Develop Reference

Backgroundservice is running, but not working (FileObserver)

I want to run a Backgroundservice (FileObserver) that will look for any filechanges in the system (CREATE, DELETE, MOVE, ...).
When I start my application it works a few seconds and logs everything fine. For example at taking a picture by the camera it logs that. After a few seconds the service is still listed in Settings => Developer Options => Running Services but does not work and log anything anymore.
Android Version: 7.0
Device: Samsung Galaxy S7 Edge
I copied the code from Niza Siwale's answer here 1:1 and added only the Logs like that :
How to monitor folder for file changes in background?
#Override
public void onEvent(int event, final String path) {
if (event == FileObserver.OPEN) {
Log.v("Event: ", "Open" + path);
} else if (event == FileObserver.CREATE && (!path.equals(".probe"))) {
Log.v("Event: ", "Create" + path);
} else if (event == FileObserver.DELETE_SELF || event == FileObserver.DELETE) {
Log.v("Event: ", "Delete" + path);
} else if (event == FileObserver.MOVE_SELF || event == FileObserver.MOVED_FROM || event == FileObserver.MOVED_TO) {
Log.v("Event: ", "Move" + path);
}
}
Why is the service running in background (as I can see in Running Services) but not donig any logs, if something changes in the filesystem?
Full Code:
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.spicysoftware.phonesaver">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<!-- Adding the permission -->
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<service
android:name=".FileSystemObserverService"
android:enabled="true"
android:exported="true" >
</service>
<!-- Declaring broadcast receiver for BOOT_COMPLETED event. -->
<receiver android:name=".StartupReceiver" android:enabled="true" android:exported="false">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
</intent-filter>
</receiver>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
MainActivity
package com.spicysoftware.phonesaver;
import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Environment;
import android.os.FileObserver;
import android.os.Handler;
import android.os.Looper;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
String TAG = "Log: ";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(isReadStoragePermissionGranted()){
Intent myIntent = new Intent(this, FileSystemObserverService.class);
this.startService(myIntent);
}
}
public boolean isReadStoragePermissionGranted() {
if (Build.VERSION.SDK_INT >= 23) {
if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)
== PackageManager.PERMISSION_GRANTED) {
Log.v(TAG,"Permission is granted1");
return true;
} else {
Log.v(TAG,"Permission is revoked1");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 3);
return false;
}
}
else { //permission is automatically granted on sdk<23 upon installation
Log.v(TAG,"Permission is granted1");
return true;
}
}
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 3:
Log.d(TAG, "External storage1");
if(grantResults[0]== PackageManager.PERMISSION_GRANTED){
Log.v(TAG,"Permission: "+permissions[0]+ "was "+grantResults[0]);
}else{
}
break;
}
}
}
FileSystemOberveService
package com.spicysoftware.phonesaver;
import android.app.Service;
import android.content.Intent;
import android.os.Environment;
import android.os.FileObserver;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.util.Log;
import android.widget.Toast;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
public class FileSystemObserverService extends Service {
String externalPath = "";
String internalPath = "";
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
observe();
return super.onStartCommand(intent, flags, startId);
}
public File getInternalStoragePath() {
