Develop Reference

Could not able to connect Bluetooth in android

Im trying develop Bluetooth chat application.
When I am trying connect another device via Bluetooth getting below error :
2020-08-20 22:54:28.501 3710-3729/com..btconnection I/OpenGLRenderer: Initialized EGL, version 1.4
2020-08-20 22:54:28.501 3710-3729/com.test.btconnection D/OpenGLRenderer: Swap behavior 1
2020-08-20 22:54:31.736 3710-3710/com.test.btconnection V/BoostFramework: BoostFramework() : mPerf = com.qualcomm.qti.Performance#ae9591c
2020-08-20 22:54:32.141 3710-3710/com.test.btconnection W/IInputConnectionWrapper: finishComposingText on inactive InputConnection
2020-08-20 22:54:38.014 3710-3849/com.test.btconnection W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
2020-08-20 22:54:38.040 3710-3710/com.test.btconnection W/InputEventReceiver: Attempted to finish an input event but the input event receiver has already been disposed.
2020-08-20 22:54:40.868 3710-3710/com.test.btconnection I/Toast: Show toast from OpPackageName:com.test.btconnection, PackageName:com.test.btconnection
MainActivity.java
public class MainActivity extends AppCompatActivity {
private TextView status;
private Button btnConnect;
private ListView listView;
private Dialog dialog;
private TextInputLayout inputLayout;
private ArrayAdapter<String> chatAdapter;
private ArrayList<String> chatMessages;
private BluetoothAdapter bluetoothAdapter;
public static final int MESSAGE_STATE_CHANGE = 1;
public static final int MESSAGE_READ = 2;
public static final int MESSAGE_WRITE = 3;
public static final int MESSAGE_DEVICE_OBJECT = 4;
public static final int MESSAGE_TOAST = 5;
public static final String DEVICE_OBJECT = "device_name";
private static final int REQUEST_ENABLE_BLUETOOTH = 1;
private ChatController chatController;
private BluetoothDevice connectingDevice;
private ArrayAdapter<String> discoveredDevicesAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main1);
findViewsByIds();
//check device support bluetooth or not
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
Toast.makeText(this, "Bluetooth is not available!", Toast.LENGTH_SHORT).show();
finish();
}
//show bluetooth devices dialog when click connect button
btnConnect.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
showPrinterPickDialog();
}
});
//set chat adapter
chatMessages = new ArrayList<>();
chatAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, chatMessages);
listView.setAdapter(chatAdapter);
}
private Handler handler = new Handler(new Handler.Callback() {
#Override
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case ChatController.STATE_CONNECTED:
setStatus("Connected to: " + connectingDevice.getName());
btnConnect.setEnabled(false);
break;
case ChatController.STATE_CONNECTING:
setStatus("Connecting...");
btnConnect.setEnabled(false);
break;
case ChatController.STATE_LISTEN:
case ChatController.STATE_NONE:
setStatus("Not connected");
break;
}
break;
case MESSAGE_WRITE:
byte[] writeBuf = (byte[]) msg.obj;
String writeMessage = new String(writeBuf);
chatMessages.add("Me: " + writeMessage);
chatAdapter.notifyDataSetChanged();
break;
case MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
String readMessage = new String(readBuf, 0, msg.arg1);
chatMessages.add(connectingDevice.getName() + ": " + readMessage);
chatAdapter.notifyDataSetChanged();
break;
case MESSAGE_DEVICE_OBJECT:
connectingDevice = msg.getData().getParcelable(DEVICE_OBJECT);
Toast.makeText(getApplicationContext(), "Connected to " + connectingDevice.getName(),
Toast.LENGTH_SHORT).show();
break;
case MESSAGE_TOAST:
Toast.makeText(getApplicationContext(), msg.getData().getString("toast"),
Toast.LENGTH_SHORT).show();
break;
}
return false;
}
});
private void showPrinterPickDialog() {
dialog = new Dialog(this);
dialog.setContentView(R.layout.layout_bluetooth);
dialog.setTitle("Bluetooth Devices");
if (bluetoothAdapter.isDiscovering()) {
bluetoothAdapter.cancelDiscovery();
}
bluetoothAdapter.startDiscovery();
//Initializing bluetooth adapters
ArrayAdapter<String> pairedDevicesAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
discoveredDevicesAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
//locate listviews and attatch the adapters
ListView listView = (ListView) dialog.findViewById(R.id.pairedDeviceList);
ListView listView2 = (ListView) dialog.findViewById(R.id.discoveredDeviceList);
listView.setAdapter(pairedDevicesAdapter);
listView2.setAdapter(discoveredDevicesAdapter);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(discoveryFinishReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(discoveryFinishReceiver, filter);
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
for (BluetoothDevice device : pairedDevices) {
pairedDevicesAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
pairedDevicesAdapter.add(getString(R.string.none_paired));
}
//Handling listview item click event
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
bluetoothAdapter.cancelDiscovery();
String info = ((TextView) view).getText().toString();
String address = info.substring(info.length() - 17);
connectToDevice(address);
dialog.dismiss();
}
});
listView2.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
bluetoothAdapter.cancelDiscovery();
String info = ((TextView) view).getText().toString();
String address = info.substring(info.length() - 17);
connectToDevice(address);
dialog.dismiss();
}
});
dialog.findViewById(R.id.cancelButton).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
dialog.setCancelable(false);
dialog.show();
}
private void setStatus(String s) {
status.setText(s);
}
private void connectToDevice(String deviceAddress) {
bluetoothAdapter.cancelDiscovery();
BluetoothDevice device = bluetoothAdapter.getRemoteDevice(deviceAddress);
chatController.connect(device);
}
private void findViewsByIds() {
status = (TextView) findViewById(R.id.status);
btnConnect = (Button) findViewById(R.id.btn_connect);
listView = (ListView) findViewById(R.id.list);
inputLayout = (TextInputLayout) findViewById(R.id.input_layout);
View btnSend = findViewById(R.id.btn_send);
btnSend.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (inputLayout.getEditText().getText().toString().equals("")) {
