| /* |
| * Copyright (C) 2010 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 android.nfc.tech; |
| |
| import android.nfc.ErrorCodes; |
| import android.nfc.Tag; |
| import android.os.Bundle; |
| import android.os.RemoteException; |
| import android.util.Log; |
| |
| import java.io.IOException; |
| |
| /** |
| * Provides access to NFC-A (ISO 14443-3A) properties and I/O operations on a {@link Tag}. |
| * |
| * <p>Acquire a {@link NfcA} object using {@link #get}. |
| * <p>The primary NFC-A I/O operation is {@link #transceive}. Applications must |
| * implement their own protocol stack on top of {@link #transceive}. |
| * |
| * <p class="note"><strong>Note:</strong> Methods that perform I/O operations |
| * require the {@link android.Manifest.permission#NFC} permission. |
| */ |
| public final class NfcA extends BasicTagTechnology { |
| private static final String TAG = "NFC"; |
| |
| /** @hide */ |
| public static final String EXTRA_SAK = "sak"; |
| /** @hide */ |
| public static final String EXTRA_ATQA = "atqa"; |
| |
| private short mSak; |
| private byte[] mAtqa; |
| |
| /** |
| * Get an instance of {@link NfcA} for the given tag. |
| * <p>Returns null if {@link NfcA} was not enumerated in {@link Tag#getTechList}. |
| * This indicates the tag does not support NFC-A. |
| * <p>Does not cause any RF activity and does not block. |
| * |
| * @param tag an NFC-A compatible tag |
| * @return NFC-A object |
| */ |
| public static NfcA get(Tag tag) { |
| if (!tag.hasTech(TagTechnology.NFC_A)) return null; |
| try { |
| return new NfcA(tag); |
| } catch (RemoteException e) { |
| return null; |
| } |
| } |
| |
| /** @hide */ |
| public NfcA(Tag tag) throws RemoteException { |
| super(tag, TagTechnology.NFC_A); |
| Bundle extras = tag.getTechExtras(TagTechnology.NFC_A); |
| mSak = extras.getShort(EXTRA_SAK); |
| mAtqa = extras.getByteArray(EXTRA_ATQA); |
| } |
| |
| /** |
| * Return the ATQA/SENS_RES bytes from tag discovery. |
| * |
| * <p>Does not cause any RF activity and does not block. |
| * |
| * @return ATQA/SENS_RES bytes |
| */ |
| public byte[] getAtqa() { |
| return mAtqa; |
| } |
| |
| /** |
| * Return the SAK/SEL_RES bytes from tag discovery. |
| * |
| * <p>Does not cause any RF activity and does not block. |
| * |
| * @return SAK bytes |
| */ |
| public short getSak() { |
| return mSak; |
| } |
| |
| /** |
| * Send raw NFC-A commands to the tag and receive the response. |
| * |
| * <p>Applications must not append the EoD (CRC) to the payload, |
| * it will be automatically calculated. |
| * <p>Applications must only send commands that are complete bytes, |
| * for example a SENS_REQ is not possible (these are used to |
| * manage tag polling and initialization). |
| * |
| * <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum number of bytes |
| * that can be sent with {@link #transceive}. |
| * |
| * <p>This is an I/O operation and will block until complete. It must |
| * not be called from the main application thread. A blocked call will be canceled with |
| * {@link IOException} if {@link #close} is called from another thread. |
| * |
| * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission. |
| * |
| * @param data bytes to send |
| * @return bytes received in response |
| * @throws TagLostException if the tag leaves the field |
| * @throws IOException if there is an I/O failure, or this operation is canceled |
| */ |
| public byte[] transceive(byte[] data) throws IOException { |
| return transceive(data, true); |
| } |
| |
| /** |
| * Return the maximum number of bytes that can be sent with {@link #transceive}. |
| * @return the maximum number of bytes that can be sent with {@link #transceive}. |
| */ |
| public int getMaxTransceiveLength() { |
| return getMaxTransceiveLengthInternal(); |
| } |
| |
| /** |
| * Set the {@link #transceive} timeout in milliseconds. |
| * |
| * <p>The timeout only applies to {@link #transceive} on this object, |
| * and is reset to a default value when {@link #close} is called. |
| * |
| * <p>Setting a longer timeout may be useful when performing |
| * transactions that require a long processing time on the tag |
| * such as key generation. |
| * |
| * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission. |
| * |
| * @param timeout timeout value in milliseconds |
| */ |
| public void setTimeout(int timeout) { |
| try { |
| int err = mTag.getTagService().setTimeout(TagTechnology.NFC_A, timeout); |
| if (err != ErrorCodes.SUCCESS) { |
| throw new IllegalArgumentException("The supplied timeout is not valid"); |
| } |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| } |
| } |
| |
| /** |
| * Get the current {@link #transceive} timeout in milliseconds. |
| * |
| * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission. |
| * |
| * @return timeout value in milliseconds |
| */ |
| public int getTimeout() { |
| try { |
| return mTag.getTagService().getTimeout(TagTechnology.NFC_A); |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| return 0; |
| } |
| } |
| } |