Firstly, unfourtanetly my English is not too good, but I hope you can understand what is my problem:) So, I am new here and new in Android too. I have two phones: Motorola Defy (with Cyanogenmond- Android 4.4.2) and a Sony Xperia J (Android 4.1.2 - not rooted). I've created an app which can connect the phone with a Lego Mindstorm NXT via bluetooth. First time, it worked perfectly on Xperia J. It connected to NXT and when I had turned off the NXT, the phone tried to reconnect. It seemed that working, but I closed the app and reopen it some times. After that, Xperia J couldn't connect to NXT, but I don't know why? I tried to delete all of the storage datas (because of the SharedPreferences), but also didn't worked. Then I restarted the phone and it seemed like it perfectly connect again. I thought I coded something wrong, but on the other phone there is no problem. Could somebody help me what can be the problem? (I'm a student, so maybe if somebody knows better idea how can I reconnect to NXT, then please tell me:D)
MainActivity:
public class MainActivity extends ActionBarActivity {
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch(msg.what) {
case BTCommunicator.DATA_RECEIVED:
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf, 0, msg.arg1);
break;
case BTCommunicator.CONNECTION_SUCCESSFULL:
Toast.makeText(MainActivity.this, "Successful connection", Toast.LENGTH_LONG).show();
BTCommunicator.getInstance().start();
break;
case BTCommunicator.CONNECTION_FAILED:
Toast.makeText(MainActivity.this, "Connection failed", Toast.LENGTH_SHORT).show();
try {
Thread.sleep(2000);
} catch (Exception ex) {}
BTCommunicator.getInstance().cancel();
connectToDevice();
break;
case BTCommunicator.CONNECTION_CLOSED:
Toast.makeText(MainActivity.this, "Connection closed", Toast.LENGTH_SHORT).show();
BTCommunicator.getInstance().cancel();
connectToDevice();
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
protected void onPause() {
BTCommunicator.getInstance().cancel();
super.onPause();
}
public void allConnection(View v) {
connectToDevice();
}
public void connectToDevice() {
SharedPreferences sharedPreferences = PreferenceManager
.getDefaultSharedPreferences(this);
String btAddress = sharedPreferences.getString(DeviceFounder.KEYBTADDRESS, "");
String selectedUUID = sharedPreferences.getString(DeviceFounder.KEYUUID, "");
Set<BluetoothDevice> pairedDevices = BTCommunicator.getInstance().getBluetoothAdapter().getBondedDevices();
boolean deviceFound = false;
for(BluetoothDevice device : pairedDevices) {
if(device.getAddress().equals(btAddress)) {
new BTConnectAsyncTask(
this, handler, device, selectedUUID).execute();
deviceFound = true;
}
}
if(!deviceFound) {
Toast.makeText(this, "Device is not paired: " + btAddress, Toast.LENGTH_LONG).show();
}
}
public void showDeviceFounder(View v) {
startActivity(new Intent(this, DeviceFounder.class));
}
}
DeviceFounder class
public class DeviceFounder extends Activity {
private DeviceListAdapter listAdapter;
public static final String KEYBTADDRESS = "BTADDRESS"; //BT MAC-cím
public static final String KEYUUID = "UUID";
public static final String UUIDVALUE = "00001101-0000-1000-8000-00805F9B34FB";
public static String KEYBTNAME = "BTNAME";
private final BroadcastReceiver foundReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
//Ha talált új eszközt, beteszi
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
//Le akarjuk tölteni az adatokat
BluetoothDevice device =
intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
listAdapter.addDevice(device);
listAdapter.notifyDataSetChanged();
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_device_founder);
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(foundReceiver, filter);
BTCommunicator.getInstance().getBluetoothAdapter().startDiscovery();
ListView listView = (ListView)findViewById(R.id.listView1);
listAdapter = new DeviceListAdapter();
listView.setAdapter(listAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
sendSelectedUUID(position);
}
});
}
@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(foundReceiver);
BTCommunicator.getInstance().cancel();
}
private void sendSelectedUUID(final int aSelectPosition) {
BluetoothDevice device = (BluetoothDevice) listAdapter.getItem(aSelectPosition);
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(KEYBTADDRESS, device.getAddress());
editor.putString(KEYUUID, UUIDVALUE);
editor.putString(KEYBTNAME, device.getName());
editor.commit();
finish();
}
}
The BTConnectAsyncTask just call this:
try {
UUID serviceUuid = UUID.fromString(selectedUUID);
BTCommunicator.getInstance().connect(device, serviceUuid, handlerStatus);
return "OK";
} catch (Exception e) {
return ("Error: "+e.getMessage());
}
And lastly the BTCommunicator class:
'public class BTCommunicator extends Thread {
public static final int DATA_RECEIVED = 0;
public static final int CONNECTION_SUCCESSFULL = 1;
public static final int CONNECTION_FAILED = 2;
public static final int CONNECTION_CLOSED = 3;
//Ez reprezentálja a fizikai BlueTooth adaptert. Ezt használva
//tudod felfedni a többi eszközt MAC-kel és BlueToothServerSocket
//segítségével figyelni a bejövő kommunikációt!