Toast.makeText(MainActivity.this, "Please input some texts", Toast.LENGTH_SHORT).show();
} else {
//TODO: here
sendMessage(inputLayout.getEditText().getText().toString());
inputLayout.getEditText().setText("");
}
}
});
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case REQUEST_ENABLE_BLUETOOTH:
if (resultCode == Activity.RESULT_OK) {
chatController = new ChatController(this, handler);
} else {
Toast.makeText(this, "Bluetooth still disabled, turn off application!", Toast.LENGTH_SHORT).show();
finish();
}
}
}
private void sendMessage(String message) {
if (chatController.getState() != ChatController.STATE_CONNECTED) {
Toast.makeText(this, "Connection was lost!", Toast.LENGTH_SHORT).show();
return;
}
if (message.length() > 0) {
byte[] send = message.getBytes();
chatController.write(send);
}
}
#Override
public void onStart() {
super.onStart();
if (!bluetoothAdapter.isEnabled()) {
android.content.Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BLUETOOTH);
} else {
chatController = new ChatController(this, handler);
}
}
#Override
public void onResume() {
super.onResume();
if (chatController != null) {
if (chatController.getState() == ChatController.STATE_NONE) {
chatController.start();
}
}
}
#Override
public void onDestroy() {
super.onDestroy();
if (chatController != null)
chatController.stop();
}
private final BroadcastReceiver discoveryFinishReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
discoveredDevicesAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
if (discoveredDevicesAdapter.getCount() == 0) {
discoveredDevicesAdapter.add(getString(R.string.none_found));
}
}
}
};
}
ChatController.java
public class ChatController {
private static final String APP_NAME = "BluetoothChatApp";
private static final UUID MY_UUID = UUID.fromString("8ce255c0-200a-11e0-ac64-0800200c9a66");
private final BluetoothAdapter bluetoothAdapter;
private final Handler handler;
private AcceptThread acceptThread;
private ConnectThread connectThread;
private ReadWriteThread connectedThread;
private int state;
static final int STATE_NONE = 0;
static final int STATE_LISTEN = 1;
static final int STATE_CONNECTING = 2;
static final int STATE_CONNECTED = 3;
public ChatController(Context context, Handler handler) {
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
state = STATE_NONE;
this.handler = handler;
}
// Set the current state of the chat connection
private synchronized void setState(int state) {
this.state = state;
handler.obtainMessage(MainActivity.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
}
// get current connection state
public synchronized int getState() {
return state;
}
// start service
public synchronized void start() {
// Cancel any thread
if (connectThread != null) {
connectThread.cancel();
connectThread = null;
}
// Cancel any running thresd
if (connectedThread != null) {
connectedThread.cancel();
connectedThread = null;
}
setState(STATE_LISTEN);
if (acceptThread == null) {
acceptThread = new AcceptThread();
acceptThread.start();
}
}
// initiate connection to remote device
public synchronized void connect(BluetoothDevice device) {
// Cancel any thread
if (state == STATE_CONNECTING) {
if (connectThread != null) {
connectThread.cancel();
connectThread = null;
}
}
// Cancel running thread
if (connectedThread != null) {
connectedThread.cancel();
connectedThread = null;
}
// Start the thread to connect with the given device
connectThread = new ConnectThread(device);
connectThread.start();
setState(STATE_CONNECTING);
}
// manage Bluetooth connection
public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
// Cancel the thread
if (connectThread != null) {
connectThread.cancel();
connectThread = null;
}
// Cancel running thread
if (connectedThread != null) {
connectedThread.cancel();
connectedThread = null;
}
if (acceptThread != null) {
acceptThread.cancel();
acceptThread = null;
}
// Start the thread to manage the connection and perform transmissions
connectedThread = new ReadWriteThread(socket);
connectedThread.start();
// Send the name of the connected device back to the UI Activity
Message msg = handler.obtainMessage(MainActivity.MESSAGE_DEVICE_OBJECT);
Bundle bundle = new Bundle();
bundle.putParcelable(MainActivity.DEVICE_OBJECT, device);
msg.setData(bundle);
handler.sendMessage(msg);
setState(STATE_CONNECTED);
}
// stop all threads
public synchronized void stop() {
if (connectThread != null) {
connectThread.cancel();
connectThread = null;
}
if (connectedThread != null) {
connectedThread.cancel();
connectedThread = null;
}
if (acceptThread != null) {
acceptThread.cancel();
acceptThread = null;
}
setState(STATE_NONE);
}
public void write(byte[] out) {
ReadWriteThread r;
synchronized (this) {
if (state != STATE_CONNECTED)
return;
r = connectedThread;
}
r.write(out);
}
private void connectionFailed() {
Message msg = handler.obtainMessage(MainActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString("toast", "Unable to connect device");
msg.setData(bundle);
handler.sendMessage(msg);
// Start the service over to restart listening mode
ChatController.this.start();
}
private void connectionLost() {
Message msg = handler.obtainMessage(MainActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString("toast", "Device connection was lost");
msg.setData(bundle);
handler.sendMessage(msg);
// Start the service over to restart listening mode
ChatController.this.start();
}
// runs while listening for incoming connections
private class AcceptThread extends Thread {
private final BluetoothServerSocket serverSocket;
public AcceptThread() {
BluetoothServerSocket tmp = null;
try {
tmp = bluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord(APP_NAME, MY_UUID);
} catch (IOException ex) {
ex.printStackTrace();
}
serverSocket = tmp;
}
public void run() {
setName("AcceptThread");
BluetoothSocket socket;
while (state != STATE_CONNECTED) {
try {
socket = serverSocket.accept();
} catch (IOException e) {
break;
}
// If a connection was accepted
if (socket != null) {
synchronized (ChatController.this) {
switch (state) {
case STATE_LISTEN:
case STATE_CONNECTING:
// start the connected thread.
