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How can i make bluetooth connection in every Activity?

I am developing an app which sends data to the android with Bluetooth. I can send data and see from the ardunio side. I can connect the device but when I go to the another activity in the app connection has been lost. How can I keep connection open? In the Second class I can connected the device and send the data, if I have another activity how can i use active Bluetooth connection and send data?
private String mConnectedDeviceName = null;
private StringBuffer mOutStringBuffer;
private BluetoothAdapter mBluetoothAdapter = null;
private BluetoothChatService mChatService = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
// Get local Bluetooth adapter
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// If the adapter is null, then Bluetooth is not supported
FragmentActivity activity = getActivity();
if (mBluetoothAdapter == null && activity != null) {
Toast.makeText(activity, "Bluetooth is not available", Toast.LENGTH_LONG).show();
activity.finish();
}
}
#Override
public void onStart() {
super.onStart();
if (mBluetoothAdapter == null) {
return;
}
// If BT is not on, request that it be enabled.
// setupChat() will then be called during onActivityResult
if (!mBluetoothAdapter.isEnabled()) {
Intent enableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
// Otherwise, setup the chat session
} else if (mChatService == null) {
setupChat();
}
}
#Override
public void onDestroy() {
super.onDestroy();
if (mChatService != null) {
mChatService.stop();
}
}
#Override
public void onResume() {
super.onResume();
if (mChatService != null) {
// Only if the state is STATE_NONE, do we know that we haven't started already
if (mChatService.getState() == BluetoothChatService.STATE_NONE) {
// Start the Bluetooth chat services
mChatService.start();
}
}
}
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container,
#Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_bluetooth_chat, container, false);
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
rad_saat = view.findViewById(R.id.rad_saat);
rad_Co2 = view.findViewById(R.id.rad_CO2);
rad_sicaklik = view.findViewById(R.id.rad_sicaklik);
rad_Manuel = view.findViewById(R.id.rad_manuel);
opn_spinner = view.findViewById(R.id.spn_options);
radioGroup = view.findViewById(R.id.radioGroup);
spnCrd_Options = view.findViewById(R.id.spnCrd_Options);
crd_GonderButton = view.findViewById(R.id.crd_GonderButton);
txt_GonderButton = view.findViewById(R.id.txt_GonderButton);
rad_saat.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
checkButton();
}
});
rad_Co2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
checkButton();
}
});
rad_sicaklik.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
checkButton();
}
});
rad_Manuel.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
checkButton();
}
});
radioGroup.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
checkButton();
}
});
crd_GonderButton.setOnClickListener(new View.OnClickListener() {
#RequiresApi(api = Build.VERSION_CODES.O)
#Override
public void onClick(View v) {
sendButton();
}
});
txt_GonderButton.setOnClickListener(new View.OnClickListener() {
#RequiresApi(api = Build.VERSION_CODES.O)
#Override
public void onClick(View v) {
sendButton();
}
});
}
private void setupChat() {
Log.d(TAG, "setupChat()");
// Initialize the array adapter for the conversation thread
FragmentActivity activity = getActivity();
if (activity == null) {
return;
}
// Initialize the BluetoothChatService to perform bluetooth connections
mChatService = new BluetoothChatService(activity, mHandler);
// Initialize the buffer for outgoing messages
mOutStringBuffer = new StringBuffer();
}
private void ensureDiscoverable() {
if (mBluetoothAdapter.getScanMode() !=
BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
}
}
public void sendMessage(String message) {
// Check that we're actually connected before trying anything
if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
Toast.makeText(getActivity(), R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
// Check that there's actually something to send
if (message.length() > 0) {
// Get the message bytes and tell the BluetoothChatService to write
byte[] send = message.getBytes();
mChatService.write(send);
// Reset out string buffer to zero and clear the edit text field
mOutStringBuffer.setLength(0);
}
}
private TextView.OnEditorActionListener mWriteListener
= new TextView.OnEditorActionListener() {
public boolean onEditorAction(TextView view, int actionId, KeyEvent event) {
// If the action is a key-up event on the return key, send the message
if (actionId == EditorInfo.IME_NULL && event.getAction() == KeyEvent.ACTION_UP) {
String message = view.getText().toString();
sendMessage(message);
}
return true;
}
};
private void setStatus(int resId) {
FragmentActivity activity = getActivity();
if (null == activity) {
return;
}
final ActionBar actionBar = activity.getActionBar();
if (null == actionBar) {
return;
}
actionBar.setSubtitle(resId);
}
private void setStatus(CharSequence subTitle) {
FragmentActivity activity = getActivity();
if (null == activity) {
return;
}
final ActionBar actionBar = activity.getActionBar();
if (null == actionBar) {
return;
}
actionBar.setSubtitle(subTitle);
}
private void messageHandler()
{
}
public void checkButton(){
saatList = new ArrayList<String>(Arrays.asList(new String[]{"00:00 - 03:00","03:00 -06:00 ","06:00 - 09:00","09:00 - 12:00","12:00 - 15:00","15:00 - 18:00","18:00 - 21:00","21:00 - 00:00"}));
manuelList = new ArrayList<String>(Arrays.asList(new String[]{"KAPALI","AÇIK"}));
if(rad_saat.isChecked()){
atananList = saatList;
spnCrd_Options.setVisibility(View.VISIBLE);
opn_spinner.setVisibility(View.VISIBLE);
}
if(rad_Manuel.isChecked()){
atananList = manuelList;
spnCrd_Options.setVisibility(View.VISIBLE);
opn_spinner.setVisibility(View.VISIBLE);
}
if(rad_Co2.isChecked()){
opn_spinner.setVisibility(View.GONE);
spnCrd_Options.setVisibility(View.GONE);
}
if(rad_sicaklik.isChecked()){
opn_spinner.setVisibility(View.GONE);
spnCrd_Options.setVisibility(View.GONE);
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), android.R.layout.simple_spinner_item, atananList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
opn_spinner.setAdapter(adapter);
}
#RequiresApi(api = Build.VERSION_CODES.O)
public void sendButton() {
System.out.println("1. Bluettoth adapter" + mBluetoothAdapter);
modelClass = new ModelClass();
modelClass.setmBluetoothAdapter(mBluetoothAdapter);
modelClass.setmChatService(mChatService);
modelClass.setmConnectedDeviceName(mConnectedDeviceName);
modelClass.setmOutStringBuffer(mOutStringBuffer);
Intent intent = new Intent(getActivity(), SendCordinates.class);
startActivity(intent);
}
/**
* The Handler that gets information back from the BluetoothChatService
*/
private final Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
FragmentActivity activity = getActivity();
switch (msg.what) {
case Constants.MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case BluetoothChatService.STATE_CONNECTED:
setStatus(getString(R.string.title_connected_to, mConnectedDeviceName));
//textViewReceived.setText("Received:");
break;
case BluetoothChatService.STATE_CONNECTING:
setStatus(R.string.title_connecting);
break;
case BluetoothChatService.STATE_LISTEN:
case BluetoothChatService.STATE_NONE:
setStatus(R.string.title_not_connected);
break;
}
break;
case Constants.MESSAGE_WRITE:
break;
case Constants.MESSAGE_READ:
byte[] readBuf = (byte[]) msg.obj;
// construct a string from the valid bytes in the buffer
String readMessage = new String(readBuf, 0, msg.arg1);
receiveBuffer += readMessage;
if(receiveBuffer.contains("\n")) {
receiveBuffer = receiveBuffer.substring(0, receiveBuffer.length() - 1);
messageHandler();
receiveBuffer = "";
}
break;
case Constants.MESSAGE_DEVICE_NAME:
// save the connected device's name
