The application gives the users 2 connection options, USB and Bluetooth. USB works fine. I have obtained sample codes for Bluetooth connection, however they are designed to work as activity. I tried to do it in a Service but failed.
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); startService(new Intent(this, MyService.class)); <service android:enabled="true" android:name=".MyService" /> enter code here
I need to establish Bluetooth communication with a device that is already paired and its MAC address is known. So I can skip discovery and pairing phases. The device I am trying to connect is always discoverable and awaiting connection. Is there a way to do this from a Service Class and keep that connection up through other activities?
I am using BluetoothChatService and DeviceListActivity
I have written a Bluetooth services which runs in the background and can communicate to any Activity in the application using Messenger http://developer.android.com/guide/components/bound-services.html.
public class PrinterService extends Service { private BluetoothAdapter mBluetoothAdapter; public static final String BT_DEVICE = "btdevice"; public static final String SPP_UUID = "00001101-0000-1000-8000-00805F9B34FB"; 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 private ConnectThread mConnectThread; private static ConnectedThread mConnectedThread; // public mInHangler mHandler = new mInHangler(this); private static Handler mHandler = null; public static int mState = STATE_NONE; public static String deviceName; public Vector<Byte> packdata = new Vector<Byte>(2048); public static Device device = null; @Override public void onCreate() { Log.d("PrinterService", "Service started"); super.onCreate(); } @Override public IBinder onBind(Intent intent) { mHandler = ((MyAplication) getApplication()).getHandler(); return mBinder; } public class LocalBinder extends Binder { PrinterService getService() { return PrinterService.this; } } private final IBinder mBinder = new LocalBinder(); @Override public int onStartCommand(Intent intent, int flags, int startId) { Log.d("PrinterService", "Onstart Command"); mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (mBluetoothAdapter != null) { device = (Device) intent.getSerializableExtra(BT_DEVICE); deviceName = device.getDeviceName(); String macAddress = device.getMacAddress(); if (macAddress != null && macAddress.length() > 0) { connectToDevice(macAddress); } else { stopSelf(); return 0; } } String stopservice = intent.getStringExtra("stopservice"); if (stopservice != null && stopservice.length() > 0) { stop(); } return START_STICKY; } private synchronized void connectToDevice(String macAddress) { BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(macAddress); if (mState == STATE_CONNECTING) { if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; } } // Cancel any thread currently running a connection if (mConnectedThread != null) { mConnectedThread.cancel(); mConnectedThread = null; } mConnectThread = new ConnectThread(device); mConnectThread.start(); setState(STATE_CONNECTING); } private void setState(int state) { PrinterService.mState = state; if (mHandler != null) { mHandler.obtainMessage(AbstractActivity.MESSAGE_STATE_CHANGE, state, -1).sendToTarget(); } } public synchronized void stop() { setState(STATE_NONE); if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; } if (mConnectedThread != null) { mConnectedThread.cancel(); mConnectedThread = null; } if (mBluetoothAdapter != null) { mBluetoothAdapter.cancelDiscovery(); } stopSelf(); } @Override public boolean stopService(Intent name) { setState(STATE_NONE); if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; } if (mConnectedThread != null) { mConnectedThread.cancel(); mConnectedThread = null; } mBluetoothAdapter.cancelDiscovery(); return super.stopService(name); } private void connectionFailed() { PrinterService.this.stop(); Message msg = mHandler.obtainMessage(AbstractActivity.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString(AbstractActivity.TOAST, getString(R.string.error_connect_failed)); msg.setData(bundle); mHandler.sendMessage(msg); } private void connectionLost() { PrinterService.this.stop(); Message msg = mHandler.obtainMessage(AbstractActivity.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString(AbstractActivity.TOAST, getString(R.string.error_connect_lost)); msg.setData(bundle); mHandler.sendMessage(msg); } private static Object obj = new Object(); public static void write(byte[] out) { // Create temporary object ConnectedThread r; // Synchronize a copy of the ConnectedThread synchronized (obj) { if (mState != STATE_CONNECTED) return; r = mConnectedThread; } // Perform the write unsynchronized r.write(out); } private synchronized void connected(BluetoothSocket mmSocket, BluetoothDevice mmDevice) { // Cancel the thread that completed the connection if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; } // Cancel any thread currently running a connection if (mConnectedThread != null) { mConnectedThread.cancel(); mConnectedThread = null; } mConnectedThread = new ConnectedThread(mmSocket); mConnectedThread.start(); // Message msg = // mHandler.obtainMessage(AbstractActivity.MESSAGE_DEVICE_NAME); // Bundle bundle = new Bundle(); // bundle.putString(AbstractActivity.DEVICE_NAME, "p25"); // msg.setData(bundle); // mHandler.sendMessage(msg); setState(STATE_CONNECTED); } private class ConnectThread extends Thread { private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; public ConnectThread(BluetoothDevice device) { this.mmDevice = device; BluetoothSocket tmp = null; try { tmp = device.createRfcommSocketToServiceRecord(UUID.fromString(SPP_UUID)); } catch (IOException e) { e.printStackTrace(); } mmSocket = tmp; } @Override public void run() { setName("ConnectThread"); mBluetoothAdapter.cancelDiscovery(); try { mmSocket.connect(); } catch (IOException e) { try { mmSocket.close(); } catch (IOException e1) { e1.printStackTrace(); } connectionFailed(); return; } synchronized (PrinterService.this) { mConnectThread = null; } connected(mmSocket, mmDevice); } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e("PrinterService", "close() of connect socket failed", 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; try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { Log.e("Printer Service", "temp sockets not created", e); } mmInStream = tmpIn; mmOutStream = tmpOut; } @Override public void run() { while (true) { try { if (!encodeData(mmInStream)) { mState = STATE_NONE; connectionLost(); break; } else { } // mHandler.obtainMessage(AbstractActivity.MESSAGE_READ, // bytes, -1, buffer).sendToTarget(); } catch (Exception e) { e.printStackTrace(); connectionLost(); PrinterService.this.stop(); break; } } } private byte[] btBuff; public void write(byte[] buffer) { try { mmOutStream.write(buffer); // Share the sent message back to the UI Activity mHandler.obtainMessage(AbstractActivity.MESSAGE_WRITE, buffer.length, -1, buffer).sendToTarget(); } catch (IOException e) { Log.e("PrinterService", "Exception during write", e); } } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e("PrinterService", "close() of connect socket failed", e); } } } public void trace(String msg) { Log.d("AbstractActivity", msg); toast(msg); } public void toast(String msg) { Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_SHORT).show(); } @Override public void onDestroy() { stop(); Log.d("Printer Service", "Destroyed"); super.onDestroy(); } private void sendMsg(int flag) { Message msg = new Message(); msg.what = flag; handler.sendMessage(msg); } private Handler handler = new Handler() { @Override public void handleMessage(Message msg) {// if (!Thread.currentThread().isInterrupted()) { switch (msg.what) { case 3: break; case 4: break; case 5: break; case -1: break; } } super.handleMessage(msg); } }; }
UPDATE
you need to use Handler in your MyApplication Class
Handler.Callback realCallback = null; Handler handler = new Handler() { public void handleMessage(android.os.Message msg) { if (realCallback != null) { realCallback.handleMessage(msg); } }; }; public Handler getHandler() { return handler; } public void setCallBack(Handler.Callback callback) { this.realCallback = callback; }