connected(socket, socket.getRemoteDevice());
break;
case STATE_NONE:
case STATE_CONNECTED:
// Either not ready or already connected. Terminate
// new socket.
try {
socket.close();
} catch (IOException e) {
}
break;
}
}
}
}
}
public void cancel() {
try {
serverSocket.close();
} catch (IOException e) {
}
}
}
// runs while attempting to make an outgoing connection
private class ConnectThread extends Thread {
private final BluetoothSocket socket;
private final BluetoothDevice device;
public ConnectThread(BluetoothDevice device) {
this.device = device;
BluetoothSocket tmp = null;
try {
tmp = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
e.printStackTrace();
}
socket = tmp;
}
public void run() {
setName("ConnectThread");
// Always cancel discovery because it will slow down a connection
bluetoothAdapter.cancelDiscovery();
// Make a connection to the BluetoothSocket
try {
socket.connect();
} catch (IOException e) {
try {
socket.close();
} catch (IOException e2) {
}
connectionFailed();
return;
}
// Reset the ConnectThread because we're done
synchronized (ChatController.this) {
connectThread = null;
}
// Start the connected thread
connected(socket, device);
}
public void cancel() {
try {
socket.close();
} catch (IOException e) {
}
}
}
// runs during a connection with a remote device
private class ReadWriteThread extends Thread {
private final BluetoothSocket bluetoothSocket;
private final InputStream inputStream;
private final OutputStream outputStream;
public ReadWriteThread(BluetoothSocket socket) {
this.bluetoothSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
inputStream = tmpIn;
outputStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[1024];
int bytes;
// Keep listening to the InputStream
while (true) {
try {
// Read from the InputStream
bytes = inputStream.read(buffer);
// Send the obtained bytes to the UI Activity
handler.obtainMessage(MainActivity.MESSAGE_READ, bytes, -1,
buffer).sendToTarget();
} catch (IOException e) {
connectionLost();
// Start the service over to restart listening mode
ChatController.this.start();
break;
}
}
}
// write to OutputStream
public void write(byte[] buffer) {
try {
outputStream.write(buffer);
handler.obtainMessage(MainActivity.MESSAGE_WRITE, -1, -1,
buffer).sendToTarget();
} catch (IOException e) {
}
}
public void cancel() {
try {
bluetoothSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Can you please me to resolve this error.
I have followed this link (getbluetoothservice() called with no bluetoothmanagercallback). I could not understand.

Issue is resolved after changing the UUID.
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

bluetooth as service and send/receive from it

I'm trying to recieve/send data to arduino board using bluetooth, and I can connect to board from one activity. I know that I can make my other activities connect with bluetooth using service but I don't know how to make bluetooth as service. and i don't know how to send and recieve from it.
my Paired Devices code:
public class BTConnect extends AppCompatActivity {
private static final String TAG = "BTConnect";
ListView IdLista;
public static String EXTRA_DEVICE_ADDRESS = "device_address";
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_btconnect);
}
#Override
public void onResume()
{
super.onResume();
//---------------------------------
VerificarEstadoBT();
//
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.btconnect_nombre);
IdLista = (ListView)findViewById(R.id.Id2);
IdLista.setAdapter(mPairedDevicesArrayAdapter);
IdLista.setOnItemClickListener(mDeviceClickListener);
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
if (pairedDevices.size() > 0)
{
for (BluetoothDevice device: pairedDevices) {
mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
}
}
private AdapterView.OnItemClickListener mDeviceClickListener = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView av, View v, int arg2, long arg3) {
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
Intent i = new Intent(BTConnect.this, device.class);
i.putExtra(EXTRA_DEVICE_ADDRESS, address);
startActivity(i);
}
};
private void VerificarEstadoBT() {
mBtAdapter= BluetoothAdapter.getDefaultAdapter();
if(mBtAdapter==null) {
Toast.makeText(getBaseContext(), "the device can't connect to BT", Toast.LENGTH_SHORT).show();
} else {
if (mBtAdapter.isEnabled()) {
Log.d(TAG, "...Bluetooth Activation...");
} else {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}}
And my first activity 'device' :
public class device extends AppCompatActivity {
Button IdEncender, IdApagar,IdDesconectar,IdReset;