mConnectedDeviceName = msg.getData().getString(Constants.DEVICE_NAME);
if (null != activity) {
Toast.makeText(activity, "Connected to "
+ mConnectedDeviceName, Toast.LENGTH_SHORT).show();
}
break;
case Constants.MESSAGE_TOAST:
if (null != activity) {
Toast.makeText(activity, msg.getData().getString(Constants.TOAST),
Toast.LENGTH_SHORT).show();
}
break;
}
}
};
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CONNECT_DEVICE_SECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectDevice(data, true);
}
break;
case REQUEST_CONNECT_DEVICE_INSECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectDevice(data, false);
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
setupChat();
} else {
// User did not enable Bluetooth or an error occurred
Log.d(TAG, "BT not enabled");
FragmentActivity activity = getActivity();
if (activity != null) {
Toast.makeText(activity, R.string.bt_not_enabled_leaving,
Toast.LENGTH_SHORT).show();
activity.finish();
}
}
}
}
private void connectDevice(Intent data, boolean secure) {
// Get the device MAC address
Bundle extras = data.getExtras();
if (extras == null) {
return;
}
String address = extras.getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
// Get the BluetoothDevice object
BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
// Attempt to connect to the device
mChatService.connect(device, secure);
}
#Override
public void onCreateOptionsMenu(#NonNull Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.bluetooth_chat, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.secure_connect_scan: {
// Launch the DeviceListActivity to see devices and do scan
Intent serverIntent = new Intent(getActivity(), DeviceListActivity.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_SECURE);
return true;
}
case R.id.discoverable: {
// Ensure this device is discoverable by others
ensureDiscoverable();
return true;
}
}
return false;
}
public class BluetoothChatService {
private static final String TAG = "BluetoothChatService";
private static final String NAME_SECURE = "BluetoothChatSecure";
private static final String NAME_INSECURE = "BluetoothChatInsecure";
private static final UUID MY_UUID_SECURE =
UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private static final UUID MY_UUID_INSECURE =
UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// Member fields
private final BluetoothAdapter mAdapter;
private final Handler mHandler;
private AcceptThread mSecureAcceptThread;
private AcceptThread mInsecureAcceptThread;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private int mState;
private int mNewState;
public static final int STATE_NONE = 0; // we're doing nothing
public static final int STATE_LISTEN = 1; // now listening for incoming connections
public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
public static final int STATE_CONNECTED = 3; // now connected to a remote device
public BluetoothChatService(Context context, Handler handler) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
mState = STATE_NONE;
mNewState = mState;
mHandler = handler;
}
private synchronized void updateUserInterfaceTitle() {
mState = getState();
Log.d(TAG, "updateUserInterfaceTitle() " + mNewState + " -> " + mState);
mNewState = mState;
// Give the new state to the Handler so the UI Activity can update
mHandler.obtainMessage(Constants.MESSAGE_STATE_CHANGE, mNewState, -1).sendToTarget();
}
public synchronized int getState() {
return mState;
}
public synchronized void start() {
Log.d(TAG, "start");
// Cancel any thread attempting to make a connection
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
// Start the thread to listen on a BluetoothServerSocket
if (mSecureAcceptThread == null) {
mSecureAcceptThread = new AcceptThread(true);
mSecureAcceptThread.start();
}
if (mInsecureAcceptThread == null) {
mInsecureAcceptThread = new AcceptThread(false);
mInsecureAcceptThread.start();
}
// Update UI title
updateUserInterfaceTitle();
}
public synchronized void connect(BluetoothDevice device, boolean secure) {
Log.d(TAG, "connect to: " + device);
// Cancel any thread attempting to make a connection
if (mState == STATE_CONNECTING) {
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
}
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
mConnectThread = new ConnectThread(device, secure);
mConnectThread.start();
// Update UI title
updateUserInterfaceTitle();
}
public synchronized void connected(BluetoothSocket socket, BluetoothDevice
device, final String socketType) {
Log.d(TAG, "connected, Socket Type:" + socketType);
// Cancel the thread that completed the connection
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
if (mSecureAcceptThread != null) {
mSecureAcceptThread.cancel();
mSecureAcceptThread = null;
}
if (mInsecureAcceptThread != null) {
mInsecureAcceptThread.cancel();
mInsecureAcceptThread = null;
}
mConnectedThread = new ConnectedThread(socket, socketType);
mConnectedThread.start();
Message msg = mHandler.obtainMessage(Constants.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(Constants.DEVICE_NAME, device.getName());
msg.setData(bundle);
mHandler.sendMessage(msg);
// Update UI title
updateUserInterfaceTitle();
}
public synchronized void stop() {
Log.d(TAG, "stop");
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
if (mSecureAcceptThread != null) {
mSecureAcceptThread.cancel();
mSecureAcceptThread = null;
}
if (mInsecureAcceptThread != null) {
mInsecureAcceptThread.cancel();
mInsecureAcceptThread = null;
}
mState = STATE_NONE;
// Update UI title
updateUserInterfaceTitle();
}
public void write(byte[] out) {
// Create temporary object
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (mState != STATE_CONNECTED) return;
r = mConnectedThread;
}
// Perform the write unsynchronized
r.write(out);
}
private void connectionFailed() {
// Send a failure message back to the Activity
Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(Constants.TOAST, "Unable to connect device");
msg.setData(bundle);
mHandler.sendMessage(msg);
mState = STATE_NONE;
// Update UI title
updateUserInterfaceTitle();
// Start the service over to restart listening mode
BluetoothChatService.this.start();
}
private void connectionLost() {
// Send a failure message back to the Activity
Message msg = mHandler.obtainMessage(Constants.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(Constants.TOAST, "Device connection was lost");
msg.setData(bundle);
mHandler.sendMessage(msg);
mState = STATE_NONE;
// Update UI title
updateUserInterfaceTitle();
// Start the service over to restart listening mode
BluetoothChatService.this.start();
}
private class AcceptThread extends Thread {
// The local server socket
private final BluetoothServerSocket mmServerSocket;
private String mSocketType;
public AcceptThread(boolean secure) {
BluetoothServerSocket tmp = null;
mSocketType = secure ? "Secure" : "Insecure";
try {
if (secure) {
tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME_SECURE,
MY_UUID_SECURE);
} else {
tmp = mAdapter.listenUsingInsecureRfcommWithServiceRecord(
NAME_INSECURE, MY_UUID_INSECURE);
}
} catch (IOException e) {
Log.e(TAG, "Socket Type: " + mSocketType + "listen() failed", e);
}
mmServerSocket = tmp;
mState = STATE_LISTEN;
}
public void run() {
Log.d(TAG, "Socket Type: " + mSocketType +
"BEGIN mAcceptThread" + this);
setName("AcceptThread" + mSocketType);
BluetoothSocket socket;
while (mState != STATE_CONNECTED) {
try {
// This is a blocking call and will only return on a
// successful connection or an exception
socket = mmServerSocket.accept();
} catch (IOException e) {
Log.e(TAG, "Socket Type: " + mSocketType + "accept() failed", e);
break;
}
if (socket != null) {
synchronized (BluetoothChatService.this) {
switch (mState) {
case STATE_LISTEN:
case STATE_CONNECTING:
// Situation normal. Start the connected thread.
connected(socket, socket.getRemoteDevice(),
mSocketType);
break;
case STATE_NONE:
case STATE_CONNECTED:
// Either not ready or already connected. Terminate new socket.
