminal.getInstance(mContext).getDevice(POSTerminal.DEVICE_NAME_RF_CARD_READER);

• Open Device:

Execute the command to open the card reader device. This step establishes a connection between the Java application and the card reader.

  device.open();

• Search for Card:

Initiate a search for the contactless CPU card. This involves scanning for available cards within the reader's range.

  OperationListener listener = new OperationListener() {
    @Override
    public void handleResult(OperationResult arg0) {
      if (arg0.getResultCode() == OperationResult.SUCCESS) {
        sendSuccessLog2(mContext.getString(R.string.find_card_succeed));
        rfCard = ((RFCardReaderOperationResult) arg0).getCard();
      } else {
        sendFailedLog2(mContext.getString(R.string.find_card_failed));
      }
    }
  };
  device.listenForCardPresent(listener, TimeConstants.FOREVER); The result will be returned in the callback listener.

• Communicate with Card:

Once the card is detected, establish communication. This step may involve reading from or writing to the card, depending on the application's requirements.

  
  if (rfCard instanceof CPUCard) {
    CPUCard cpucard = ((CPUCard) rfCard);
    ATR atr = cpucard .connect();
    result = cpucard .transmit(arryAPDU, 0);
    cpucard .disconnect();
  }

• Close Device:

After the communication with the card is complete, close the device to end the session. This step is crucial for maintaining device security and integrity.

  device.close();

Important Notes

• Each step should be performed in sequence to ensure successful communication with the contactless CPU card.
• Handle exceptions and errors appropriately to maintain the stability of your application.