ArrayList<String> addArray = new ArrayList<String>();
ListView show;
//-------------------------------------------
Handler bluetoothIn;
final int handlerState = 0;
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private StringBuilder DataStringIN = new StringBuilder();
private ConnectedThread MyConexionBT;
// Identificador unico de servicio - SPP UUID
private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// String para la direccion MAC
private static String address = null;
//-------------------------------------------
#SuppressLint("HandlerLeak")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_device);
IdEncender = (Button) findViewById(R.id.IdEncender);
IdApagar = (Button) findViewById(R.id.IdApagar);
IdDesconectar = (Button) findViewById(R.id.IdDisconectar);
show = (ListView) findViewById(R.id.LIST1) ;
IdReset=(Button)findViewById(R.id.IdReset);
bluetoothIn = new Handler() {
public void handleMessage(android.os.Message msg) {
if (msg.what == handlerState) {
String readMessage = (String) msg.obj;
DataStringIN.append(readMessage);
int endOfLineIndex = DataStringIN.indexOf("#");
if (endOfLineIndex > 0) {
String dataInPrint = DataStringIN.substring(0, endOfLineIndex);
String newline = "\r\n";
DataStringIN.delete(0, DataStringIN.length());
//--List adapter--//
addArray.add(dataInPrint);
ArrayAdapter<String> adapter =new ArrayAdapter<String>(device.this, android.R.layout.simple_list_item_1, addArray);
show.setAdapter(adapter);
}
}
};
btAdapter = BluetoothAdapter.getDefaultAdapter(); // get Bluetooth adapter
VerificarEstadoBT();
IdEncender.setOnClickListener(new View.OnClickListener() {
public void onClick(View v)
{
MyConexionBT.write("1");
}
});
IdApagar.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
MyConexionBT.write("0");
}
});
IdDesconectar.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (btSocket!=null)
{
try {btSocket.close();}
catch (IOException e)
{ Toast.makeText(getBaseContext(), "Error", Toast.LENGTH_SHORT).show();;}
}
finish();
}
});
configurebutton();
}
private void configurebutton() {
Button startbutton = (Button)findViewById(R.id.Start);
startbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(device.this,chart.class));
}
});
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException
{
return device.createRfcommSocketToServiceRecord(BTMODULEUUID);
}
#Override
public void onResume()
{
super.onResume();
Intent intent = getIntent();
address = intent.getStringExtra(BTConnect.EXTRA_DEVICE_ADDRESS);
BluetoothDevice device = btAdapter.getRemoteDevice(address);
try
{
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
Toast.makeText(getBaseContext(), "fail", Toast.LENGTH_LONG).show();
}
try
{
btSocket.connect();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {}
}
MyConexionBT = new ConnectedThread(btSocket);
MyConexionBT.start();
}
#Override
public void onPause()
{
super.onPause();
try
{
btSocket.close();
} catch (IOException e2) {}
}
private void VerificarEstadoBT() {
if(btAdapter==null) {
Toast.makeText(getBaseContext(), "error in bluetooth connection", Toast.LENGTH_LONG).show();
} else {
if (btAdapter.isEnabled()) {
} else {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}
public void savefile(String file, String text){
try {
FileOutputStream fos = openFileOutput(file, Context.MODE_APPEND);
fos.write(text.getBytes());
fos.close();
Toast.makeText(device.this, "saved!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(device.this,"error",Toast.LENGTH_LONG).show();
}
}
//Crea la clase que permite crear el evento de conexion
private class ConnectedThread extends Thread
{
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket)
{
InputStream tmpIn = null;
OutputStream tmpOut = null;
try
{
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run()
{
byte[] buffer = new byte[256];
int bytes;
while (true) {
try {
bytes = mmInStream.read(buffer);
String readMessage = new String(buffer, 0, bytes);
bluetoothIn.obtainMessage(handlerState, bytes, -1, readMessage).sendToTarget();
} catch (IOException e) {
break;
}
}
}
public void write(String input)
{
try {
mmOutStream.write(input.getBytes());
}
catch (IOException e)
{
Toast.makeText(getBaseContext(), "fail to connect", Toast.LENGTH_LONG).show();
finish();
}
}
}
}

If shortly move your connection/message_exchange logic to Thread/Runnable and start it from Service. You can exchange data between Service and Activity/Activities with BroadcastReceivers or Messenger. I also recommend you to use Bluetooth lib:
implementation 'me.aflak.libraries:bluetooth:1.3.4' this one already have inside thread so it is become easy to embed in your service.