try {
socket.close();
} catch (IOException e) {
Log.e(TAG, "Could not close unwanted socket", e);
}
break;
}
}
}
}
Log.i(TAG, "END mAcceptThread, socket Type: " + mSocketType);
}
public void cancel() {
Log.d(TAG, "Socket Type" + mSocketType + "cancel " + this);
try {
mmServerSocket.close();
} catch (IOException e) {
Log.e(TAG, "Socket Type" + mSocketType + "close() of server failed", e);
}
}
}
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
private String mSocketType;
public ConnectThread(BluetoothDevice device, boolean secure) {
mmDevice = device;
BluetoothSocket tmp = null;
mSocketType = secure ? "Secure" : "Insecure";
try {
if (secure) {
tmp = device.createRfcommSocketToServiceRecord(
MY_UUID_SECURE);
} else {
tmp = device.createInsecureRfcommSocketToServiceRecord(
MY_UUID_INSECURE);
}
} catch (IOException e) {
Log.e(TAG, "Socket Type: " + mSocketType + "create() failed", e);
}
mmSocket = tmp;
mState = STATE_CONNECTING;
}
public void run() {
Log.i(TAG, "BEGIN mConnectThread SocketType:" + mSocketType);
setName("ConnectThread" + mSocketType);
// Always cancel discovery because it will slow down a connection
mAdapter.cancelDiscovery();
// Make a connection to the BluetoothSocket
try {
// This is a blocking call and will only return on a
// successful connection or an exception
mmSocket.connect();
} catch (IOException e) {
// Close the socket
try {
mmSocket.close();
} catch (IOException e2) {
Log.e(TAG, "unable to close() " + mSocketType +
" socket during connection failure", e2);
}
connectionFailed();
return;
}
synchronized (BluetoothChatService.this) {
mConnectThread = null;
}
// Start the connected thread
connected(mmSocket, mmDevice, mSocketType);
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect " + mSocketType + " socket failed", e);
}
}
}
/**
* This thread runs during a connection with a remote device.
* It handles all incoming and outgoing transmissions.
*/
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket, String socketType) {
Log.d(TAG, "create ConnectedThread: " + socketType);
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the BluetoothSocket input and output streams
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
Log.e(TAG, "temp sockets not created", e);
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
mState = STATE_CONNECTED;
}
public void run() {
Log.i(TAG, "BEGIN mConnectedThread");
byte[] buffer = new byte[1024];
int bytes;
// Keep listening to the InputStream while connected
while (mState == STATE_CONNECTED) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(Constants.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
connectionLost();
break;
}
}
}
/**
* Write to the connected OutStream.
*
* #param buffer The bytes to write
*/
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
// Share the sent message back to the UI Activity
mHandler.obtainMessage(Constants.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(TAG, "Exception during write", e);
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", e);
}
}
}

Create an actual service which can be bound from multiple activities.
class BluetoothService : Service() {
private val binder = LocalBinder()
override fun onBind(intent: Intent): IBinder? {
return binder
}
inner class LocalBinder : Binder() {
fun getService() : BluetoothService {
return this#BluetoothService
}
}
}
private var bluetoothService : BluetoothService? = null
private val serviceConnection: ServiceConnection = object : ServiceConnection {
override fun onServiceConnected(componentName: ComponentName, service:IBinder) {
bluetoothService = (service as LocalBinder).getService()
bluetoothService?.let { bluetooth ->
// ...
}
}
override fun onServiceDisconnected(componentName: ComponentName) {
bluetoothService = null
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val serviceIntent = Intent(this, BluetootService::class.java)
bindService(serviceIntent, serviceConnection, Context.BIND_AUTO_CREATE)
}
See BLE case for the inspiration.

Have you ever tried to use something like dagger? You can create a repository that you istantiate at the start of application.
Then if you need to use it in activity you can inject it with something like this:
#Inject lateinit var bluetoothRepository: BluetoothRepository

Unfortunately, your app has closed (caused by null reference, Bluetooth)

I am trying to create an application using android studio which should connect to my adruino board and send some numbers when pressing some buttons.
Right now I can't solve an error saying that my BluetoothAdapter variable is returning a NULL every time I use it. I tried the application on my phone and it would not run(Unfortunately, your app has closed).
MainActivity.java :
public class MainActivity extends AppCompatActivity {
//variables-not using all of them but some are required in many examples for finding the MAC address
Handler bluetoothIn;
final int handlerState = 0;
private BluetoothAdapter BA;
private BluetoothSocket btSocket = null;
private ConnectedThread mConnectedThread;
private static final UUID BTMODULEUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
//list for addresses
private static final String TAG = "DeviceListActivity";
public static String EXTRA_DEVICE_ADDRESS = "device_address";
private ArrayAdapter<String> mNewDevicesArrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) { //here I define my buttons
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setResult(Activity.RESULT_CANCELED);
final Button Up = (Button) findViewById(R.id.up);
Up.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("1");
}
});
final Button Down = (Button) findViewById(R.id.down);
Down.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("2");
}
});
final Button Right = (Button) findViewById(R.id.right);
Right.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("3");
}
});
final Button Left = (Button) findViewById(R.id.left);
Left.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mConnectedThread.write("4");
}
});
final Button Connect = (Button) findViewById(R.id.connect);
Connect.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
checkBTState();
doDiscovery();
v.setVisibility(View.GONE);
}
});
ArrayAdapter<String> pairedDevicesArrayAdapter =
new ArrayAdapter<String>(this, R.layout.activity_main);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.activity_main);
ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
pairedListView.setAdapter(pairedDevicesArrayAdapter);
pairedListView.setOnItemClickListener(mDeviceClickListener);
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
newDevicesListView.setOnItemClickListener(mDeviceClickListener);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
// Get the local Bluetooth adapter
BA = BluetoothAdapter.getDefaultAdapter();
checkBTState();
if(BA.isEnabled()) {
// Get a set of currently paired devices
Set<BluetoothDevice> pairedDevices = BA.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice device : pairedDevices) {
pairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
String noDevices = getResources().getText(R.string.none_paired).toString();
pairedDevicesArrayAdapter.add(noDevices);
}
}
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException { //something I have seen in one example I tried to copy
return device.createRfcommSocketToServiceRecord(BTMODULEUUID);
//creates secure outgoing connecetion with BT device using UUID
}
#Override
protected void onDestroy() {
super.onDestroy();
// Make sure we're not doing discovery anymore
if (BA != null) {
BA.cancelDiscovery();
}
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}
#Override
public void onResume() {
super.onResume();
/***************************************************/ // code here
BluetoothDevice device = BA.getRemoteDevice(EXTRA_DEVICE_ADDRESS);
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
Toast.makeText(getBaseContext(), "Socket creation failed", Toast.LENGTH_LONG).show();
}
// Establish the Bluetooth socket connection.
try {
btSocket.connect();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
//insert code to deal with this
}
}
mConnectedThread = new ConnectedThread(btSocket);
mConnectedThread.start();
//I send a character when resuming.beginning transmission to check device is connected
//If it is not an exception will be thrown in the write method and finish() will be called
// mConnectedThread.write("x");
}
#Override
public void onPause() {
super.onPause();
try {
//Don't leave Bluetooth sockets open when leaving activity
btSocket.close();
} catch (IOException e2) {
//insert code to deal with this
}
}
private class ConnectedThread extends Thread {
private final InputStream mmInStream;
private final OutputStream mmOutStream;
//creation of the connect thread
public ConnectedThread(BluetoothSocket socket) {
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
//Create I/O streams for connection
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[256];
int bytes;
// Keep looping to listen for received messages
while (true) {
try {
bytes = mmInStream.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;
}
}
}
//write method
public void write(String input) {
byte[] msgBuffer = input.getBytes(); //converts entered String into bytes
try {
mmOutStream.write(msgBuffer); //write bytes over BT connection via outstream
} catch (IOException e) {
//if you cannot write, close the application
Toast.makeText(getBaseContext(), "Connection Failure", Toast.LENGTH_LONG).show();
finish();
}
}
}
private void doDiscovery() {
Log.d(TAG, "doDiscovery()");
// Indicate scanning in the title
setProgressBarIndeterminateVisibility(true);
// If we're already discovering, stop it
if (BA.isDiscovering()) {
BA.cancelDiscovery();
}
// Request discover from BluetoothAdapter
BA.startDiscovery();
}
/**
* The on-click listener for all devices in the ListViews
*/
private AdapterView.OnItemClickListener mDeviceClickListener
= new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
// Cancel discovery because it's costly and we're about to connect
BA.cancelDiscovery();
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
// Create the result Intent and include the MAC address
Intent intent = new Intent();
intent.putExtra(EXTRA_DEVICE_ADDRESS, address);
// Set result and finish this Activity
setResult(Activity.RESULT_OK, intent);
finish();
}
};
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// If it's already paired, skip it, because it's been listed already
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
private void checkBTState() {
// Check device has Bluetooth and that it is turned on
BA=BluetoothAdapter.getDefaultAdapter();
if(BA==null) {
Toast.makeText(getBaseContext(), "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
} else {
if (BA.isEnabled()) {
Log.d(TAG, "...Bluetooth ON...");
} else {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}
}
Logcat:
com.example.mihaianca.helloword, PID: 13051
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mihaianca.helloword/com.example.mihaianca.helloword.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isEnabled()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isEnabled()' on a null object reference
at com.example.mihaianca.helloword.MainActivity.onCreate(MainActivity.java:113)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
I/Process: Sending signal. PID: 13051 SIG: 9
Thank you !