File parent = Environment.getExternalStorageDirectory().getParentFile();
File external = Environment.getExternalStorageDirectory();
File[] files = parent.listFiles();
File internal = null;
if (files != null) {
for (int i = 0; i < files.length; i++) {
if (files[i].getName().toLowerCase().startsWith("sdcard") && !files[i].equals(external)) {
internal = files[i];
}
}
}
return internal;
}
public File getExtenerStoragePath() {
return Environment.getExternalStorageDirectory();
}
public void observe() {
Thread t = new Thread(new Runnable() {
#Override
public void run() {
//File[] listOfFiles = new File(path).listFiles();
File str = getInternalStoragePath();
if (str != null) {
internalPath = str.getAbsolutePath();
new Obsever(internalPath).startWatching();
}
str = getExtenerStoragePath();
if (str != null) {
externalPath = str.getAbsolutePath();
new Obsever(externalPath).startWatching();
}
}
});
t.setPriority(Thread.MIN_PRIORITY);
t.start();
}
class Obsever extends FileObserver {
List<SingleFileObserver> mObservers;
String mPath;
int mMask;
public Obsever(String path) {
// TODO Auto-generated constructor stub
this(path, ALL_EVENTS);
}
public Obsever(String path, int mask) {
super(path, mask);
mPath = path;
mMask = mask;
// TODO Auto-generated constructor stub
}
#Override
public void startWatching() {
// TODO Auto-generated method stub
if (mObservers != null)
return;
mObservers = new ArrayList<SingleFileObserver>();
Stack<String> stack = new Stack<String>();
stack.push(mPath);
while (!stack.empty()) {
String parent = stack.pop();
mObservers.add(new SingleFileObserver(parent, mMask));
File path = new File(parent);
File[] files = path.listFiles();
if (files == null) continue;
for (int i = 0; i < files.length; ++i) {
if (files[i].isDirectory() && !files[i].getName().equals(".") && !files[i].getName().equals("..")) {
stack.push(files[i].getPath());
}
}
}
for (int i = 0; i < mObservers.size(); i++) {
mObservers.get(i).startWatching();
}
}
#Override
public void stopWatching() {
// TODO Auto-generated method stub
if (mObservers == null)
return;
for (int i = 0; i < mObservers.size(); ++i) {
mObservers.get(i).stopWatching();
}
mObservers.clear();
mObservers = null;
}
#Override
public void onEvent(int event, final String path) {
if (event == FileObserver.OPEN) {
Log.v("Event: ", "Open" + path);
// makeToast("Opened: "+path);
} else if (event == FileObserver.CREATE && (!path.equals(".probe"))) {
Log.v("Event: ", "Create" + path);
// makeToast("Created: "+path);
} else if (event == FileObserver.DELETE_SELF || event == FileObserver.DELETE) {
Log.v("Event: ", "Delete" + path);
// makeToast("Deleted: "+path);
} else if (event == FileObserver.MOVE_SELF || event == FileObserver.MOVED_FROM || event == FileObserver.MOVED_TO) {
Log.v("Event: ", "Move" + path);
// makeToast("Moved: "+path);
}
}
private class SingleFileObserver extends FileObserver {
private String mPath;
public SingleFileObserver(String path, int mask) {
super(path, mask);
// TODO Auto-generated constructor stub
mPath = path;
}
#Override
public void onEvent(int event, String path) {
// TODO Auto-generated method stub
String newPath = mPath + "/" + path;
Obsever.this.onEvent(event, newPath);
}
}
}
/*
public void makeToast(final String strMessage){
//Let this be the code in your n'th level thread from main UI thread
Handler h = new Handler(Looper.getMainLooper());
h.post(new Runnable() {
public void run() {
Toast.makeText(getApplicationContext(), strMessage, Toast.LENGTH_SHORT).show();
}
});
}
*/
}
StartupReceiver
package com.spicysoftware.phonesaver;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
public class StartupReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent myIntent = new Intent(context, FileSystemObserverService.class);
context.startService(myIntent);
}
}