Example code of service which use this lib and Messenger:
private ArrayList<Messenger> mClients = new ArrayList<>();
final private Messenger inComingMessenger = new Messenger(mIncomingHandler);
#SuppressLint("HandlerLeak")
final Handler mIncomingHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case Constants.MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
Log.d(TAG, "handleMessage: new client connected. Total: " + mClients.size());
break;
case Constants.MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
Log.d(TAG, "handleMessage: client disconnected. Total: " + mClients.size());
break;
case Constants.MSG_YOUR_MESSAGE_TYPE:
String val = (String) msg.obj;
// stuff to do
break;
}
}
};
/**
* Send message to connected activities
*/
public void sendMessageToClients(int msgSignal, Object obj) {
if (mClients.size() == 0)
return;
sendMessage(mClients.get(0), Message.obtain(null, msgSignal, obj));
for (int i = 1; i < mClients.size(); i++) {
if (mClients.get(i) == null)
continue;
sendMessage(mClients.get(i), Message.obtain(null, msgSignal, obj));
}
}
/**
* Send message to binded activity
*/
private void sendMessage(Messenger msgr, Message msg) {
try {
msgr.send((msg));
} catch (RemoteException e) {
Log.e(TAG, "can't send message", e);
e.printStackTrace();
}
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
Log.d(TAG, "onStartCommand");
return START_STICKY;
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
Log.d(TAG, "onBind");
return inComingMessenger.getBinder();
}
#Override
public void onCreate() {
super.onCreate();
bleDevices = new ArrayList<>();
if(bluetooth == null) {
bluetooth = new Bluetooth(this);
bluetooth.setBluetoothCallback(new BluetoothCallback() {
#Override
public void onBluetoothTurningOn() {}
#Override
public void onBluetoothOn() {}
#Override
public void onBluetoothTurningOff() {
bluetooth = null;
}
#Override
public void onBluetoothOff() { }
#Override
public void onUserDeniedActivation() {
// when using bluetooth.showEnableDialog()
// you will also have to call bluetooth.onActivityResult()
}
});
bluetooth.setDiscoveryCallback(new DiscoveryCallback() {
#Override public void onDiscoveryStarted() {
}
#Override public void onDiscoveryFinished() {
bleDevices.clear();
}
#Override public void onDeviceFound(BluetoothDevice device) {
if(bleDevices.indexOf(device)<0) {
bleDevices.add(device);
Log.d(TAG, "Found new device while scanning: "+device.getAddress());
sendMessageToClients(Constants.MSG_BLE_DEVICE_FOUND, device);
}
}
#Override public void onDevicePaired(BluetoothDevice device) {}
#Override public void onDeviceUnpaired(BluetoothDevice device) {}
#Override public void onError(String message) {
Log.e(TAG, "DiscoveryCallback onError "+message);
}
});
bluetooth.setDeviceCallback(new DeviceCallback() {
#Override public void onDeviceConnected(BluetoothDevice device) { }
#Override public void onDeviceDisconnected(BluetoothDevice device, String message) { }
#Override public void onMessage(String message) {
// Handle your message
yourHandleFunction(message.replaceAll(" ",""));
Log.d(TAG, message);
}
#Override public void onError(String message) {
Log.e(TAG, "DeviceCallback onError "+message);
}
#Override public void onConnectError(BluetoothDevice device, String message) { }
});
bluetooth.onStart();
}
connectToSavedDevice();
}
}
private void connectToSavedDevice() {
Log.d(TAG, "connectToSavedDevice state="+getState());
if(getState() != STATE_DISCONNECTED) return;
SharedPreferences pref = getSharedPreferences(App.TAG, 0);
String address = pref.getString(Constants.PREF_AUTO_CONNECT_TO_ADDRESS, null);
if(address == null) {
Log.d(TAG, "saved address==null start scan for devices");
scanDevices();
return;
}
BluetoothDevice device = bluetoothAdapter.getRemoteDevice(address);
if(device!=null) {
Log.d(TAG, "device found try to connect/bound, connect to Arduino");
bluetooth.connectToAddress(address,false);
}
}
In activity implement ServiceConnection interface:
protected synchronized void unbindService() {
if (!isBound()) {
return;
}
// lock object (prevents access to service while disconnecting)
synchronized (outComingMessenger) {
sendMessageToService(Message.obtain(null, Constants.MSG_UNREGISTER_CLIENT));
unbindService(this);
outComingMessenger = null;
}
}
protected void bindService() {
bindService(mServiceIntent, this, BIND_AUTO_CREATE);
}
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
outComingMessenger = new Messenger(service);
final Message msg = Message.obtain(null, Constants.MSG_REGISTER_CLIENT);
msg.replyTo = inComingMessenger;
msg.obj = getClass().getSimpleName();
sendMessageToService(msg);
sendMessageToService(Constants.MSG_CHECK_IS_CONNECTION_READY);
}
#Override
public void onServiceDisconnected(ComponentName name) {
outComingMessenger = null;
bindService();
}
/**
* Send message to service
*/
protected void sendMessageToService(Message msg) {
if (!isBound()) {
return;
}
try {
msg.replyTo = inComingMessenger;
outComingMessenger.send(msg);
} catch (RemoteException e) {
}
}
/**
* Send simple message to connected service
* #param messageId
*/
protected void sendMessageToService(int messageId) {
sendMessageToService(Message.obtain(null, messageId));
}
/**
* Send simple message to connected service
* #param messageId
*/
protected void sendMessageToService(int messageId, Object obj) {
sendMessageToService(Message.obtain(null, messageId, obj));
}
/**
* Service is connected?
*/
protected final boolean isBound() {
return outComingMessenger != null;
}
#SuppressLint("HandlerLeak")
private final Handler mIncomingHandler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case Constants.MSG_YOUR_MESSAGE:
int res = (int) msg.obj;
break;
case Constants.MSG_CONNECTION_READY:
isReady = (boolean) msg.obj;
if(isReady) {
// show toast or what you want to do with the UI
} else {
// do something else
}
break;
case Constants.MSG_BLE_DEVICE_FOUND:
BluetoothDevice device = (BluetoothDevice)msg.obj;
SharedPreferences pref = getSharedPreferences(App.TAG, 0);
String deviceAddress = pref.getString(Constants.PREF_AUTO_CONNECT_TO_ADDRESS, null);
break;
}
}
};
final private Messenger inComingMessenger = new Messenger(mIncomingHandler);

bluetooth connection in android (server and client wrong)

i use these codes but Bluetooth socket never created.
i have two phones, SAMSUNG galaxy S5 and Huwaii. i run server code on Huwaii and client code in galaxy but state string in both is "waiting", that means never can create Bluetooth socket, these codes are exactly copied from GOOGLE android Tutriol and I don't know what wrong is.