You could try to get a bluetooth adapter like this:
BluetoothManager bluetoothManager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter bluetoothAdapter = bluetoothManager.getAdapter();
I'm using it this way and it's working fine.

How do I initiate my BluetoothHandler to another (several) activity?

I'm making a OBDII Bluetooth Android app and i'm having some issues sending out commands. I've already made a successfully connection between my mobile device and my OBDII adapter, but when I click on another activity, the Bluetooth connection seems to quit?
When you open up the app you'll see a button that says "Connect Device". When you press that, a ListAdapter will show up with paired Bluetooth devices. Then when you have succesfully connected to the device (OBDII Adapter) it will take you to another layout where there is 3 activities that are 3 different powerplatforms for cars. This is where the problem occurs. For now, I just want to be able to read the voltage from the OBDII. But when I click my button getValue inside one of the 3 activities. I get an logcat error. And I think it's because I haven't initiated my BluetoothHandler properly. I have no idea how to do this.
MainActivity:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
Button b1;
BluetoothAdapter mAdapter;
FragmentHostCallback mHost;
BTHandler btHandler;
private Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case Constants.MESSAGE_STATE_CHANGE:
switch (msg.arg1) {
case BTHandler.STATE_CONNECTED:
//setContentView(R.layout.activity_connected);
Intent intent = new Intent(MainActivity.this, Connected.class);
startActivity(intent);
Toast.makeText(getApplicationContext(), R.string.title_connected_to, Toast.LENGTH_SHORT).show();
Log.v("Log", "Connected");
break;
case BTHandler.STATE_NONE:
Toast.makeText(getApplicationContext(), R.string.title_not_connected, Toast.LENGTH_SHORT).show();
break;
}
}
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btHandler = new BTHandler(MainActivity.this, mHandler);
b1 = (Button) findViewById(R.id.connect);
b1.setOnClickListener(this);
mAdapter = BluetoothAdapter.getDefaultAdapter();
//init();
if (mAdapter == null) {
Toast.makeText(getApplicationContext(), R.string.device_not_supported, Toast.LENGTH_LONG).show();
finish();
} else {
if (!mAdapter.isEnabled()) {
Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(intent, 1);
}
}
//BTHandler btHandler = new BTHandler(MainActivity.this, mHandler);
//btHandler.connect("");
}
public void onClick(View v) {
int id = v.getId();
//String voltage = ("ATRV");
switch (id) {
case R.id.connect:
onConnect(); //Operation
Log.v("Log", "Pressed onClick");
break;
/*case R.id.getValue:
btHandler.write(voltage);
Log.v("Log", "getValue" + voltage);
break;*/
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_CANCELED) {
Toast.makeText(getApplicationContext(), R.string.enable_bluetooth, Toast.LENGTH_SHORT).show();
finish();
}
}
private void onConnect() {
ArrayList deviceStrs = new ArrayList();
final ArrayList<String> devices = new ArrayList();
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
Set pairedDevices = mAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
for (Object device : pairedDevices) {
BluetoothDevice bdevice = (BluetoothDevice) device;
deviceStrs.add(bdevice.getName() + "\n" + bdevice.getAddress());
devices.add(bdevice.getAddress());
}
}
// show list
final AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.select_dialog_singlechoice,
deviceStrs.toArray(new String[deviceStrs.size()]));
alertDialog.setSingleChoiceItems(adapter, -1, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
int position = ((AlertDialog) dialog).getListView().getCheckedItemPosition();
String deviceAddress = devices.get(position);
btHandler.connect(deviceAddress);
//btHandler.write();
}
});
alertDialog.setTitle("Paired devices");
alertDialog.show();
}
BTHandler:
public class BTHandler {
public static final int STATE_NONE = 0; // we're doing nothing
public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection
public static final int STATE_CONNECTED = 3; // now connected to a remote device
final ArrayList<String> devices = new ArrayList();
private final Handler mHandler;
private BluetoothAdapter mAdapter;
private BluetoothDevice device;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private BluetoothSocket socket;
private String status;
private int mState;
private boolean connectionStatus = false;
public BTHandler(Context context, Handler handler) { // Konstruktor
mAdapter = BluetoothAdapter.getDefaultAdapter();
mHandler = handler;
}
public void write(String s) {
mConnectedThread.sendRawCommand(s);
Log.v("write", "write");
}
/*
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) {
}
}
*/
public void connect(String deviceAddress) {
mConnectThread = new ConnectThread(deviceAddress);
mConnectThread.start();
}
private void guiHandler(int what, int arg1, String obj) {
Message msg = mHandler.obtainMessage();
msg.what = what;
msg.obj = obj;
msg.arg1 = arg1;
msg.sendToTarget();
}
private class ConnectThread extends Thread {
BluetoothSocket tmp = null;
private BluetoothSocket mmSocket;
public ConnectThread(String deviceAddress) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
device = mAdapter.getRemoteDevice(deviceAddress);
BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
BluetoothDevice device = mAdapter.getRemoteDevice(deviceAddress);
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
try {
tmp = device.createRfcommSocketToServiceRecord(uuid);
//socket.connect();
//Log.v("connect", "connect");
} catch (IOException e) {
//e.printStackTrace();
//Log.v("exception", "e");
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mAdapter.cancelDiscovery();
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes;
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.v("connect", "connect");
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
Log.v("close", "close");
} catch (IOException closeException) {
}
guiHandler(Constants.TOAST, Constants.SHORT, "Connection Failed");
return;
}
guiHandler(Constants.CONNECTION_STATUS, Constants.STATE_CONNECTED, "");
mConnectedThread = new ConnectedThread(mmSocket);
mConnectedThread.start();
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private ObdMultiCommand multiCommand;
public ConnectedThread(BluetoothSocket socket) {
connectionStatus = true;
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
try {
//RPMCommand engineRpmCommand = new RPMCommand();
//SpeedCommand speedCommand = new SpeedCommand();
ModuleVoltageCommand voltageCommand = new ModuleVoltageCommand();
while (!Thread.currentThread().isInterrupted()) {
//engineRpmCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
//speedCommand.run(mmInStream, mmOutStream); //(socket.getInputStream(), socket.getOutputStream());
voltageCommand.run(socket.getInputStream(), socket.getOutputStream());
// TODO handle commands result
//Log.d("Log", "RPM: " + engineRpmCommand.getFormattedResult());
//Log.d("Log", "Speed: " + speedCommand.getFormattedResult());
Log.v("Log", "Voltage: " + voltageCommand.getFormattedResult());
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
byte[] buffer = new byte[1024]; // buffer store for the stream
int bytes; // bytes returned from read()
OBDcmds();
// Keep listening to the InputStream until an exception occurs
while (connectionStatus) {
sendMultiCommand();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
// CALL this to MainActivity
public void sendRawCommand(String command) {
try {
new OdbRawCommand(command);
} catch (Exception e) {
Log.v("sendRawCommand", "e");
}
}
private void OBDcmds() { // execute commands
try {
new EchoOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new LineFeedOffCommand().run(socket.getInputStream(), socket.getOutputStream());
new TimeoutCommand(100).run(socket.getInputStream(), socket.getOutputStream());
new SelectProtocolCommand(ObdProtocols.AUTO).run(socket.getInputStream(), socket.getOutputStream()); //ISO_15765_4_CAN
} catch (Exception e) {
Log.v("OBDcmds", "e");
// handle errors
}
}
/*
// 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) {
}
}
public void sendMultiCommand() {
try {
// RUN some code here
} catch (Exception e) {
}
}
}
}
SPA: One of the power platforms mentioned before.