Canvas drawing Blues

developing an application to take a photo and draw GPS coordinates over it.
just gave a test for the drawtext() method, which isn't showing up.
GPS is working fine.
Camera is working fine.
Canvas is having problems.
code for mainactivity.java
package com.example.camera;
import android.os.Bundle;
import android.app.Activity;
import android.widget.ImageView;
import android.widget.Button;
import android.view.View;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.net.Uri;
import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.provider.MediaStore;
import java.io.File;
import java.io.FileOutputStream;
import android.os.Environment;
import android.util.Log;
import java.text.SimpleDateFormat;
import java.util.Locale;
import java.util.Date;
import android.widget.Toast;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
public class MainActivity extends Activity
{
double lat,lon;
private static final String TAG = "CallCamera";
private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 0;
private String photoUri=null;
Uri fileUri = null;
ImageView photoImage = null;
private File getOutputPhotoFile()
{
File directory = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), getPackageName());
Log.d("directory check ", directory.toString());
if (!directory.exists())
{
if (!directory.mkdirs())
{
Log.e(TAG, "Failed to create storage directory.");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss", Locale.US).format(new Date());
return new File(directory.getPath() + File.separator + "IMG_"
+ timeStamp + ".jpg");
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
photoImage = (ImageView) findViewById(R.id.photo_image);
try
{
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
LocationListener ll = new mylocationlistener();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
}
catch(Exception e)
{
Log.d("GPS","Exception in location part-->"+e.toString());
}
Button callCameraButton = (Button)
findViewById(R.id.button_callcamera);
callCameraButton.setOnClickListener( new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = Uri.fromFile(getOutputPhotoFile());
i.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ );
}
}
);
}
private class mylocationlistener implements LocationListener
{
#Override
public void onLocationChanged(Location location)
{
if (location != null)
{
Log.d("LOCATION CHANGED", location.getLatitude() + "");
Log.d("LOCATION CHANGED", location.getLongitude() + "");
lat=location.getLatitude();
lon=location.getLongitude();
}
}
#Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String arg0)
{
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQ)
{
if (resultCode == RESULT_OK)
{
Uri photoUri = null;
if (data == null)
{
// A known bug here! The image should have saved in fileUri
Log.d("Image Code","Image Saved");
photoUri = fileUri;
}
else
{
photoUri = data.getData();
Log.d("Image Code","Image Saved at"+data.getData());
}
drawLatLong(photoUri.getPath());
}
else if (resultCode == RESULT_CANCELED)
{
Log.d("Image Code", "Cancled");
}
else
{
Log.d("Image Code", "Callout for image capture failed!");
}
}
}
/**
* takes the PhotoURI and draws the Latitude and longitude over it
* #param photoUri
*/
private void drawLatLong(String photoUri)
{
File imageFile = new File (photoUri);
if (imageFile.exists())
{
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
// Resources res=getResources();
// BitmapDrawable drawable = new BitmapDrawable(res,bitmap);
try
{
Canvas canvas = new Canvas(bitmap);
Paint paint = new Paint();
paint.setColor(Color.WHITE); // Text Color
paint.setStrokeWidth(12); // Text Size
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OVER)); // Text Overlapping Pattern
// some more settings...
canvas.drawBitmap(bitmap, 0, 0, paint);
canvas.drawText("Testing...", 10, 10, paint);
-
FileOutputStream fOut = new FileOutputStream(photoUri);
Log.d("Path"," "+photoUri);
bitmap.compress(Bitmap.CompressFormat.JPEG, 85, fOut);
fOut.flush();
fOut.close();
System.out.println(photoUri);
//bitmap.recycle();
// System.gc();
}
catch(Exception ex)
{
Log.d("Canvas Part", "Exception caused in canvas drawing-->"+ex.toString());
}
showPhoto(bitmap);
}
}
/**
* Takes the Bitmap from the drawLatLong() method and displays it over the image view.
* #param bitmapShow
*/
private void showPhoto(Bitmap bitmapShow)
{
try
{
Resources res=getResources();
BitmapDrawable drawable = new BitmapDrawable(res,bitmapShow);
photoImage.setImageDrawable(drawable);
photoImage.setScaleType(ImageView.ScaleType.FIT_CENTER);
photoImage.setImageBitmap(bitmapShow);
}
catch(Exception ex)
{
Log.d("canvas","exception in canvas"+ex);
}
}
}
the manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.camera"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-feature android:name="android.hardware.camera" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.camera.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

The bitmap needs to be inMutable. set it with the following code.
BitmapFactory.Options options = new BitmapFactory.Options();
options.inMutable = true;
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath(),options);
This section of the code is not needed as the canvas already has this bitmap.
//Not needed:
//canvas.drawBitmap(bitmap, 0, 0, paint);