private BluetoothAdapter bluetoothAdapter = null;
//Ezen keresztül engedi a rendszer, hogy egy app kommunikáljon egy
//másik appal. Input- és OutputStreamen keresztül.
private InputStream inStream = null;
private OutputStream outStream = null;
private Handler msgHandler = null;
private static boolean enabled = false;
public static BluetoothSocket clientSocket = null;
//statikus példány kérése
private static BTCommunicator instance = null;
public static BTCommunicator getInstance() {
if(instance == null) {
instance = new BTCommunicator();
}
return instance;
}
protected BTCommunicator() {
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}
public BluetoothAdapter getBluetoothAdapter() {
return bluetoothAdapter;
}
public void connect(BluetoothDevice device, UUID uuid, Handler
handler)
{
bluetoothAdapter.cancelDiscovery();
msgHandler = handler;
enabled = true;
try {
clientSocket = device.createRfcommSocketToServiceRecord(uuid);
clientSocket.connect();
inStream = clientSocket.getInputStream();
outStream = clientSocket.getOutputStream();
handler.obtainMessage(CONNECTION_SUCCESSFULL,
"").sendToTarget();
} catch (Exception e) {
Log.e("BTCommunicator", e.getMessage());
try {
handler.obtainMessage(CONNECTION_FAILED, e.getMessage
()).sendToTarget();
clientSocket.close();
// BTCommunicator.getInstance().cancel();
//BTCommunicator.getInstance().connect(device, uuid, handler);
} catch (IOException closeException) { }
}
}
public void run() {
byte[] buffer = new byte[1024];
int bytes;
while (enabled) {
try {
bytes = inStream.read(buffer);
msgHandler.obtainMessage(DATA_RECEIVED, bytes, -1,
buffer).sendToTarget();
} catch (IOException e) {
msgHandler.obtainMessage(CONNECTION_CLOSED,
"").sendToTarget();
try {
clientSocket.close();
} catch (IOException e2) { }
break;
}
}
}
public void write(byte[] bytes) {
try {
if(outStream != null) {
outStream.write(bytes);
}
} catch (IOException e) {
Log.e("BTCOMM", e.getMessage());
}
}
public void cancel() {
enabled = false;
if (bluetoothAdapter != null)
bluetoothAdapter.cancelDiscovery();
if (msgHandler != null)
/*msgHandler.obtainMessage(CONNECTION_CLOSED,
"").sendToTarget();*/
if (outStream != null) {
try {
outStream.close();
outStream = null;
} catch (Exception e) {
}
}
if (inStream != null) {
try {
inStream.close();
inStream = null;
} catch (Exception e) {
}
}
if (clientSocket != null) {
try {
clientSocket.close();
clientSocket = null;
} catch (IOException e) {
}
}
instance = null;
}
} `
