How to detect and print from the USB printer from android

I'm creating an android app(API level 16 minimum) that could print a document from my android device, where printer is connected through USB. I found a code to detect USBfrom this link. I've attached my printer(HP Laserjet P1007) through USB. But it is not able to detect printer. Edited I've made some progress in detecting printer. I am able to detect printer. But still i am not able to print via bulk transfer. I've also tried to asynchronous transfer using method `usbRequest.queue` And here's my code ``` public class MainActivity extends Activity { private final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION"; PendingIntent mPermissionIntent; UsbManager usbManager; UsbDevice device; UsbDevice printer = null; private static final int PRINTER_VENDOR_ID = 1008; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { setContentView(R.layout.activity_main); Log.i("Info", "Activity started"); usbManager = (UsbManager) getSystemService(Context.USB_SERVICE); HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList(); if (deviceList.size() <= 0) { Log.i("Info", "No device found"); } else { Log.i("Info", "Number of device : " + deviceList.size()); ((TextView) findViewById(R.id.deviceCount)) .setText("No of device : " + deviceList.size()); } Iterator<UsbDevice> deviceIterator = deviceList.values().iterator(); int count = 0; mPermissionIntent = PendingIntent.getBroadcast(getBaseContext(), 0, new Intent(ACTION_USB_PERMISSION), 0); while (deviceIterator.hasNext()) { count++; device = deviceIterator.next(); Log.i("info", "Device No " + count + "........"); Log.i("info", "Vendor id : " + device.getVendorId()); Log.i("info", "Product id : " + device.getProductId()); Log.i("info", "Device name : " + device.getDeviceName()); Log.i("info", "Device class : " + device.getClass().getName()); Log.i("info", "Device protocol: " + device.getDeviceProtocol()); Log.i("info", "Device subclass : " + device.getDeviceSubclass()); if (device.getVendorId() == PRINTER_VENDOR_ID) { printer = device; break; } } findViewById(R.id.buttonPrint).setOnClickListener( new OnClickListener() { @Override public void onClick(View v) { Log.i("Info", "Print command given"); IntentFilter filter = new IntentFilter( ACTION_USB_PERMISSION); registerReceiver(mUsbReceiver, filter); if (printer != null) { usbManager.requestPermission(printer, mPermissionIntent); } else { Log.e("Exception", "Printer not found"); } } }); } catch (Exception e) { Log.e("Exception", "Exception in onCreate " + e.getMessage()); e.printStackTrace(); } } private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { try { String action = intent.getAction(); if (ACTION_USB_PERMISSION.equals(action)) { synchronized (this) { final UsbDevice printerDevice = (UsbDevice) intent .getParcelableExtra(UsbManager.EXTRA_DEVICE); if (intent.getBooleanExtra( UsbManager.EXTRA_PERMISSION_GRANTED, false)) { if (printerDevice != null) { Log.i("Info", "Device permission granted"); startPrinting(printerDevice); } } else { Log.d("Debug", "permission denied for device " + printerDevice); } } } } catch (Exception e) { Log.e("Exception", "Exception in onRecieve " + e.getMessage()); e.printStackTrace(); } } }; public void startPrinting(final UsbDevice printerDevice) { new Handler().post(new Runnable() { UsbDeviceConnection conn; UsbInterface usbInterface; @Override public void run() { try { Log.i("Info", "Bulk transfer started"); usbInterface = printerDevice.getInterface(0); UsbEndpoint endPoint = usbInterface.getEndpoint(0); conn = usbManager.openDevice(printer); conn.claimInterface(usbInterface, true); String myStringData = "\nThis \nis \nmy \nsample \ntext"; byte[] array = myStringData.getBytes(); ByteBuffer output_buffer = ByteBuffer .allocate(array.length); UsbRequest request = new UsbRequest(); request.initialize(conn, endPoint); request.queue(output_buffer, array.length); if (conn.requestWait() == request) { Log.i("Info", output_buffer.getChar(0) + ""); Message m = new Message(); m.obj = output_buffer.array(); // handler.sendMessage(m); output_buffer.clear(); } else { Log.i("Info", "No request recieved"); } // int transfered = conn.bulkTransfer(endPoint, // myStringData.getBytes(), // myStringData.getBytes().length, 5000); // Log.i("Info", "Amount of data transferred : " + // transfered); } catch (Exception e) { Log.e("Exception", "Unable to transfer bulk data"); e.printStackTrace(); } finally { try { conn.releaseInterface(usbInterface); Log.i("Info", "Interface released"); conn.close(); Log.i("Info", "Usb connection closed"); unregisterReceiver(mUsbReceiver); Log.i("Info", "Brodcast reciever unregistered"); } catch (Exception e) { Log.e("Exception", "Unable to release resources because : " + e.getMessage()); e.printStackTrace(); } } } }); } } ``` And here's the log i'm getting ``` 05-29 11:59:04.627: I/Info(5369): Print command given 05-29 11:59:04.657: I/Info(5369): Device permission granted 05-29 11:59:04.657: I/Info(5369): Bulk transfer started 05-29 11:59:04.657: D/UsbRequestJNI(5369): init 05-29 11:59:04.657: I/Info(5369): ?? 05-29 11:59:04.657: I/Info(5369): Interface released 05-29 11:59:04.657: D/UsbDeviceConnectionJNI(5369): close 05-29 11:59:04.657: I/Info(5369): Usb connection closed 05-29 11:59:04.657: I/Info(5369): Brodcast reciever unregistered ``` But in printer side i'm not getting any response... Thanks in advance for help.