unknown GoogleAuthException while getting the token

Similar questions are already available. But in my case I checked both SHA1 and my scope, they are correct and the account is also available. But still it returns unknown GoogleAuthException. My code is :-
MainActivity.java
package com.simon.learn.accountgetter;
import java.io.IOException;
import java.util.ArrayList;
import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.auth.GoogleAuthException;
import com.google.android.gms.auth.GoogleAuthUtil;
import com.google.android.gms.auth.UserRecoverableAuthException;
import com.google.android.gms.common.AccountPicker;
public class MainActivity extends Activity {
AccountManager am;
Account[] accounts;
ArrayList<String> accNames = new ArrayList<String>();
Button signin;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
am = AccountManager.get(getApplicationContext());
accounts = am.getAccountsByType("com.google");
// accounts=am.getAccounts();
signin = (Button) findViewById(R.id.signinBt);
signin.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = AccountPicker.newChooseAccountIntent(null,
null, new String[] { "com.google" }, false, null, null,
null, null);
startActivityForResult(intent, 13);
}
});
}
private void getToken(String accountName) {
new GetTokenTask(MainActivity.this, accountName,
"oauth2:https://www.googleapis.com/auth/userinfo.profile")
.execute();
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
String token = null;
if (requestCode == 13) {
if (resultCode == RESULT_OK) {
String accountName = data
.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
Log.e("simon", accountName);
Toast.makeText(getApplicationContext(), accountName,
Toast.LENGTH_LONG).show();
getToken(accountName);
// Toast.makeText(getApplicationContext(),
// "The token is : "+token, Toast.LENGTH_LONG).show();
}
}
}
public class GetTokenTask extends AsyncTask<Void, Void, String> {
Activity activity;
String scope;
String email;
public GetTokenTask(Activity activity, String email, String scope) {
this.activity = activity;
this.scope = scope;
this.email = email;
}
#Override
protected String doInBackground(Void... params) {
String token = null;
try {
Log.e("simon","Scope : "+scope+ " email "+ email);
token = GoogleAuthUtil.getToken(activity, email, scope);
} catch (UserRecoverableAuthException e) {
// TODO Auto-generated catch block
Log.e("simon","UserRecoverableAuthException");
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("simon","IOException");
e.printStackTrace();
} catch (GoogleAuthException e) {
// TODO Auto-generated catch block
Log.e("simon","GoogleAuthException : "+e.getMessage());
e.printStackTrace();
}
return token;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
Log.e("simon", "The Token is : " + result);
Toast.makeText(getApplicationContext(), "The Token is : " + result,
Toast.LENGTH_LONG).show();
super.onPostExecute(result);
}
}
}
It is showing unknown GoogleAuthException. See my manifest file also
Manifest.java
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.simon.learn.accountgetter"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Please help me. Thanks in advance

How to connect a mobile and a printer via bluetooth in android?

Can anyone tell me how to connect a mobile and a printer via bluetooth to print a text file in android?
That is,if i click the print button from the android application,the printer has to print that corresponding file.As per my knowledge i have searched for it in Google, but i couldn't find any good samples to do it.Has anyone have at-least one sample android program to do this, it will be better to clear my chaos.
Suggestions please.
Thanks for your precious time!..

