bluetooth lowenergy - android BLE，write operation,in the function(Setcharacteristicnotification) -

if carry out write operations,it means send data phone ble. clientconfig.setvalue(bluetoothgattdescriptor.enable_notification_value) can't run,and app stop. when writes,should call setcharacteristicnotification? besides,when write,oncharacteristicwrite staus= 133.i don't understand write good.this code.

private final expandablelistview.onchildclicklistener serviceslistclicklistner =     new expandablelistview.onchildclicklistener() {         @override         public boolean onchildclick(expandablelistview parent, view v, int groupposition,                                     int childposition, long id) {             if (mgattcharacteristics != null) {                 final bluetoothgattcharacteristic characteristic =                         mgattcharacteristics.get(groupposition).get(childposition);                  final int charaprop = characteristic.getproperties();                  if ((charaprop | bluetoothgattcharacteristic.property_read) > 0) {                     if (mnotifycharacteristic != null) {                         mbluetoothleservice.setcharacteristicnotification(                                 mnotifycharacteristic, false);                         mnotifycharacteristic = null;                     }                     mbluetoothleservice.readcharacteristic(characteristic);                  }                 if ((charaprop | bluetoothgattcharacteristic.property_write) > 0) {                          // if there active notification on characteristic, clear                          // first doesn't update data field on user interface.                          if (mnotifycharacteristic != null) {                              mbluetoothleservice.setcharacteristicnotification(                                      mnotifycharacteristic, false);                              mnotifycharacteristic = null;                          }                          mbluetoothleservice.writecharacteristic(characteristic);                 }                 if ((charaprop | bluetoothgattcharacteristic.property_notify) > 0) {                     mnotifycharacteristic = characteristic;                     system.out.println("kkkkkkkkkk+="+characteristic.getuuid());                     mbluetoothleservice.setcharacteristicnotification(                             characteristic, true);                 }                  tv_uuid.settext(characteristic.getuuid().tostring());                 intent intent=new intent();                 b.putstring("connet_sate", status);                 b.putstring("uuid", characteristic.getuuid().tostring());                 intent.putextras(b);                 intent.setclass(mygattdetail.this, functionactivity.class);                 startactivity(intent);                 return true;             }             return false;         }     };  public void setcharacteristicnotification(bluetoothgattcharacteristic characteristic,                                           boolean enabled) {     if (mbluetoothadapter == null || mbluetoothgatt == null) {         log.w(tag, "bluetoothadapter not initialized");         return;     }     mbluetoothgatt.setcharacteristicnotification(characteristic, enabled);      bluetoothgattdescriptor clientconfig = characteristic.getdescriptor(uuid.fromstring("00002902-0000-1000-8000-00805f9b34fb"));      if (enabled) {       clientconfig.setvalue(bluetoothgattdescriptor.enable_notification_value);     } else {       clientconfig.setvalue(bluetoothgattdescriptor.disable_notification_value);     }     mbluetoothgatt.writedescriptor(clientconfig); }  public static void write(string s){     final int charaprop = target_chara.getproperties();                  if ((charaprop | bluetoothgattcharacteristic.property_write) > 0) {         //注意: 以下读取的值 通过 bluetoothgattcallback#oncharacteristicread() 函数返回         target_chara.setvalue(s);         mbluetoothleservice.writecharacteristic(target_chara);     } }    public void writecharacteristic(bluetoothgattcharacteristic characteristic) {     if (mbluetoothadapter == null || mbluetoothgatt == null) {         log.w(tag, "bluetoothadapter not initialized");         return;     }     mbluetoothgatt.writecharacteristic(characteristic); }   public void oncharacteristicread(bluetoothgatt gatt,                                      bluetoothgattcharacteristic characteristic,                                      int status) {     if (status == bluetoothgatt.gatt_success) {         log.i(tag, "--oncharacteristicread called--");         byte[] sucstring=characteristic.getvalue();         string string= new string(sucstring);         broadcastupdate(action_data_available, characteristic);     }     if (mondataavailablelistener!=null)         mondataavailablelistener.oncharacteristicread(gatt, characteristic, status); }  @override public void oncharacteristicchanged(bluetoothgatt gatt,                                     bluetoothgattcharacteristic characteristic) {     system.out.println("++++++++++++++++");     broadcastupdate(action_data_available, characteristic); }  @override public void oncharacteristicwrite(bluetoothgatt gatt,         bluetoothgattcharacteristic characteristic, int status) {     // todo auto-generated method stub     //super.oncharacteristicwrite(gatt, characteristic, status);      log.w(tag, "--oncharacteristicwrite--: " + status);       //以下语句实现 发送完数据或也显示到界面上      broadcastupdate(action_data_available, characteristic); } 

133 = 0x5;

bluetoothgatt.java

/** insufficient authentication given operation */ public static final int gatt_insufficient_authentication = 0x5; 

so 133 means insufficient authentication given operation.

clientconfig can null.

bluetoothgattdescriptor clientconfig = characteristic.getdescriptor(uuid.fromstring("00002902-0000-1000-8000-00805f9b34fb")); if(clientconfig !=null){      if (enabled) {         clientconfig.setvalue(bluetoothgattdescriptor.enable_notification_value);     } else {         clientconfig.setvalue(bluetoothgattdescriptor.disable_notification_value);     }     mbluetoothgatt.writedescriptor(clientconfig); }