尝试通过原生Android蓝牙LE API和基于Android开发人员的蓝牙Gatt示例（https://developer.android.com/samples/BluetoothLeGatt/index.html）连接2个蓝牙LE模块（RN4020）时遇到问题。我修改了BluetoothLeService.java来保存许多连接而不是只有一个连接。
这是我的过程：
1-启动处理连接的新服务
2-循环连接设备：
for(String address: addresses) {
mBluetoothLeService.connect(address)
}
3-找到我需要的特征
4-发送数据：
mBluetoothLeService.writeCharacteristic(address, mCharacteristic, dataArray);
问题是，当我向第一个模块发送数据时，它会完美地接收它（在BluetoothGattCallback（）中调用onCharacteristicWrite（）），然后我将数据发送到第二个模块，一切正常！但是当我尝试再次向第一个模块发送数据时，它没有收到它（在电路板上测试，并且也没有调用onCharacteristicWrite（））。
我也尝试使用Reliable Write：
btGatt.beginReliableWrite();
characteristic.setValue(bytearray);
btGatt.writeCharacteristic(characteristic);
btGatt.executeReliableWrite();
但同样的问题。回调：
onReliableWriteCompleted(BluetoothGatt gatt, int status)
状态代码为6（BluetoothGatt.GATT_REQUEST_NOT_SUPPORTED）
我检查了两个模块的连接状态，每次都连接（没有断开连接问题）。
以下是修改后的类BluetoothLeService.java：
public class BluetoothLeService extends Service {
private final static String TAG = BluetoothLeService.class.getSimpleName();
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
// private String mBluetoothDeviceAddress;
private Map<String,BluetoothGatt> mBluetoothGatts = new HashMap<>();
private int mConnectionState = STATE_DISCONNECTED;
private static final int STATE_DISCONNECTED = 0;
private static final int STATE_CONNECTING = 1;
private static final int STATE_CONNECTED = 2;
public final static String ACTION_GATT_CONNECTED =
"com.example.bluetooth.le.ACTION_GATT_CONNECTED";
public final static String ACTION_GATT_DISCONNECTED =
"com.example.bluetooth.le.ACTION_GATT_DISCONNECTED";
public final static String ACTION_GATT_SERVICES_DISCOVERED =
"com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED";
public final static String ACTION_DATA_AVAILABLE =
"com.example.bluetooth.le.ACTION_DATA_AVAILABLE";
public final static String EXTRA_DATA =
"com.example.bluetooth.le.EXTRA_DATA";
public final static String EXTRA_ADDRESS =
"com.example.bluetooth.le.EXTRA_ADDRESS";
public final static UUID UUID_HEART_RATE_MEASUREMENT =
UUID.fromString(SampleGattAttributes.HEART_RATE_MEASUREMENT);
// Implements callback methods for GATT events that the app cares about. For example,
// connection change and services discovered.
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
String intentAction;
if (newState == BluetoothProfile.STATE_CONNECTED) {
intentAction = ACTION_GATT_CONNECTED;
mConnectionState = STATE_CONNECTED;
broadcastUpdate(gatt.getDevice().getAddress(), intentAction);
Log.i(TAG, "Connected to GATT server. address: " + gatt.getDevice().getAddress());
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:" +
gatt.discoverServices());
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
intentAction = ACTION_GATT_DISCONNECTED;
mConnectionState = STATE_DISCONNECTED;
Log.i(TAG, "Disconnected from GATT server.");
broadcastUpdate(gatt.getDevice().getAddress(), intentAction);
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.i(TAG, "--onServicesDiscovered. status: " + status);
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(gatt.getDevice().getAddress(), ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic,
int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(gatt.getDevice().getAddress(), ACTION_DATA_AVAILABLE, characteristic);
}
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
super.onCharacteristicWrite(gatt, characteristic, status);
Log.i(TAG, "--onCharacteristicWrite: value: " + Arrays.toString(characteristic.getValue()));
}
@Override
public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
super.onReliableWriteCompleted(gatt, status);
Log.i(TAG, "--onReliableWriteCompleted: status: " + status);
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
broadcastUpdate(gatt.getDevice().getAddress(), ACTION_DATA_AVAILABLE, characteristic);
}
};
private void broadcastUpdate(String address, final String action) {
final Intent intent = new Intent(action);
intent.putExtra(EXTRA_ADDRESS, address);
sendBroadcast(intent);
}
private void broadcastUpdate(final String address, final String action,
final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
// This is special handling for the Heart Rate Measurement profile. Data parsing is
// carried out as per profile specifications:
// http://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.heart_rate_measurement.xml
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
int flag = characteristic.getProperties();
int format = -1;
if ((flag & 0x01) != 0) {
format = BluetoothGattCharacteristic.FORMAT_UINT16;
Log.d(TAG, "Heart rate format UINT16.");
} else {
format = BluetoothGattCharacteristic.FORMAT_UINT8;
Log.d(TAG, "Heart rate format UINT8.");
}
final int heartRate = characteristic.getIntValue(format, 1);
Log.d(TAG, String.format("Received heart rate: %d", heartRate));
intent.putExtra(EXTRA_DATA, String.valueOf(heartRate));
} else {
// For all other profiles, writes the data formatted in HEX.