Bluetooth Printer Android Example
Create a new android project BlueToothPrinterApp in your editor.
Step 1:
Create main activity like below
com.example.BlueToothPrinterApp / BlueToothPrinterApp.java
package com.example.BlueToothPrinterApp;
import android.app.Activity;
import android.os.Bundle;
import java.io.IOException;
import java.io.OutputStream;
import android.bluetooth.BluetoothSocket;
import android.content.ContentValues;
import android.content.Intent;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class BlueToothPrinterApp extends Activity {
/** Called when the activity is first created. */
EditText message;
Button printbtn;
byte FONT_TYPE;
private static BluetoothSocket btsocket;
private static OutputStream btoutputstream;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
message = (EditText) findViewById(R.id.message);
printbtn = (Button) findViewById(R.id.printButton);
printbtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
connect();
}
});
}
protected void connect() {
if (btsocket == null) {
Intent BTIntent = new Intent(getApplicationContext(), BTDeviceList.class);
this.startActivityForResult(BTIntent, BTDeviceList.REQUEST_CONNECT_BT);
} else {
OutputStream opstream = null;
try {
opstream = btsocket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
btoutputstream = opstream;
print_bt();
}
}
private void print_bt() {
try {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
btoutputstream = btsocket.getOutputStream();
byte[] printformat = {
0x1B,
0× 21,
FONT_TYPE
};
btoutputstream.write(printformat);
String msg = message.getText().toString();
btoutputstream.write(msg.getBytes());
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.write(0x0D);
btoutputstream.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onDestroy() {
super.onDestroy();
try {
if (btsocket != null) {
btoutputstream.close();
btsocket.close();
btsocket = null;
}
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
try {
btsocket = BTDeviceList.getSocket();
if (btsocket != null) {
print_bt();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
Step 2:
com.example.BlueToothPrinterApp / BTDeviceList.java
package com.example.BlueToothPrinterApp;
import java.io.IOException;
import java.util.Set;
import java.util.UUID;
import android.app.ListActivity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class BTDeviceList extends ListActivity {
static public final int REQUEST_CONNECT_BT = 0× 2300;
static private final int REQUEST_ENABLE_BT = 0× 1000;
static private BluetoothAdapter mBluetoothAdapter = null;
static private ArrayAdapter < String > mArrayAdapter = null;
static private ArrayAdapter < BluetoothDevice > btDevices = null;
private static final UUID SPP_UUID = UUID
.fromString(“8 ce255c0 - 200 a - 11e0 - ac64 - 0800200 c9a66″);
// UUID.fromString(“00001101-0000-1000-8000-00805F9B34FB”);
static private BluetoothSocket mbtSocket = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle(“Bluetooth Devices”);
try {
if (initDevicesList() != 0) {
this.finish();
return;
}
} catch (Exception ex) {
this.finish();
return;
}
IntentFilter btIntentFilter = new IntentFilter(
BluetoothDevice.ACTION_FOUND);
registerReceiver(mBTReceiver, btIntentFilter);
}
public static BluetoothSocket getSocket() {
return mbtSocket;
}
private void flushData() {
try {
if (mbtSocket != null) {
mbtSocket.close();
mbtSocket = null;
}
if (mBluetoothAdapter != null) {
mBluetoothAdapter.cancelDiscovery();
}
if (btDevices != null) {
btDevices.clear();
btDevices = null;
}
if (mArrayAdapter != null) {
mArrayAdapter.clear();
mArrayAdapter.notifyDataSetChanged();
mArrayAdapter.notifyDataSetInvalidated();
mArrayAdapter = null;
}
finalize();
} catch (Exception ex) {} catch (Throwable e) {}
}
private int initDevicesList() {
flushData();
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(getApplicationContext(), “Bluetooth not supported!!”, Toast.LENGTH_LONG).show();
return -1;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
mArrayAdapter = new ArrayAdapter < String > (getApplicationContext(),
android.R.layout.simple_list_item_1);
setListAdapter(mArrayAdapter);
Intent enableBtIntent = new Intent(
BluetoothAdapter.ACTION_REQUEST_ENABLE);
try {
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} catch (Exception ex) {
return -2;
}