public class SPA extends AppCompatActivity implements View.OnClickListener {
Button b2;
BTHandler btHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sp);
b2 = (Button) findViewById(R.id.getValue);
b2.setOnClickListener(this);
}
public void onClick(View v) {
int id = v.getId();
String voltage = ("AT RV");
switch (id) {
case R.id.getValue:
btHandler.write(voltage);
Log.v("Log", "getValue" + voltage);
break;
}
}
}
Logcat:

The reason of the error is here:
BTHandler btHandler;
and you are doing this:
btHandler.write(voltage);
but the object is null referenced....
you need to initialize the BTHandler in the oncreate...
or maybe better:
use a service so you can Bind all the activities to that...
PS:
Note that the BTHandler of the MainActivity is not the same as the one declared in the SPA Class... so although that btHandler is constructed and works in MainActivity doesnt mean it will work in other activities/classes

Connect bluetooth from android to computer(paired devices)

So, i want my application to connect to my pc and then use android as a touch pad. Iv been doing a lot of research on the net, but I didn't find anywhere how to exactly connect my phone to pc. I made the pair device function and everything else, I just need the connection method, or at least how could it be done. Here is the code:
public class MainActivity extends Activity {
private BluetoothAdapter adapter;
private Intent turnOn;
private Set<BluetoothDevice> pairedDevices;
private ListView lv;
private Button on,off,pairedDevice,discoverable,nearDevices;
private List<BluetoothDevice> discoveredDevices = new ArrayList<BluetoothDevice>();
private Handler mHandler;
private static final UUID MY_UUID = UUID.fromString("04c6093b-0000-1000-8000-00805f9b34fb");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initialize();
buttonFunc();
find();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void lista(int i){
if(i==0) {
final DeviceAdapter deviceAdapter = new DeviceAdapter(MainActivity.this, discoveredDevices);
lv.setAdapter(deviceAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
pairDevice(deviceAdapter.getItem(position));
Message.message(MainActivity.this, deviceAdapter.getItem(position).getName().toString());
}
});
}
else if(i == 1){
List<BluetoothDevice> vecUpareni = new ArrayList<BluetoothDevice>();
for (BluetoothDevice bt:adapter.getBondedDevices()){
vecUpareni.add(bt);
}
final DeviceAdapter deviceAdapter = new DeviceAdapter(MainActivity.this, vecUpareni);
lv.setAdapter(deviceAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String adresa = deviceAdapter.getItem(position).getAddress();
Method connect = getConnectMethod();
BluetoothDevice device = deviceAdapter.getItem(position);
}
});
}
}
private Method getConnectMethod () {
try {
return BluetoothA2dp.class.getDeclaredMethod("connect", BluetoothDevice.class);
} catch (NoSuchMethodException ex) {
Message.message(MainActivity.this , "Unable to connect");
return null;
}
}
private void pairDevice(BluetoothDevice device) {
try {
Log.d("pairDevice()", "Start Pairing...");
Method m = device.getClass().getMethod("createBond", (Class[]) null);
m.invoke(device, (Object[]) null);
Log.d("pairDevice()", "Pairing finished.");
} catch (Exception e) {
Log.e("pairDevice()", e.getMessage());
}
}
public void buttonFunc(){
on.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn,0);
Message.message(MainActivity.this , "Bluetooth enabled");
}
});
off.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
adapter.disable();
}
});
pairedDevice.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
lista(1);
}
});
discoverable.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 1);
startActivity(discoverableIntent);
}
});
nearDevices.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
lista(0);
}
});
}
public void find(){
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
adapter.startDiscovery();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
//discovery starts, we can show progress dialog or perform other tasks
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
//discovery finishes, dismis progress dialog
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
//bluetooth device found
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
discoveredDevices.add(device);
Message.message(MainActivity.this, "Found device " + device.getName());
lista(0);
}
}
};
public void initialize(){
on = (Button) findViewById(R.id.ON);
off = (Button) findViewById(R.id.OFF);
pairedDevice = (Button) findViewById(R.id.pairedDevices);
nearDevices = (Button) findViewById(R.id.nearDevices);
discoverable = (Button) findViewById(R.id.makeDiscoverable);
lv = (ListView) findViewById(R.id.listaUredjaja);
adapter = BluetoothAdapter.getDefaultAdapter();
if(adapter == null){
System.out.close();
}
if(adapter.isEnabled()){
Message.message(MainActivity.this , "Enabled");
}
else{
Message.message(MainActivity.this , "Not enabled");
}
}
}
And here is the server that is on my pc that is awaiting connection:
public class Mejn {
//start server
private void startServer() throws IOException{
//Create a UUID for SPP
UUID uuid = new UUID("1101", true);
//Create the servicve url
String connectionString = "btspp://localhost:" + uuid +";name=Sample SPP Server";
//open server url
StreamConnectionNotifier streamConnNotifier = (StreamConnectionNotifier)Connector.open( connectionString );
//Wait for client connection
System.out.println("\nServer Started. Waiting for clients to connect...");
StreamConnection connection=streamConnNotifier.acceptAndOpen();
RemoteDevice dev = RemoteDevice.getRemoteDevice(connection);
System.out.println("Remote device address: "+dev.getBluetoothAddress());
System.out.println("Remote device name: "+dev.getFriendlyName(true));
//read string from spp client
InputStream inStream=connection.openInputStream();
BufferedReader bReader=new BufferedReader(new InputStreamReader(inStream));
String lineRead=bReader.readLine();
System.out.println(lineRead);
//send response to spp client
OutputStream outStream=connection.openOutputStream();
PrintWriter pWriter=new PrintWriter(new OutputStreamWriter(outStream));
pWriter.write("Response String from SPP Server\r\n");
pWriter.flush();
pWriter.close();
streamConnNotifier.close();
}
public static void main(String[] args) throws IOException {
//display local device address and name
LocalDevice localDevice = LocalDevice.getLocalDevice();
System.out.println("Address: "+localDevice.getBluetoothAddress());
System.out.println("Name: "+localDevice.getFriendlyName());
Mejn sampleSPPServer=new Mejn();
sampleSPPServer.startServer();
}
}

So, while looking more, found this somewhere and put it in my code, here is the code:
public class MainActivity extends Activity {
private BluetoothAdapter adapter;
private Intent turnOn;
private Set<BluetoothDevice> pairedDevices;
private ListView lv;
private Button on,off,pairedDevice,discoverable,nearDevices;
private List<BluetoothDevice> discoveredDevices = new ArrayList<BluetoothDevice>();
private BluetoothSocket btSocket = null;
public OutputStream outStream;
private static final UUID MY_UUID =
UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private static String address = "C01885BD823C";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initialize();
buttonFunc();
find();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void lista(int i){
if(i==0) {
final DeviceAdapter deviceAdapter = new DeviceAdapter(MainActivity.this, discoveredDevices);
lv.setAdapter(deviceAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
pairDevice(deviceAdapter.getItem(position));
Message.message(MainActivity.this, deviceAdapter.getItem(position).getName().toString());
}
});
}
else if(i == 1){
List<BluetoothDevice> vecUpareni = new ArrayList<BluetoothDevice>();
for (BluetoothDevice bt:adapter.getBondedDevices()){
vecUpareni.add(bt);
}
final DeviceAdapter deviceAdapter = new DeviceAdapter(MainActivity.this, vecUpareni);
lv.setAdapter(deviceAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
BluetoothDevice device = adapter.getRemoteDevice(deviceAdapter.getItem(position).getAddress());
try {
btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