myClientCode is this :
public class BluetoothActivity extends Activity implements OnItemClickListener {
protected static final int SUCCESS_CONNECT = 0;
public static final int MESSAGE_READ = 1;
TextView state;
BluetoothAdapter btadaptor;
ListView list;
ArrayAdapter<String> array;
Set<BluetoothDevice> btarray;
ArrayList<String> pairedDevices;
ArrayList<BluetoothDevice> devices;
IntentFilter filter;
BroadcastReceiver receiver;
Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
switch (msg.what) {
case SUCCESS_CONNECT:
//Do something
ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket) msg.obj);
Toast.makeText(getApplicationContext(), "connected", 0).show();
String s = "SSSSSS";
connectedThread.write(s.getBytes());
break;
case MESSAGE_READ:
byte[] readbuf = (byte[]) msg.obj;
String string = new String(readbuf);
Toast.makeText(getApplicationContext(), "sus message", 0).show();
break;
}
}
};
public static final UUID MY_UUID = UUID.fromString("0efe5656-27d7-11e6-b67b-9e71128cae77");
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
if (btadaptor == null)
Toast.makeText(getApplicationContext(), "bluetooth not supported", Toast.LENGTH_SHORT).show();
else
{
if ( !btadaptor.enable())
{
startbt();
}
getPairedDevice();
startActivity();
}
}
private void startActivity() {
btadaptor.cancelDiscovery();
btadaptor.startDiscovery();
}
private void getPairedDevice() {
btarray = btadaptor.getBondedDevices();
if (btarray.size() > 0)
{
for (BluetoothDevice bt: btarray)
{
pairedDevices.add(bt.getName());
// Toast.makeText(getApplicationContext(), bt.getName(), 0).show();
}
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1)
if (resultCode == RESULT_CANCELED)
{
Toast.makeText(getApplicationContext(), "you need to turn on the bluetooth to continue", Toast.LENGTH_SHORT);
finish();
}
super.onActivityResult(requestCode, resultCode, data);
}
private void init() {
state = (TextView) findViewById(R.id.textView1);
state.setText("waitingforlist");
list = (ListView) findViewById(R.id.listView);
list.setOnItemClickListener(this);
array = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1);
list.setAdapter(array);
btadaptor = BluetoothAdapter.getDefaultAdapter();
pairedDevices = new ArrayList<String>();
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
devices = new ArrayList<BluetoothDevice>();
receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context contex, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action))
{
BluetoothDevice bt = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
devices.add(bt);
String s = "";
for (int a = 0; a < pairedDevices.size(); a++) {
if (bt.getName().equals(pairedDevices.get(a))) {
s = "(PAIRED)";
}
}
array.add(bt.getName() + s + "\n" + bt.getAddress());
}
}
};
registerReceiver(receiver, filter);
}
#Override
protected void onPause() {
unregisterReceiver(receiver);
super.onPause();
}
protected void startbt() {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1);
}
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
if (btadaptor.isDiscovering()) {
btadaptor.cancelDiscovery();
}
Toast.makeText(getApplicationContext(), array.getItem(arg2), 0).show();
if (array.getItem(arg2).contains("PAIRED")) {
// Toast.makeText(getApplicationContext(), "OK", 0).show();
BluetoothDevice selectedDevice = devices.get(arg2);
Toast.makeText(getApplicationContext(), selectedDevice.getAddress(), 0).show();
ConnectThread connectThread = new ConnectThread(selectedDevice);
state.setText("CreatedThread");
connectThread.start();
}
else
Toast.makeText(getApplicationContext(), "Device is not Paried", 0).show();
}
public class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
}
catch (IOException e) {}
mmSocket = tmp;
state.setText(device.getName());
}
#Override
public void run() {
// Cancel discovery because it will slow down the connection
// btadaptor.cancelDiscovery();
// state.setText("DONE RUN2");
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
state.setText("waiting");
mmSocket.connect();
state.setText("connected");
}
catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
}
catch (IOException closeException) {}
return;
}
// Do work to manage the connection (in a separate thread)
// manageConnectedSocket(mmSocket);
}
}
/** Will cancel an in-progress connection, and close the socket */
/* public void cancel() {
try {
mmSocket.close();
}
catch (IOException e) {}
}
}
*/
///////////////////////
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
}
catch (IOException e) {}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
#Override
public void run() {
byte[] buffer; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
buffer = new byte[1024];
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
}
catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
}
catch (IOException e) {}
}
}
}
myServerCode is this :
public class BluetoothActivity extends Activity {
protected static final int SUCCESS_CONNECT = 0;
public static final int MESSAGE_READ = 1;
Button bt;
BluetoothAdapter btadaptor;
TextView state;
Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
switch (msg.what) {
case SUCCESS_CONNECT:
//Do something
ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket) msg.obj);
Toast.makeText(getApplicationContext(), "connected", 0).show();
String s = "SSSSSS";
connectedThread.write(s.getBytes());
break;
case MESSAGE_READ:
byte[] readbuf = (byte[]) msg.obj;
String string = new String(readbuf);
Toast.makeText(getApplicationContext(), "sus message", 0).show();
break;
}
}
};
public static final UUID MY_UUID = UUID.fromString("0efe5656-27d7-11e6-b67b-9e71128cae77");
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
if (btadaptor == null)
Toast.makeText(getApplicationContext(), "bluetooth not supported", Toast.LENGTH_SHORT).show();
else
{
if ( !btadaptor.enable())
{
startbt();
}
startActivity();
startDiscovering();
OnClickListener temp = new OnClickListener() {
#Override
public void onClick(View arg0) {
AcceptThread acceptThread = new AcceptThread();
state.setText("THreadCreAted");
acceptThread.start();
}
};
bt.setOnClickListener(temp);
}
}
private void startActivity() {
btadaptor.cancelDiscovery();
btadaptor.startDiscovery();
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1)
if (resultCode == RESULT_CANCELED)
{
Toast.makeText(getApplicationContext(), "you need to turn on the bluetooth to continue", Toast.LENGTH_SHORT);
}
super.onActivityResult(requestCode, resultCode, data);
}
private void init() {
bt = (Button) findViewById(R.id.button1);
