/*
* 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-F (JIS 6319-4) properties and I/O operations on a Tag. Acquire a NfcF object using get.
The primary NFC-F 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-F (JIS 6319-4) properties and I/O operations on a {@link Tag}.
*
* <p>Acquire a {@link NfcF} object using {@link #get}.
* <p>The primary NFC-F 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 NfcF extends BasicTagTechnology {
private static final String TAG = "NFC";
@hide
/** @hide */
public static final String EXTRA_SC = "systemcode";
@hide
/** @hide */
public static final String EXTRA_PMM = "pmm";
private byte[] mSystemCode = null;
private byte[] mManufacturer = null;
Get an instance of NfcF for the given tag. Returns null if NfcF was not enumerated in Tag.getTechList. This indicates the tag does not support NFC-F.
Does not cause any RF activity and does not block.
Params: - tag – an NFC-F compatible tag
Returns: NFC-F object
/**
* Get an instance of {@link NfcF} for the given tag.
* <p>Returns null if {@link NfcF} was not enumerated in {@link Tag#getTechList}.
* This indicates the tag does not support NFC-F.
* <p>Does not cause any RF activity and does not block.
*
* @param tag an NFC-F compatible tag
* @return NFC-F object
*/
public static NfcF get(Tag tag) {
if (!tag.hasTech(TagTechnology.NFC_F)) return null;
try {
return new NfcF(tag);
} catch (RemoteException e) {
return null;
}
}
@hide
/** @hide */
public NfcF(Tag tag) throws RemoteException {
super(tag, TagTechnology.NFC_F);
Bundle extras = tag.getTechExtras(TagTechnology.NFC_F);
if (extras != null) {
mSystemCode = extras.getByteArray(EXTRA_SC);
mManufacturer = extras.getByteArray(EXTRA_PMM);
}
}
Return the System Code bytes from tag discovery.
Does not cause any RF activity and does not block.
Returns: System Code bytes
/**
* Return the System Code bytes from tag discovery.
*
* <p>Does not cause any RF activity and does not block.
*
* @return System Code bytes
*/
public byte[] getSystemCode() {
return mSystemCode;
}
Return the Manufacturer bytes from tag discovery.
Does not cause any RF activity and does not block.
Returns: Manufacturer bytes
/**
* Return the Manufacturer bytes from tag discovery.
*
* <p>Does not cause any RF activity and does not block.
*
* @return Manufacturer bytes
*/
public byte[] getManufacturer() {
return mManufacturer;
}
Send raw NFC-F commands to the tag and receive the response.
Applications must not prefix the SoD (preamble and sync code)
and/or append the EoD (CRC) to the payload, it will be automatically calculated.
A typical NFC-F frame for this method looks like:
LENGTH (1 byte) --- CMD (1 byte) -- IDm (8 bytes) -- PARAMS (LENGTH - 10 bytes)
Use getMaxTransceiveLength to retrieve the maximum amount 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-F commands to the tag and receive the response.
*
* <p>Applications must not prefix the SoD (preamble and sync code)
* and/or append the EoD (CRC) to the payload, it will be automatically calculated.
*
* <p>A typical NFC-F frame for this method looks like:
* <pre>
* LENGTH (1 byte) --- CMD (1 byte) -- IDm (8 bytes) -- PARAMS (LENGTH - 10 bytes)
* </pre>
*
* <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum amount 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();
}
Set the transceive timeout in milliseconds. The timeout only applies to transceive on this object, and is reset to a default value when BasicTagTechnology.close is called.
Setting a longer timeout may be useful when performing
transactions that require a long processing time on the tag
such as key generation.
Requires the NFC.NFC permission.
Params: - timeout – timeout value in milliseconds
/**
* 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_F, 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 transceive timeout in milliseconds. Requires the NFC.NFC permission.
Returns: timeout value in milliseconds
/**
* 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_F);
} catch (RemoteException e) {
Log.e(TAG, "NFC service dead", e);
return 0;
}
}
}