现在很多做蓝牙APP的都需要同时连接多个设备，那该怎么才能同时管理多个设备呢？以下是本人的方法，主要是通过ArrayMap来管理不同设备的BluetoothGatt，然后使用各自的BluetoothGatt来和从机进行数据交互,我们可以绑定该service进行方法的调用。

public class BluetoothLeService2 extends Service {

private ArrayMap<String, BluetoothGatt> gattArrayMap = new ArrayMap<>();
private BluetoothAdapter mBluetoothAdapter;

@Override
public void onCreate() {
    super.onCreate();
    initBluetooth();
}

/**
 * 蓝牙是否开启
 */
public boolean isBluetoothEnabled() {
    return mBluetoothAdapter.isEnabled();
}


private void initBluetooth() {
    BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
    mBluetoothAdapter = bluetoothManager.getAdapter();
}


@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return super.onStartCommand(intent, Service.START_FLAG_RETRY, startId);
}


@Override
public IBinder onBind(Intent intent) {
    return mBinder;
}


public class LocalBinder extends Binder {
    public BluetoothLeService2 getService() {
        return BluetoothLeService2.this;
    }
}

private final IBinder mBinder = new LocalBinder();

@Override
public boolean onUnbind(Intent intent) {
    return super.onUnbind(intent);
}


/**
 * 连接设备
 *
 * @param address 设备地址
 */
public synchronized void connect(final String address) {
    BluetoothGatt gatt = gattArrayMap.get(address);
    if (gatt != null) {
        gatt.disconnect();
        gatt.close();
        gattArrayMap.remove(address);
    }
    BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
    if (device == null) return;
    device.connectGatt(this, false, mGattCallback);
}

//蓝牙连接，数据通信的回掉
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
    @Override
    public void onConnectionStateChange(final BluetoothGatt gatt, int status, int newState) {
        String address = gatt.getDevice().getAddress();
        if (status == BluetoothGatt.GATT_SUCCESS) {
            if (newState == BluetoothGatt.STATE_CONNECTED) {// 连接成功
                gatt.discoverServices();// 寻找服务
                gattArrayMap.put(address, gatt);
                Log.i("yushu", "connect succeed: ");
            } else if (newState == BluetoothGatt.STATE_DISCONNECTED) {// 断开连接
                onDisConnected(gatt, address);
                Log.i("yushu", "connect fail ");
            }
        } else {
            onDisConnected(gatt, address);
            Log.i("yushu", "connect fail ");
        }
    }


    @Override
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        if (status == BluetoothGatt.GATT_SUCCESS) {
            enableNotification(gatt);//notification
        }
    }


    @Override
    public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
        byte[] value = characteristic.getValue();
/**
 * 这里可以拿到设备notification回来的数据
*/

    }


    @Override
    public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
        super.onReadRemoteRssi(gatt, rssi, status);
        if (status == BluetoothGatt.GATT_SUCCESS) {

        }
    }
};


private void onDisConnected(BluetoothGatt gatt, String address) {
    gatt.disconnect();
    gatt.close();
}


/**
 * 使能通知
 */
private void enableNotification(BluetoothGatt mBluetoothGatt) {
    if (mBluetoothGatt == null) return;
    BluetoothGattService ableService = mBluetoothGatt.getService(UUIDUtils.UUID_LOST_SERVICE);
    if (ableService == null) return;
    BluetoothGattCharacteristic TxPowerLevel = ableService.getCharacteristic(UUIDUtils.UUID_LOST_ENABLE);
    if (TxPowerLevel == null) return;
    setCharacteristicNotification(mBluetoothGatt, TxPowerLevel, true);
}

/**
 * 使能通知
 */
private void setCharacteristicNotification(BluetoothGatt mBluetoothGatt, BluetoothGattCharacteristic characteristic, boolean enabled) {
    if (mBluetoothGatt == null) return;
    mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);
    if (UUIDUtils.UUID_LOST_ENABLE.equals(characteristic.getUuid())) {
        BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUIDUtils.CLIENT_CHARACTERISTIC_CONFIG);
        descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
        mBluetoothGatt.writeDescriptor(descriptor);
    }
}


/**
 * 写数据到硬件，这里的服务UUID和特这的UUID参考硬件那边，两边要对应
 */
public synchronized void writeDataToDevice(byte[] bs, String address) {
    BluetoothGatt mBluetoothGatt = gattArrayMap.get(address);
    if (mBluetoothGatt == null) return;
    BluetoothGattService alertService = mBluetoothGatt.getService(UUIDUtils.UUID_LOST_SERVICE);
    if (alertService == null) return;
    BluetoothGattCharacteristic alertLevel = alertService.getCharacteristic(UUIDUtils.UUID_LOST_WRITE);
    if (alertLevel == null) return;
    alertLevel.setValue(bs);
    alertLevel.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
    mBluetoothGatt.writeCharacteristic(alertLevel);
}


public boolean readRssi(String address) {
    BluetoothGatt bluetoothGatt = gattArrayMap.get(address);
    return bluetoothGatt != null && bluetoothGatt.readRemoteRssi();
}


public void remove(String address) {
    BluetoothGatt bluetoothGatt = gattArrayMap.get(address);
    if (bluetoothGatt != null) {
        bluetoothGatt.disconnect();
        bluetoothGatt.close();
        gattArrayMap.remove(address);
    }
}

public void disConnect(String address) {
    BluetoothGatt bluetoothGatt = gattArrayMap.get(address);
    if (bluetoothGatt != null) {
        bluetoothGatt.disconnect();
        gattArrayMap.remove(address);
    }
}


@Override
public void onDestroy() {
    gattArrayMap.clear();
    super.onDestroy();
}
}