state = (TextView) findViewById(R.id.textView1);
state.setText("START");
btadaptor = BluetoothAdapter.getDefaultAdapter();
}
private void startDiscovering() {
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
state.setText("StartDiscovering");
}
protected void startbt() {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1);
}
private class AcceptThread extends Thread {
private final BluetoothServerSocket mmServerSocket;
public AcceptThread() {
btadaptor.cancelDiscovery();
// Use a temporary object that is later assigned to mmServerSocket,
// because mmServerSocket is final
BluetoothServerSocket tmp = null;
try {
// MY_UUID is the app's UUID string, also used by the client code
tmp = btadaptor.listenUsingRfcommWithServiceRecord("MYAPP", MY_UUID);
}
catch (IOException e) {}
mmServerSocket = tmp;
}
#Override
public void run() {
state.setText("runStart");
BluetoothSocket socket = null;
// Keep listening until exception occurs or a socket is returned
while (true) {
try {
state.setText("WAIITING");
state.setText("WAIITING2");
socket = mmServerSocket.accept();
state.setText("ConnectionREquesRECIEVED");
}
catch (IOException e) {
break;
}
// If a connection was accepted
if (socket != null) {
state.setText("ACCEPTED");
// Do work to manage the connection (in a separate thread)
// manageConnectedSocket(socket);
try {
mmServerSocket.close();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
}
}
/** Will cancel the listening socket, and cause the thread to finish */
public void cancel() {
try {
mmServerSocket.close();
}
catch (IOException e) {}
}
}
private void manageConnectedSocket(BluetoothSocket mmSocket2) {
}
///////////////////////
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
}
catch (IOException e) {}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
#Override
public void run() {
byte[] buffer; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
buffer = new byte[1024];
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
}
catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
}
catch (IOException e) {}
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
}
catch (IOException e) {}
}
}
}
is any body know whats wrong ?
or can anybody show me very simple code (both server and client) Bluetooth socket just for connection and sending message ?

Transferring data from bluetooth to the android app

I have the following code in android studio, we have a arduino with a bluetooth module HC-05 and we are trying to send a data from a sensor via the bluetooth to the android app:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_temperature);
btnOn = (Button) findViewById(R.id.measure);
sensorView0 = (TextView) findViewById(R.id.temp);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
CheckBlueToothState();
btnOn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
try {
sendData();
} catch (IOException ex) {
}
Toast.makeText(getBaseContext(), "Start Measuring", Toast.LENGTH_SHORT).show();
}
});
}
void openBT() throws IOException {
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); //Standard //SerialPortService ID
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
bluetoothIn = new Handler() {
public void handleMessage(android.os.Message msg) {
if (msg.what == handlerState) { //if message is what we want
String readMessage = (String) msg.obj; // msg.arg1 = bytes from connect thread
recDataString.append(readMessage); //keep appending to string until ~
int endOfLineIndex = recDataString.indexOf("%"); // determine the end-of-line
if (endOfLineIndex > 0) { // make sure there data before ~
String dataInPrint = recDataString.substring(0, endOfLineIndex); // extract string
int dataLength = dataInPrint.length(); //get length of data received
if (recDataString.charAt(0) == '*') //if it starts with # we know it is what we are looking for
{
String sensor0 = recDataString.substring(1, endOfLineIndex); //get sensor value from string between indices 1-5
sensorView0.setText( sensor0 ); //update the textviews with sensor values
}
recDataString.delete(0, recDataString.length()); //clear all string data
dataInPrint = " ";
}
}
}
};
beginListenForData1();
Handler myHandler = new Handler();
myHandler.postDelayed(mMyRunnable, 1000);//Message will be delivered in 1 second.
// myLabel.setText("Bluetooth Opened");
}
void beginListenForData1() {
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];
workerThread = new Thread(new Runnable() {
public void run() {
byte[] buffer = new byte[256];
int bytes;
// Keep looping to listen for received messages
while (true) {
try {
bytes = mmInputStream.read(buffer); //read bytes from input buffer
String readMessage = new String(buffer, 0, bytes);
// Send the obtained bytes to the UI Activity via handler
bluetoothIn.obtainMessage(handlerState, bytes, -1, readMessage).sendToTarget();
} catch (IOException e) {
break;
}
}
}
});
workerThread.start();
}
private Runnable mMyRunnable = new Runnable()
{
#Override
public void run()
{
//Change state here
}
};
private void CheckBlueToothState() {
if (mBluetoothAdapter == null) {
} else {
if (mBluetoothAdapter.isEnabled()) {
if (mBluetoothAdapter.isDiscovering()) {
} else {
}
} else {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if(pairedDevices.size() > 0) {
for(BluetoothDevice device : pairedDevices) {
if(device.getName().equals("HC-05")) {
mmDevice = device;
break;
}
}
try {
openBT();
}
catch (IOException ex) {
Toast.makeText(getBaseContext(), "Connection Failure", Toast.LENGTH_LONG).show();
finish();};
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if (requestCode == REQUEST_ENABLE_BT) {
{CheckBlueToothState();
}
}
}
void sendData() throws IOException
{
String msg = "1";
msg += "\n";
mmOutputStream.write(msg.getBytes());
//myLabel.setText("Data Sent");
}
void sendData0() throws IOException
{
String msg = "0";
msg += "\n";
mmOutputStream.write(msg.getBytes());
//myLabel.setText("Data Sent");
}
#Override
public void onBackPressed() {
super.onBackPressed();
try {
sendData0();
} catch (IOException e) {
e.printStackTrace();
}
try {
closeBT();
} catch (IOException e) {
e.printStackTrace();
}
//System.exit(0);
this.finish();
}
void closeBT() throws IOException
{
stopWorker = true;
mmOutputStream.close();
mmInputStream.close();
mmSocket.close();
}
}
The code works for the second time only, so when i press the button in the app for the first time it does not show the data, but when i press it at the second time it shows the data, why is that happening?

