Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题
在部分Android手机上,当连接上GATTService后直接requestMtu有可能会造成蓝牙连接中断,随后继续重新连接会报错Need BLUETOOTH PRIVILEGED permission
1 //扫描成功后连接gatt
2 BluetoothDevice mRemoteDevice = mBluetoothAdapter.getRemoteDevice(result.getDevice().getAddress());
3 BluetoothGatt mBluetoothGatt = mRemoteDevice.connectGatt(getContext(), false, bluetoothGattCallback);
在 BluetoothGattCallback 监听的 onConnectionStateChange(BluetoothGatt gatt, int status, int newState)方法中直接requestMtu(512) 会直接导致蓝牙断开连接
1 private int setMTUInt = 512;
2
3
4 @Override
5 public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
6 super.onConnectionStateChange(gatt, status, newState);
7
8 if (newState == BluetoothProfile.STATE_CONNECTED) { //// 连接成功
9 //虽然这里的boolean会为true但是实际上会失败,并且导致蓝牙断开链接
10 boolean requestMtu = gatt.requestMtu(setMTUInt);
11 Log.e(TAG,"设置 requestMtu:"+requestMtu);
12
13 } else if (newState == BluetoothProfile.STATE_DISCONNECTED) { // 连接断开
14 //清除缓存,防止Need BLUETOOTH PRIVILEGED permission
15 refreshDeviceCache();
16 //将MTU的值减少,值可以随意设置
17 setMTUInt -= 100;
18 // 关闭GATT客户端
19 mBluetoothGatt.close();
20 }
21 }
在监听的onMtuChanged(BluetoothGatt gatt, int mtu, int status)方法中,确认mtu设置成功后,再去请求特征值
1 @Override
2 public void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {
3 super.onMtuChanged(gatt, mtu, status);
4
5 // 开始查找GATT服务器提供的服务
6 gatt.discoverServices();
7
8 }
随后在监听的onServicesDiscovered(BluetoothGatt gatt, int status)方法中设置特征
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
super.onServicesDiscovered(gatt, status);
if (status == BluetoothGatt.GATT_SUCCESS) {
//设置特征值
requestCharacteristic();
}
}
清除缓存的方法,gatt本身有提供清除缓存方法,但是不给外部直接调用,所以使用反射的方式进行调用,建议在每次开启扫描设备时也清除一下缓存,防止链接过其他设备后直接链接新设备报错 java.lang.SecurityException: Need BLUETOOTH PRIVILEGED permission: Neither user 10208 nor current process has android.permission.BLUETOOTH_PRIVILEGED.
1 public boolean refreshDeviceCache() {
2 if (mBluetoothGatt != null) {
3 Log.e(TAG,"清除缓存 refreshDeviceCache");
4 try {
5 BluetoothGatt localBluetoothGatt = mBluetoothGatt;
6 Method localMethod = localBluetoothGatt.getClass().getMethod(
7 "refresh", new Class[0]);
8 if (localMethod != null) {
9 boolean bool = ((Boolean) localMethod.invoke(
10 localBluetoothGatt, new Object[0])).booleanValue();
11 return bool;
12 }
13 } catch (Exception localException) {
14 Log.i(TAG, "An exception occured while refreshing device");
15 }
16 }
17 return false;
18 }
Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题Need BLUETOOTH PRIVILEGED permission以及requestMtu导致蓝牙断连问题