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(data.length);
for (byte byteChar : data)
stringBuilder.append(String.format("%02X ", byteChar));
intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
}
}
intent.putExtra(EXTRA_ADDRESS, address);
sendBroadcast(intent);
}
public class LocalBinder extends Binder {
public BluetoothLeService getService() {
return BluetoothLeService.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
// After using a given device, you should make sure that BluetoothGatt.close() is called
// such that resources are cleaned up properly. In this particular example, close() is
// invoked when the UI is disconnected from the Service.
disconnectAll();
closeAll();
return super.onUnbind(intent);
}
private final IBinder mBinder = new LocalBinder();
/**
* Initializes a reference to the local Bluetooth adapter.
*
* @return Return true if the initialization is successful.
*/
public boolean initialize() {
// For API level 18 and above, get a reference to BluetoothAdapter through
// BluetoothManager.
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
Log.e(TAG, "Unable to initialize BluetoothManager.");
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
return false;
}
return true;
}
/**
* Connects to the GATT server hosted on the Bluetooth LE device.
*
* @param address The device address of the destination device.
* @return Return true if the connection is initiated successfully. The connection result
* is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
return false;
}
BluetoothGatt btGatt = mBluetoothGatts.get(address);
// Previously connected device. Try to reconnect.
if ( btGatt != null) {
Log.d(TAG, "---Trying to use an existing mBluetoothGatt for connection.");
if (btGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "---Device not found. Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the autoConnect
// parameter to false.
BluetoothGatt newBtGatt = device.connectGatt(this, true, mGattCallback);
Log.d(TAG, "---Trying to create a new connection. address: " + address);
mBluetoothGatts.put(address, newBtGatt);
mConnectionState = STATE_CONNECTING;
return true;
}
/**
* Disconnects an existing connection or cancel a pending connection. The disconnection result
* is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public void disconnect(String address) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (mBluetoothAdapter == null || btGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
Log.i(TAG, "disconnecting gatt");
btGatt.disconnect();
}
public void disconnectAll() {
// Connecting all devices
Iterator it = mBluetoothGatts.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry) it.next();
String address = (String) pair.getKey();
disconnect(address);
}
}
public int getConnectionState() {
return mConnectionState;
}
/**
* After using a given BLE device, the app must call this method to ensure resources are
* released properly.
*/
public void close(String address, boolean removeFromMap) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (btGatt == null) {
return;
}
Log.i(TAG, "closing gatt");
btGatt.close();
if (removeFromMap) {
mBluetoothGatts.remove(address);
}
}
public void closeAll() {
// Connecting all devices
Iterator it = mBluetoothGatts.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry) it.next();
String address = (String) pair.getKey();
close(address, false);
}
}
/**
* Request a read on a given {@code BluetoothGattCharacteristic}. The read result is reported
* asynchronously through the {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
* callback.
*
* @param characteristic The characteristic to read from.
*/
public void readCharacteristic(String address, BluetoothGattCharacteristic characteristic) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (mBluetoothAdapter == null || btGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
btGatt.readCharacteristic(characteristic);
}
public void writeCharacteristic(String address, BluetoothGattCharacteristic characteristic,
byte[] bytearray) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (mBluetoothAdapter == null || btGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
if (characteristic == null) {
Log.w(TAG, "Characteristic == null");
}
Log.i(TAG, "--> Writing characacteristic: " + Arrays.toString(bytearray) + ", device address: " + address);
// btGatt.beginReliableWrite();
characteristic.setValue(bytearray);
// BluetoothManager bluetoothManager =
// (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
// Log.i(TAG, "--connection state: " + bluetoothManager.getConnectionState(btGatt.getDevice(), BluetoothGatt.GATT_SERVER));
btGatt.writeCharacteristic(characteristic);
// btGatt.executeReliableWrite();
}
/**
* Enables or disables notification on a give characteristic.
*
* @param characteristic Characteristic to act on.
* @param enabled If true, enable notification. False otherwise.
*/
public void setCharacteristicNotification(String address, BluetoothGattCharacteristic characteristic,
boolean enabled) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (mBluetoothAdapter == null || btGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
btGatt.setCharacteristicNotification(characteristic, enabled);
// This is specific to Heart Rate Measurement.
if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) {
BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
btGatt.writeDescriptor(descriptor);
}
}
/**
* Retrieves a list of supported GATT services on the connected device. This should be
* invoked only after {@code BluetoothGatt#discoverServices()} completes successfully.
*
* @return A {@code List} of supported services.
*/
public List<BluetoothGattService> getSupportedGattServices(String address) {
BluetoothGatt btGatt = mBluetoothGatts.get(address);
if (btGatt == null) return null;
return btGatt.getServices();
}
}
处理多个BLE连接的任何想法或库？谢谢！