/*
* 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 Tag. Acquire a NfcB object using get.
The primary NFC-B I/O operation is transceive. Applications must implement their own protocol stack on top of transceive.
Note: Methods that perform I/O operations require the NFC.NFC permission.
/**
* 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
/** @hide */
public static final String EXTRA_APPDATA = "appdata";
@hide
/** @hide */
public static final String EXTRA_PROTINFO = "protinfo";
private byte[] mAppData;
private byte[] mProtInfo;
Get an instance of NfcB for the given tag. Returns null if NfcB was not enumerated in Tag.getTechList. This indicates the tag does not support NFC-B.
Does not cause any RF activity and does not block.
Params: - tag – an NFC-B compatible tag
Returns: NFC-B object
/**
* 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
/** @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.
Does not cause any RF activity and does not block.
Returns: Application Data bytes from ATQB/SENSB_RES bytes
/**
* 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.
Does not cause any RF activity and does not block.
Returns: Protocol Info bytes from ATQB/SENSB_RES bytes
/**
* 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.
Applications must not append the EoD (CRC) to the payload,
it will be automatically calculated.
Applications must not send commands that manage the polling
loop and initialization (SENSB_REQ, SLOT_MARKER etc).
Use getMaxTransceiveLength to retrieve the maximum number of bytes that can be sent with transceive.
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 IOException if BasicTagTechnology.close is called from another thread.
Requires the NFC.NFC permission.
Params: - data – bytes to send
Throws: - TagLostException – if the tag leaves the field
- IOException – if there is an I/O failure, or this operation is canceled
Returns: bytes received in response
/**
* 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 transceive. Returns: the maximum number of bytes that can be sent with transceive.
/**
* 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();
}
}