Toast.makeText(getApplicationContext(), “Getting all available Bluetooth Devices”, Toast.LENGTH_SHORT)
.show();
return 0;
}
#Override
protected void onActivityResult(int reqCode, int resultCode, Intent intent) {
super.onActivityResult(reqCode, resultCode, intent);
switch (reqCode) {
case REQUEST_ENABLE_BT:
if (resultCode == RESULT_OK) {
Set < BluetoothDevice > btDeviceList = mBluetoothAdapter
.getBondedDevices();
try {
if (btDeviceList.size() > 0) {
for (BluetoothDevice device: btDeviceList) {
if (btDeviceList.contains(device) == false) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress());
mArrayAdapter.notifyDataSetInvalidated();
}
}
}
} catch (Exception ex) {}
}
break;
}
mBluetoothAdapter.startDiscovery();
}
private final BroadcastReceiver mBTReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
try {
if (btDevices == null) {
btDevices = new ArrayAdapter < BluetoothDevice > (
getApplicationContext(), android.R.id.text1);
}
if (btDevices.getPosition(device) < 0) {
btDevices.add(device);
mArrayAdapter.add(device.getName() + “\n” +
device.getAddress() + “\n”);
mArrayAdapter.notifyDataSetInvalidated();
}
} catch (Exception ex) {
// ex.fillInStackTrace();
}
}
}
};
#Override
protected void onListItemClick(ListView l, View v, final int position,
long id) {
super.onListItemClick(l, v, position, id);
if (mBluetoothAdapter == null) {
return;
}
if (mBluetoothAdapter.isDiscovering()) {
mBluetoothAdapter.cancelDiscovery();
}
Toast.makeText(
getApplicationContext(), “Connecting to” + btDevices.getItem(position).getName() + “, ”
+btDevices.getItem(position).getAddress(),
Toast.LENGTH_SHORT).show();
Thread connectThread = new Thread(new Runnable() {
#Override
public void run() {
try {
boolean gotuuid = btDevices.getItem(position)
.fetchUuidsWithSdp();
UUID uuid = btDevices.getItem(position).getUuids()[0]
.getUuid();
mbtSocket = btDevices.getItem(position)
.createRfcommSocketToServiceRecord(uuid);
mbtSocket.connect();
} catch (IOException ex) {
runOnUiThread(socketErrorRunnable);
try {
mbtSocket.close();
} catch (IOException e) {
// e.printStackTrace();
}
mbtSocket = null;
return;
} finally {
runOnUiThread(new Runnable() {
#Override
public void run() {
finish();
}
});
}
}
});
connectThread.start();
}
private Runnable socketErrorRunnable = new Runnable() {
#Override
public void run() {
Toast.makeText(getApplicationContext(), “Cannot establish connection”, Toast.LENGTH_SHORT).show();
mBluetoothAdapter.startDiscovery();
}
};
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, Menu.FIRST, Menu.NONE, “Refresh Scanning”);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case Menu.FIRST:
initDevicesList();
break;
}
return true;
}
}
Step 3:
Edit your main.xml file and paste below code.
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp">
<TextView
android:id="#+id/msgtextlbl"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Enter Your Message : "/>
<EditText
android:id="#+id/message"
android:layout_width="fill_parent"
android:layout_height="100dp"
android:layout_below="#+id/msgtextlbl"
android:text=""/>
<Button
android:id="#+id/printButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/message"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dip"
android:text="Print"/>
</RelativeLayout>
Step 4:
Now edit your AndroidManifest.xml
Add bluetooth permission and admin permission.
AndroidManifest.xml
<?xml version=”1.0″ encoding=”utf-8″?>
<manifest
xmlns:android=”http://schemas.android.com/apk/res/android
package=”com.example.BlueToothPrinterApp”
android:versionCode=”1″
android:versionName=”1.0″>
<uses-sdk android:minSdkVersion=”14″ />
<uses-permission android:name=”android.permission.BLUETOOTH”></uses-permission>
<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”></uses-permission>
<application
android:label=”#string/app_name”
android:icon=”#drawable/ic_launcher”>
<activity
android:name=”BlueToothPrinterApp”
android:label=”#string/app_name”>
<intent-filter>
<action android:name=”android.intent.action.MAIN” />
<category android:name=”android.intent.category.LAUNCHER” />
</intent-filter>
</activity>
<activity android:name=”BTDeviceList”></activity>
</application>
</manifest>
Compile and run this application. Enter message and press print button.
You will see list of bluetooth devices. Select bluettoth printer.
Check print on your bluetooth printer.
here is the CODE Reference...

