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/*
* 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.Tag;
import android.os.Bundle;
import android.os.RemoteException;
import java.io.IOException;
/**
* Provides access to NFC-B (ISO 14443-3B) properties and I/O operations on a {@link Tag}.
*
* <p>Acquire a {@link NfcB} object using {@link #get}.
* <p>The primary NFC-B 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 NfcB extends BasicTagTechnology {
/** @hide */
public static final String EXTRA_APPDATA = "appdata";
/** @hide */
public static final String EXTRA_PROTINFO = "protinfo";
private byte[] mAppData;
private byte[] mProtInfo;
/**
* Get an instance of {@link NfcB} for the given tag.
* <p>Returns null if {@link NfcB} was not enumerated in {@link Tag#getTechList}.
* This indicates the tag does not support NFC-B.
* <p>Does not cause any RF activity and does not block.
*
* @param tag an NFC-B compatible tag
* @return NFC-B object
*/
public static NfcB get(Tag tag) {
if (!tag.hasTech(TagTechnology.NFC_B)) return null;
try {
return new NfcB(tag);
} catch (RemoteException e) {
return null;
}
}
/** @hide */
public NfcB(Tag tag) throws RemoteException {
super(tag, TagTechnology.NFC_B);
Bundle extras = tag.getTechExtras(TagTechnology.NFC_B);
mAppData = extras.getByteArray(EXTRA_APPDATA);
mProtInfo = extras.getByteArray(EXTRA_PROTINFO);
}
/**
* Return the Application Data bytes from ATQB/SENSB_RES at tag discovery.
*
* <p>Does not cause any RF activity and does not block.
*
* @return Application Data bytes from ATQB/SENSB_RES bytes
*/
public byte[] getApplicationData() {
return mAppData;
}
/**
* Return the Protocol Info bytes from ATQB/SENSB_RES at tag discovery.
*
* <p>Does not cause any RF activity and does not block.
*
* @return Protocol Info bytes from ATQB/SENSB_RES bytes
*/
public byte[] getProtocolInfo() {
return mProtInfo;
}
/**
* Send raw NFC-B 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 not send commands that manage the polling
* loop and initialization (SENSB_REQ, SLOT_MARKER etc).
*
* <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();
}
}
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