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| | |
| | | /* |
| | | * Copyright (C) 2013 The Android Open Source Project |
| | | * |
| | | * Licensed under the Apache License, Version 2.0 (the "License"); |
| | | * you may not use this file except in compliance with the License. |
| | | * You may obtain a copy of the License at |
| | | * |
| | | * http://www.apache.org/licenses/LICENSE-2.0 |
| | | * |
| | | * Unless required by applicable law or agreed to in writing, software |
| | | * distributed under the License is distributed on an "AS IS" BASIS, |
| | | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| | | * See the License for the specific language governing permissions and |
| | | * limitations under the License. |
| | | */ |
| | | package com.dayu.recharge.tools; |
| | | |
| | | import android.annotation.TargetApi; |
| | | import android.nfc.NfcAdapter; |
| | | import android.nfc.Tag; |
| | | import android.nfc.tech.IsoDep; |
| | | import android.os.Build; |
| | | import android.util.Log; |
| | | |
| | | |
| | | import java.io.IOException; |
| | | import java.lang.ref.WeakReference; |
| | | import java.util.Arrays; |
| | | |
| | | /** |
| | | * Callback class, invoked when an NFC card is scanned while the device is running in reader mode. |
| | | * <p> |
| | | * Reader mode can be invoked by calling NfcAdapter |
| | | */ |
| | | @TargetApi(Build.VERSION_CODES.KITKAT) |
| | | public class LoyaltyCardReader implements NfcAdapter.ReaderCallback { |
| | | private static final String TAG = "LoyaltyCardReader"; |
| | | // AID for our loyalty card service. |
| | | private static final String SAMPLE_LOYALTY_CARD_AID = "F0010203040507"; |
| | | // ISO-DEP command HEADER for selecting an AID. |
| | | // Format: [Class | Instruction | Parameter 1 | Parameter 2] |
| | | private static final String SELECT_APDU_HEADER = "00A40400"; |
| | | // "OK" status word sent in response to SELECT AID command (0x9000) |
| | | private static final byte[] SELECT_OK_SW = {(byte) 0x10, (byte) 0x00}; |
| | | |
| | | // Weak reference to prevent retain loop. mAccountCallback is responsible for exiting |
| | | // foreground mode before it becomes invalid (e.g. during onPause() or onStop()). |
| | | private WeakReference<AccountCallback> mAccountCallback; |
| | | |
| | | public interface AccountCallback { |
| | | public void onAccountReceived(Tag tag); |
| | | } |
| | | |
| | | public LoyaltyCardReader(AccountCallback accountCallback) { |
| | | mAccountCallback = new WeakReference<AccountCallback>(accountCallback); |
| | | } |
| | | |
| | | /** |
| | | * Callback when a new tag is discovered by the system. |
| | | * |
| | | * <p>Communication with the card should take place here. |
| | | * |
| | | * @param tag Discovered tag |
| | | */ |
| | | @Override |
| | | public void onTagDiscovered(Tag tag) { |
| | | Log.i(TAG, "New tag discovered"); |
| | | mAccountCallback.get().onAccountReceived(tag); |
| | | // Android's Host-based Card Emulation (HCE) feature implements the ISO-DEP (ISO 14443-4) |
| | | // protocol. |
| | | // |
| | | // In order to communicate with a device using HCE, the discovered tag should be processed |
| | | // using the IsoDep class. |
| | | IsoDep isoDep = IsoDep.get(tag); |
| | | if (isoDep != null) { |
| | | try { |
| | | // Connect to the remote NFC device |
| | | isoDep.connect(); |
| | | // Build SELECT AID command for our loyalty card service. |
| | | // This command tells the remote device which service we wish to communicate with. |
| | | Log.i(TAG, "Requesting remote AID: " + SAMPLE_LOYALTY_CARD_AID); |
| | | // mAccountCallback.get().onAccountReceived(); |
| | | byte[] command = BuildSelectApdu(SAMPLE_LOYALTY_CARD_AID); |
| | | |
| | | // Send command to remote device |
| | | Log.i(TAG, "Sending: " + ByteArrayToHexString(command)); |
| | | // mAccountCallback.get().onAccountReceived(); |
| | | byte[] result = isoDep.transceive(command); |
| | | // If AID is successfully selected, 0x9000 is returned as the status word (last 2 |
| | | // bytes of the result) by convention. Everything before the status word is |
| | | // optional payload, which is used here to hold the account number. |
| | | int resultLength = result.length; |
| | | byte[] statusWord = {result[resultLength - 2], result[resultLength - 1]}; |
| | | byte[] payload = Arrays.copyOf(result, resultLength - 2); |
| | | if (Arrays.equals(SELECT_OK_SW, statusWord)) { |
| | | // The remote NFC device will immediately respond with its stored account number |
| | | String accountNumber = new String(payload, "UTF-8"); |
| | | Log.i(TAG, "Received: " + accountNumber); |
| | | // Inform CardReaderFragment of received account number |
| | | // mAccountCallback.get().onAccountReceived(); |
| | | } |
| | | } catch (IOException e) { |
| | | Log.e(TAG, "Error communicating with card: " + e.toString()); |
| | | } |
| | | } |
| | | } |
| | | |
| | | /** |
| | | * Build APDU for SELECT AID command. This command indicates which service a reader is |
| | | * interested in communicating with. See ISO 7816-4. |
| | | * |
| | | * @param aid Application ID (AID) to select |
| | | * @return APDU for SELECT AID command |
| | | */ |
| | | public static byte[] BuildSelectApdu(String aid) { |
| | | // Format: [CLASS | INSTRUCTION | PARAMETER 1 | PARAMETER 2 | LENGTH | DATA] |
| | | return HexStringToByteArray(SELECT_APDU_HEADER + String.format("%02X", aid.length() / 2) + aid); |
| | | } |
| | | |
| | | /** |
| | | * Utility class to convert a byte array to a hexadecimal string. |
| | | * |
| | | * @param bytes Bytes to convert |
| | | * @return String, containing hexadecimal representation. |
| | | */ |
| | | public static String ByteArrayToHexString(byte[] bytes) { |
| | | final char[] hexArray = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; |
| | | char[] hexChars = new char[bytes.length * 2]; |
| | | int v; |
| | | for (int j = 0; j < bytes.length; j++) { |
| | | v = bytes[j] & 0xFF; |
| | | hexChars[j * 2] = hexArray[v >>> 4]; |
| | | hexChars[j * 2 + 1] = hexArray[v & 0x0F]; |
| | | } |
| | | return new String(hexChars); |
| | | } |
| | | |
| | | /** |
| | | * Utility class to convert a hexadecimal string to a byte string. |
| | | * |
| | | * <p>Behavior with input strings containing non-hexadecimal characters is undefined. |
| | | * |
| | | * @param s String containing hexadecimal characters to convert |
| | | * @return Byte array generated from input |
| | | */ |
| | | public static byte[] HexStringToByteArray(String s) { |
| | | int len = s.length(); |
| | | byte[] data = new byte[len / 2]; |
| | | for (int i = 0; i < len; i += 2) { |
| | | data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) |
| | | + Character.digit(s.charAt(i + 1), 16)); |
| | | } |
| | | return data; |
| | | } |
| | | |
| | | } |