Why is my app closing after bluetooth printer printed the text?

I watched in debugger but i can't see what's the problem.
public class MainActivity extends Activity implements OnItemClickListener{
public BluetoothAdapter BtAdaptor;
public ArrayAdapter<String> listAdaptor;
public ArrayList<String> PairedDevices;
public ArrayList<BluetoothDevice> devices;
public ListView Lista;
public Set<BluetoothDevice> DevicesArray;
public IntentFilter filter;
public BroadcastReceiver receiver;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
protected static final int SUCCES_CONNECT = 0;
public static final int MESSAGE_READ = 1;
public static final int MESSAGE_PRINTED = 2;
public Handler mHandler;
public InputStream mmInStream;
public OutputStream mmOutStream;
public ConnectedThread connectedThread;
public BluetoothDevice selectedDevice;
public BluetoothSocket mmSocket;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button scaneaza = (Button)findViewById(R.id.btnScan);
Button printeaza = (Button)findViewById(R.id.btnSend);
printeaza.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
ConnectThread connect = new ConnectThread(selectedDevice);
connect.start();
}
});
scaneaza.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// Lista.setAdapter(listAdaptor);
startDiscovery();
if(devices.size()!=0){
listAdaptor.clear();
listAdaptor.notifyDataSetChanged();
}
receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(BluetoothDevice.ACTION_FOUND.equals(action)){
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
listAdaptor.add(device.getName()+" \n "+device);
devices.add(device);
}
else if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
Toast.makeText(getApplicationContext(), "S-a terminat cautarea!", Toast.LENGTH_SHORT).show();
}
}
};
registerReceiver(receiver, filter);
IntentFilter filter2 = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(receiver, filter2);
}
});
BtAdaptor = BluetoothAdapter.getDefaultAdapter();
initiere();
if(BtAdaptor == null){
Toast.makeText(getApplicationContext(), "Dispozitivul nu are Bt", 0).show();
}
else {
if(!BtAdaptor.isEnabled()){
Intent PornesteBt = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
Intent DescoperaBt = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
startActivityForResult(PornesteBt,1);
DescoperaBt.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 120);
startActivity(DescoperaBt);
startDiscovery();
}
else {}
}
mHandler = new Handler(){
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch(msg.what){
case SUCCES_CONNECT:
connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_SHORT).show();
String s="\n Mesaj trimis pt a testa.";
connectedThread.write(s.getBytes());
break;
case MESSAGE_PRINTED:
connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
connectedThread.cancel();
break;
}
}
};
}
private void startDiscovery() {
BtAdaptor.cancelDiscovery();
BtAdaptor.startDiscovery();
}
private void initiere() {
ListView Lista = (ListView)findViewById(R.id.lView);
Lista.setOnItemClickListener(this);
listAdaptor = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,0);
Lista.setAdapter(listAdaptor);
PairedDevices = new ArrayList<String>();
filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
devices = new ArrayList<BluetoothDevice>();
}
#Override
protected void onDestroy() {
super.onPause();
unregisterReceiver(receiver);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
if(BtAdaptor.isDiscovering()){
BtAdaptor.cancelDiscovery();
}
Toast.makeText(getApplicationContext(), "device selectat", 0).show();
// Object[] o= DevicesArray.toArray();
// BluetoothDevice selectedDevice = (BluetoothDevice)o[arg2];
selectedDevice = devices.get(arg2);
}
I used ConnectThread activity from http://developer.android.com/guide/topics/connectivity/bluetooth.html
private class ConnectThread extends Thread {
// public BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
// Use a temporary object that is later assigned to mmSocket,
// because mmSocket is final
// BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
mmSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
// mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
BtAdaptor.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
// Do work to manage the connection (in a separate thread)
// manageConnectedSocket(mmSocket);
mHandler.obtainMessage(SUCCES_CONNECT,mmSocket).sendToTarget();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
Toast.makeText(getApplicationContext(), "A intrat in cancel ", Toast.LENGTH_SHORT).show();
if(mmSocket != null){
try {
mmSocket.close();
} catch (IOException e) { }
}
}
}
And ConnectedThread...
private class ConnectedThread extends Thread {
// private final BluetoothSocket mmSocket;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
// InputStream tmpIn;
// OutputStream tmpOut;
try {
// tmpIn = socket.getInputStream();
mmInStream = socket.getInputStream();
// tmpOut = socket.getOutputStream();
mmOutStream = socket.getOutputStream();
} catch (IOException e) { }
// mmInStream = tmpIn;
// mmOutStream = tmpOut;
}
public void run() {
byte[] buffer ; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
try {
buffer = new byte[1024];
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI activity
mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();
} catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mHandler.obtainMessage(MESSAGE_PRINTED).sendToTarget();
mmOutStream.write(bytes);
} catch (IOException e) { }
}
/* Call this from the main activity to shutdown the connection */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
}
I want to connect only as a client. Thanks.