Message.message(MainActivity.this , "In onResume() and socket create failed: " + e.toString() + ".");
}
adapter.cancelDiscovery();
try {
btSocket.connect();
System.out.print("\n...Connection established and data link opened...");
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
Message.message(MainActivity.this , "In onResume() and unable to close socket during connection failure" + e2.getMessage().toString() + ".");
}
}
try {
outStream = btSocket.getOutputStream();
} catch (IOException e) {
Message.message(MainActivity.this , "In onResume() and output stream creation failed:" + e.getMessage() + ".");
}
System.out.print("\n...Sending message to server...");
String message = "Hello from Android.\n";
System.out.print("\n\n...The message that we will send to the server is: "+message);
byte[] msgBuffer = message.getBytes();
try {
outStream.write(message.getBytes());
} catch (IOException e) {
String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
if (address.equals("00:00:00:00:00:00"))
msg = msg + ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address on line 37 in the java code";
msg = msg + ".\n\nCheck that the SPP UUID: " + MY_UUID.toString() + " exists on server.\n\n";
Message.message(MainActivity.this , msg);
}
}
});
}
}
private Method getConnectMethod () {
try {
return BluetoothA2dp.class.getDeclaredMethod("connect", BluetoothDevice.class);
} catch (NoSuchMethodException ex) {
Message.message(MainActivity.this , "Unable to connect");
return null;
}
}
private void pairDevice(BluetoothDevice device) {
try {
Log.d("pairDevice()", "Start Pairing...");
Method m = device.getClass().getMethod("createBond", (Class[]) null);
m.invoke(device, (Object[]) null);
Log.d("pairDevice()", "Pairing finished.");
} catch (Exception e) {
Log.e("pairDevice()", e.getMessage());
}
}
public void buttonFunc(){
on.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
turnOn = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOn,0);
Message.message(MainActivity.this , "Bluetooth enabled");
}
});
off.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
adapter.disable();
}
});
pairedDevice.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
lista(1);
}
});
discoverable.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 1);
startActivity(discoverableIntent);
}
});
nearDevices.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
lista(0);
}
});
}
public void find(){
IntentFilter filter = new IntentFilter();
filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
registerReceiver(mReceiver, filter);
adapter.startDiscovery();
}
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
//discovery starts, we can show progress dialog or perform other tasks
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
//discovery finishes, dismis progress dialog
} else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
//bluetooth device found
BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
discoveredDevices.add(device);
Message.message(MainActivity.this, "Found device " + device.getName());
lista(0);
}
}
};
public void initialize(){
on = (Button) findViewById(R.id.ON);
off = (Button) findViewById(R.id.OFF);
pairedDevice = (Button) findViewById(R.id.pairedDevices);
nearDevices = (Button) findViewById(R.id.nearDevices);
discoverable = (Button) findViewById(R.id.makeDiscoverable);
lv = (ListView) findViewById(R.id.listaUredjaja);
adapter = BluetoothAdapter.getDefaultAdapter();
if(adapter == null){
System.out.close();
}
if(adapter.isEnabled()){
Message.message(MainActivity.this , "Enabled");
}
else{
Message.message(MainActivity.this , "Not enabled");
}
}
}
And code for server:
/**
* Class that implements an SPP Server which accepts single line of
* message from an SPP client and sends a single line of response to the client.
*/
public class Mejn {
//start server
private void startServer() throws IOException{
//Create a UUID for SPP
UUID uuid = new UUID("1101", true);
//Create the servicve url
String connectionString = "btspp://localhost:" + uuid +";name=Sample SPP Server";
//open server url
StreamConnectionNotifier streamConnNotifier = (StreamConnectionNotifier)Connector.open( connectionString );
//Wait for client connection
System.out.println("\nServer Started. Waiting for clients to connect...");
StreamConnection connection=streamConnNotifier.acceptAndOpen();
RemoteDevice dev = RemoteDevice.getRemoteDevice(connection);
System.out.println("Remote device address: "+dev.getBluetoothAddress());
System.out.println("Remote device name: "+dev.getFriendlyName(true));
//read string from spp client
InputStream inStream=connection.openInputStream();
BufferedReader bReader=new BufferedReader(new InputStreamReader(inStream));
String lineRead=bReader.readLine();
System.out.println(lineRead);
//send response to spp client
OutputStream outStream=connection.openOutputStream();
PrintWriter pWriter=new PrintWriter(new OutputStreamWriter(outStream));
pWriter.write("Response String from SPP Server\r\n");
pWriter.flush();
pWriter.close();
streamConnNotifier.close();
}
public static void main(String[] args) throws IOException {
//display local device address and name
LocalDevice localDevice = LocalDevice.getLocalDevice();
System.out.println("Address: "+localDevice.getBluetoothAddress());
System.out.println("Name: "+localDevice.getFriendlyName());
Mejn sampleSPPServer=new Mejn();
sampleSPPServer.startServer();
}
}

outtring initated in BluetoothcommandService.java

I, will be asking how to combine/fuse 2 java files if,the outstring was initiated in the BluetoothcommandService.java file I will be editing my Post sir and post my MainActivity.java file and BluetoothCommandService.java file..I just doent know how to combine it..
this is the MainActivity.java
public class MainActivity extends Activity {
//public class MainActivity extends Activity implements OnClickListener {
BluetoothAdapter BTAdapter;
BluetoothDevice BTDevice;
private TextView title;
private static final int REQUEST_DEVICE_CONNECT = 1;
private static final int REQUEST_ENABLE_BLUETOOTH = 2;
private BluetoothCommandService commandService = null;
private String connectedDeviceName = null;
//Message types sent from the Handler
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_NAME = 4;
public static final int MESSAGE_TOAST = 5;
public static final int RECIEVE_MESSAGE = 6;
//Will be used in BluetoothCommandSrvice jave file
public static final String TOAST = "toast";
public static final String DEVICENAME = "device name";
//#######for the controller
public static final String tagStateCTRL = "Controller";
private OutputStream outStream = null;
private static final UUID myUUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
private static String address = "00:00:00:00:00:00"; // Insert your bluetooth devices MAC address
private StringBuilder sb = new StringBuilder();
Button btn_d1_on, btn_d1_off;
//for changing the device_1 name
TextView device1;
Button change;
EditText renameDevice;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main); gi move sa ubos sa request window
// Set up the window layout
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.activity_main);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.custom_title);
title = (TextView) findViewById(R.id.title_left_text); // Set up the custom title
title.setText(R.string.app_name); // Set up the custom title
title = (TextView) findViewById(R.id.title_right_text); // Set up the custom title
//Button openButton = (Button)findViewById(R.id.open);
//##########for the controller
btn_d1_on = (Button) findViewById(R.id.device1_on);
btn_d1_off = (Button) findViewById(R.id.device1_off);
//########for changing the device_1 name
device1 = (TextView)findViewById(R.id.device1);
change = (Button)findViewById(R.id.buttonTest);
renameDevice = (EditText)findViewById(R.id.editTest);
change.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String change_device1 = renameDevice.getText().toString();
device1.setText(change_device1);
}
});
// AUTO REQUEST OF ENABLING THE BLUETOOTH
BTAdapter = BluetoothAdapter.getDefaultAdapter();
//A code that will detect if BT is enabled otherwise will require it.
if (BTAdapter == null)
{
//Toast.makeText(context, text, duration)
Toast.makeText(this, "No Bluetooth adapter is available.", Toast.LENGTH_LONG).show();
finish();
return;
}
//##########for the controller
btn_d1_on.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//sendData("1");
//Toast msg = Toast.makeText(getBaseContext(), "The device is now On", Toast.LENGTH_SHORT);
//msg.show()
btn_d1_on.setEnabled(false);
sendData("1");
}
});
//##########for the controller
btn_d1_off.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//sendData("0");
//Toast msg = Toast.makeText(getBaseContext(), "The device is now On", Toast.LENGTH_SHORT);
//msg.show();
btn_d1_off.setEnabled(false);
sendData("0");
}
});
}
#Override
protected void onStart() {
super.onStart();
//Requesting Bluetooth automatically when its not yet enabled.
if (!BTAdapter.isEnabled())
{
Intent enableIntent = new Intent (BluetoothAdapter.ACTION_REQUEST_ENABLE);
//startActivityForResult(enableIntent, 0);
startActivityForResult(enableIntent, REQUEST_ENABLE_BLUETOOTH);
}
else
{
if (commandService == null)
setupCommand();
}
}
//if (BTAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE)
//{
//Intent discoverableIntent = new Intent (BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
//discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 500);
//startActivity(discoverableIntent);
//}
#Override
protected void onResume() {
super.onResume();
if (commandService != null)
{
if (commandService.getState() == BluetoothCommandService.stateNothing)
{
commandService.start();
}
}
}
private void setupCommand()
{
commandService = new BluetoothCommandService(this, bluetoothHandler);
}
#Override
protected void onDestroy()
{
super.onDestroy();
if (commandService != null)
commandService.stop();
}
private void ensureDiscoverable()
{
//Get the current Bluetooth scan mode of the local Bluetooth adapter. The Bluetooth scan mode determines if the local adapter is connectable and/or discoverable from remote Bluetooth devices.
if (BTAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE)
{
Intent ensureDiscoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
ensureDiscoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(ensureDiscoverableIntent);
}
}
//This gets information back from the "BluetoothChatService"/"BluetoothCommandService"
//#SuppressLint("HandlerLeak")
//private final Handler bluetoothHandler = new Handler(new Handler.Callback()
#SuppressLint("HandlerLeak")
public final Handler bluetoothHandler = new Handler()
{
#Override
public void handleMessage(android.os.Message msg)
{
switch (msg.what)
{
case MESSAGE_STATE_CHANGE:
switch (msg.arg1)
{
case BluetoothCommandService.stateConnected:
title.setText(R.string.title_connectedTo);
title.append(connectedDeviceName);
break;
case BluetoothCommandService.stateConnecting:
title.setText(R.string.title_connecting);
break;
case BluetoothCommandService.stateListen:
case BluetoothCommandService.stateNothing:
title.setText(getString(R.string.title_notConnected));
break;
}
break;
case MESSAGE_DEVICE_NAME:
connectedDeviceName = msg.getData().getString(DEVICENAME);
Toast.makeText(getApplicationContext(), "Connected to " + connectedDeviceName, Toast.LENGTH_SHORT).show();
break;
case MESSAGE_TOAST:
Toast.makeText(getApplicationContext(), msg.getData().getString(TOAST), Toast.LENGTH_SHORT).show();
break;
case RECIEVE_MESSAGE: // if receive message
byte[] readBuf = (byte[]) msg.obj;
String strIncom = new String(readBuf, 0, msg.arg1); // create string from bytes array
sb.append(strIncom); // append string
int endOfLineIndex = sb.indexOf("\r\n"); // determine the end-of-line
if (endOfLineIndex > 0) { // if end-of-line,
//String sbprint = sb.substring(0, endOfLineIndex); // extract string
sb.delete(0, sb.length()); // and clear
//txtArduino.setText("Data from Arduino: " + sbprint); // update TextView
//1/4/14
btn_d1_on.setEnabled(true);
btn_d1_off.setEnabled(true);
}
//Log.d(TAG, "...String:"+ sb.toString() + "Byte:" + msg.arg1 + "...");
break;
}
//return false;
}
};
//});
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_DEVICE_CONNECT:
// When DeviceList Activity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
// Get the device MAC address
String address = data.getExtras()
.getString(DeviceList.EXTRA_DEVICE_MAC_ADDRESS);
// Get the BLuetoothDevice object
BluetoothDevice device = BTAdapter.getRemoteDevice(address);
// Attempt to connect to the device
commandService.connect(device);
}
break;
case REQUEST_ENABLE_BLUETOOTH:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
setupCommand();
} else {
// User did not enable Bluetooth or an error occured
Toast.makeText(this, R.string.notEnabledBluetooth, Toast.LENGTH_SHORT).show();
finish();
}
}
}
#Override
//Creating an Option Menu for connectivity and discoverability of a BT device
public boolean onCreateOptionsMenu(Menu menu)
{
//MenuInflater is a class
MenuInflater OptionMenu = getMenuInflater();
//OptionMenu.inflate(menuRes, menu)
OptionMenu.inflate(R.menu.main, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.connect:
Intent serverIntent = new Intent(this, DeviceList.class);
//this.startActivityForResult(serverIntent, REQUEST_DEVICE_CONNECT);
startActivityForResult(serverIntent, REQUEST_DEVICE_CONNECT);
return true;
case R.id.discoverable:
ensureDiscoverable();
return true;
//case R.id.abouts:
//Intent intentabouts = new Intent(this,abouts.class);
//return true;
//default:
//return super.onOptionsItemSelected(item);
}
return false;
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_VOLUME_UP)
{
commandService.write(BluetoothCommandService.VOL_UP);
return true;
}
else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)
{
commandService.write(BluetoothCommandService.VOL_DOWN);
return true;
}
return super.onKeyDown(keyCode, event);
}
//#########################################
private void sendData(String message)
//public void sendData(String message)
{
byte[] msgBuffer = message.getBytes();
Log.d(tagStateCTRL, "...Sending data: " + message + "...");
try {
outStream.write(msgBuffer);
}
catch (IOException e){
String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
if (address.equals("00:00:00:00:00:00"))
msg = msg + ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address in the java code";
msg = msg + ".\n\nCheck that the SPP UUID: " + myUUID.toString() + " exists on server.\n\n";
errorExit("Fatal Error", msg);
}
}
private void errorExit(String title, String message){
Toast msg = Toast.makeText(getBaseContext(),
title + " - " + message, Toast.LENGTH_SHORT);
msg.show();
finish();
}
//#########################################
}
This is the BluetoothCommanService.java
public class BluetoothCommandService {
private final BluetoothAdapter BTAdapter;
private final Handler bluetoothHandler;
private int connectionState;
private ConnectThread connectThread;
//private ConnectedThread connectedThread;
public ConnectedThread connectedThread;
//***Added 12/27/13
private AcceptThread mainAcceptThread;
//connection states of the Bluetooth
public static final int stateNothing = 0; //doing nothing
public static final int stateListen = 1; //listening for incoming connections
public static final int stateConnecting = 2; //initiating an outgoing connection
public static final int stateConnected = 3;
//constants that indicate command to computer
public static final int exitCMD = -1;
public static final int VOL_UP = 1;
public static final int VOL_DOWN = 2;
private static final boolean D = true;
private static final String tagState = "BluetoothCommandService";
//universally unique identifier (UUID)
//The intent of UUIDs is to enable distributed systems to uniquely identify information without significant central coordination
//private static final UUID myUUID = UUID.fromString("04c6093b-0000-1000-8000-00805f9b34fb");
private static final UUID myUUID = UUID.fromString("fa87c0d0-afac-11de-8a39-0800200c9a66");
//Name for the SDP (don;t know what is it) record when creating server socket
private static final String name = "BluetoothCommand";
public BluetoothCommandService(Context context, Handler handler) { // context == UI Activity Context && handler == send message back to the UI Activity
BTAdapter = BluetoothAdapter.getDefaultAdapter();
connectionState = stateNothing;
bluetoothHandler = handler;
}
private synchronized void setState(int state) { // state == current connection state; an integer
if (D) Log.d(tagState, "setState() " + connectionState + " -> " + state);
connectionState = state;
//Give the new state to the Handler so that the UI Activity can update
//bluetoothHandler.obtainMessage(what, arg1, arg2)
bluetoothHandler.obtainMessage(MainActivity.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
}
public synchronized int getState() { //return the current connection state
return connectionState;
}
public synchronized void start() {
if (D) Log.d(tagState, "start");
// Cancel any thread attempting to make a connection
if (connectThread != null)
{
connectThread.cancel();
connectThread = null;
}
// Cancel any thread currently running a connection
if (connectedThread != null)
{
connectedThread.cancel();
connectedThread = null;
}
// Start the thread to listen on a BluetoothServerSocket
if (mainAcceptThread == null)
{
mainAcceptThread = new AcceptThread();
mainAcceptThread.start();
}
setState(stateListen);
}
//device == the BluetoothDevice to connect
public synchronized void connect(BluetoothDevice device) {
if (D) Log.d(tagState, "connect to: " + device);
// Cancel any thread attempting to make a connection
if (connectionState == stateConnecting) {
if (connectThread != null)
{
connectThread.cancel();
connectThread = null;
}
}
// Cancel any thread currently running a connection
if (connectedThread != null)
{
connectedThread.cancel();
connectedThread = null;
}
// Cancel the accept thread because we only want to connect to one device
if (mainAcceptThread != null)
{
mainAcceptThread.cancel();
mainAcceptThread = null;
}
// Start the thread to connect with the given device
connectThread = new ConnectThread(device);
connectThread.start();
setState(stateConnecting);
}
public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) {
if (D) Log.d(tagState, "connected");
// Cancel the thread that completed the connection
if (connectThread != null)
{
connectThread.cancel();
connectThread = null;
}
// Cancel any thread currently running a connection
if (connectedThread != null)
{
connectedThread.cancel();
connectedThread = null;
}
if (mainAcceptThread != null)
{
mainAcceptThread.cancel();
mainAcceptThread = null;
}
// Start the thread to manage the connection and perform transmissions
connectedThread = new ConnectedThread(socket);
connectedThread.start();
Message msg = bluetoothHandler.obtainMessage(MainActivity.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(MainActivity.DEVICENAME, device.getName());
msg.setData(bundle);
bluetoothHandler.sendMessage(msg);
setState(stateConnected);
}
public synchronized void stop() {
if (D) Log.d(tagState, "stop");
if (connectThread != null)
{
connectThread.cancel();
connectThread = null;
}
if (connectedThread != null)
{
connectedThread.cancel();
connectedThread = null;
}
if (mainAcceptThread != null)
{
mainAcceptThread.cancel();
mainAcceptThread = null;
}
setState(stateNothing);
}
public void write(byte[] out) {
ConnectedThread r;
synchronized (this) {
if (connectionState != stateConnected) return;
r = connectedThread;
}
r.write(out);
}
public void write(int out) {
// Create temporary object
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (connectionState != stateConnected) return;
r = connectedThread;
}
// Perform the write unsynchronized
r.write(out);
}
private void connectionFailed() {
setState(stateListen);
// Send a failure message back to the Activity
Message msg = bluetoothHandler.obtainMessage(MainActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(MainActivity.TOAST, "Unable to connect device");
msg.setData(bundle);
bluetoothHandler.sendMessage(msg);
}
/**
* Indicate that the connection was lost and notify the UI Activity.
*/
private void connectionLost() {
setState(stateListen);
Message msg = bluetoothHandler.obtainMessage(MainActivity.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(MainActivity.TOAST, "Device connection was lost");
msg.setData(bundle);
bluetoothHandler.sendMessage(msg);
}
private class ConnectThread extends Thread {
private final BluetoothSocket connectThread_socket;
private final BluetoothDevice connectThread_device;
public ConnectThread(BluetoothDevice device) {
connectThread_device = device;
BluetoothSocket tmp = null;
//Get a BluetoothSocket for a connection w/ the given BT device
//try {
//catch (IOException e) {
//Log.e(tag, msg, tr)
//Log.e(tagState, "create() failed", e);}
//Added 12/28/13
Method m;
try {
m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
tmp = (BluetoothSocket) m.invoke(device, 1);
} catch (SecurityException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (NoSuchMethodException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
connectThread_socket = tmp;
}
public void run() {
Log.i(tagState, "BEGIN ConnectThread");
setName("ConnectThread");
BTAdapter.cancelDiscovery();
// Make a connection to the BluetoothSocket
try {
connectThread_socket.connect();}
catch (IOException e) {
connectionFailed();
try {
connectThread_socket.close();
} catch (IOException e2) {
Log.e(tagState, "Unable to close() socket during connection failure", e2);
}
BluetoothCommandService.this.start();
return;
}
// Reset the ConnectThread because we're done
synchronized (BluetoothCommandService.this) {
connectThread = null;
}
// Start the connected thread
connected(connectThread_socket, connectThread_device); //ERROR: will still create "connected"
}
public void cancel() {
try {
connectThread_socket.close();
} catch (IOException e) {
Log.e(tagState, "close() of connect socket failed", e);
}
}
}
private class ConnectedThread extends Thread {
private final BluetoothSocket connectedThread_socket;
private final InputStream connectedThread_inStream;
private final OutputStream connectedThread_outStream;
public ConnectedThread(BluetoothSocket socket) {
Log.d(tagState, "create ConnectedThread");
connectedThread_socket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the BluetoothSocket input and output streams
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
Log.e(tagState, "temp sockets not created", e);
}
connectedThread_inStream = tmpIn;
connectedThread_outStream = tmpOut;
}
public void run() {
Log.i(tagState, "BEGIN ConnectedThread");
byte[] buffer = new byte[1024]; // WALA JUD KO KASABOT ANI MAN :D
while (true) {
try {
int bytes = connectedThread_inStream.read(buffer);
bluetoothHandler.obtainMessage(MainActivity.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(tagState, "disconnected", e);
connectionLost(); //ERROR: will still create "private void CONNECTIONLOST"
break;
}
}
}
public void write(byte[] buffer) {
try {
connectedThread_outStream.write(buffer);
} catch (IOException e) {
Log.e(tagState, "Exception during write", e);
}
}
public void write(int out) {
try {
connectedThread_outStream.write(out);
} catch (IOException e) {
Log.e(tagState, "Exception during write", e);
}
}
public void cancel() {
try {
connectedThread_outStream.write(exitCMD);
connectedThread_socket.close();
} catch (IOException e) {
Log.e(tagState, "close() of connect socket failed", e);
}
}
}
private class AcceptThread extends Thread {
// The local server socket
private final BluetoothServerSocket acceptThread_ServerSocket;
public AcceptThread() {
BluetoothServerSocket tmp = null;
// Create a new listening server socket
try {
tmp = BTAdapter.listenUsingRfcommWithServiceRecord(name, myUUID);
} catch (IOException e) {
Log.e(tagState, "listen() failed", e);
}
acceptThread_ServerSocket = tmp;
}
public void run() {
if (D) Log.d(tagState, "BEGIN mainAcceptThread" + this);
setName("AcceptThread");
BluetoothSocket socket = null;
while (connectionState != stateConnected) {
try {
socket = acceptThread_ServerSocket.accept();
} catch (IOException e) {
Log.e(tagState, "accept() failed", e);
break;
}
if (socket != null) {
synchronized (BluetoothCommandService.this) {
switch (connectionState) {
case stateListen:
case stateConnecting:
connected(socket, socket.getRemoteDevice());
break;
case stateNothing:
case stateConnected:
try {
socket.close();
} catch (IOException e) {
Log.e(tagState, "Could not close unwanted socket", e);
}
break;
}
}
}
}
if (D) Log.i(tagState, "END mainAcceptThread");
}
public void cancel() {
if (D) Log.d(tagState, "cancel " + this);
try {
acceptThread_ServerSocket.close();
} catch (IOException e) {
Log.e(tagState, "close() of server failed", e);
}
}
}
}