You can use this awesome lib, you can connect to any printer and print easily,
https://github.com/mazenrashed/Printooth
you can download it by:
implementation 'com.github.mazenrashed:Printooth:${LAST_VERSION}'
and use it like:
var printables = ArrayList<Printable>()
var printable = Printable.PrintableBuilder()
.setText("Hello World")
printables.add(printable)
BluetoothPrinter.printer().print(printables)

Transfer Data between Android devices using wifi direct?

I have recently implement wifi direct into my project,my aim is pass string value between two wifidirect connected devices when some of my app condition satisfies.right now i have listed all peers and also made connection between the selected peer.what my idea is to pass a json file between the devices.so before try to execute that idea i try to pass a image file between two devices.i followed the steps from the android wifidirect tutorial.listing peers and the connection between the peers is success full but i cant pass the data between the devices.the follwing is my code.
FileTransferService.java
package jing.app.directwifi;
import android.app.IntentService;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.util.Log;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
/**
* A service that process each file transfer request i.e Intent by opening a
* socket connection with the WiFi Direct Group Owner and writing the file
*/
public class FileTransferService extends IntentService {
private static final int SOCKET_TIMEOUT = 5000;
public static final String ACTION_SEND_FILE = "jing.app.directwifi.SEND_FILE";
public static final String EXTRAS_FILE_PATH = "file_url";
public static final String EXTRAS_GROUP_OWNER_ADDRESS = "go_host";
public static final String EXTRAS_GROUP_OWNER_PORT = "go_port";
public FileTransferService(String name) {
super(name);
}
public FileTransferService() {
super("FileTransferService");
}
/*
* (non-Javadoc)
* #see android.app.IntentService#onHandleIntent(android.content.Intent)
*/
#Override
protected void onHandleIntent(Intent intent) {
Context context = getApplicationContext();
if (intent.getAction().equals(ACTION_SEND_FILE)) {
String fileUri = intent.getExtras().getString(EXTRAS_FILE_PATH);
String host = intent.getExtras().getString(EXTRAS_GROUP_OWNER_ADDRESS);
Socket socket = new Socket();
int port = intent.getExtras().getInt(EXTRAS_GROUP_OWNER_PORT);
try {
// Log.d(WiFiDirectActivity.TAG, "Opening client socket - ");
socket.bind(null);
socket.connect((new InetSocketAddress(host, port)), SOCKET_TIMEOUT);
Log.d("connected", "Client socket - " + socket.isConnected());
OutputStream stream = socket.getOutputStream();
ContentResolver cr = context.getContentResolver();
InputStream is = null;
try {
is = cr.openInputStream(Uri.parse(fileUri));
} catch (FileNotFoundException e) {
Log.d("exp", e.toString());
}
MainActivity.copyFile(is, stream);
Log.d("exp" ,"Client: Data written");
} catch (IOException e) {
Log.e("exp", e.getMessage());
} finally {
if (socket != null) {
if (socket.isConnected()) {
try {
socket.close();
} catch (IOException e) {
// Give up
e.printStackTrace();
}
}
}
}
}
}
}
Main Activity.java
package jing.app.directwifi;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Collection;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.Uri;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pConfig;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.net.wifi.p2p.WifiP2pManager.ActionListener;
import android.net.wifi.p2p.WifiP2pManager.Channel;
import android.net.wifi.p2p.WifiP2pManager.ConnectionInfoListener;
import android.net.wifi.p2p.WifiP2pManager.PeerListListener;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.provider.Settings;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener, android.content.DialogInterface.OnClickListener, ConnectionInfoListener {
private WifiP2pManager mManager;
private Channel mChannel;
private BroadcastReceiver mReceiver;
private IntentFilter mIntentFilter;
private Button mDiscover;
private TextView mDevices;
public ArrayAdapter mAdapter;
private ArrayList<WifiP2pDevice> mDeviceList = new ArrayList<WifiP2pDevice>();
protected static final int CHOOSE_FILE_RESULT_CODE = 20;
int flag=0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDiscover = (Button) findViewById(R.id.discover);
mDiscover.setOnClickListener(this);
mDevices = (TextView) findViewById(R.id.peers);
mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mManager.initialize(this, getMainLooper(), null);
mReceiver = new WiFiDirectReceiver(mManager, mChannel, this);
mIntentFilter = new IntentFilter();
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
}
#Override
protected void onResume() {
super.onResume();
registerReceiver(mReceiver, mIntentFilter);
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(mReceiver);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
private class WiFiDirectReceiver extends BroadcastReceiver {
private WifiP2pManager mManager;
private Channel mChannel;
private MainActivity mActivity;
public WiFiDirectReceiver(WifiP2pManager manager, Channel channel, MainActivity activity) {
super();
mManager = manager;
mChannel = channel;
mActivity = activity;
}
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
String title = "ANDROID_ID[" + getAndroid_ID() + "]";
title += " MAC[" + getMACAddress() + "]";
Toast.makeText(mActivity, "Wi-Fi Direct is enabled."+title, Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(mActivity, "Wi-Fi Direct is disabled.", Toast.LENGTH_SHORT).show();
}
} else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
if (mManager != null) {
mManager.requestPeers(mChannel, new PeerListListener() {
#Override
public void onPeersAvailable(WifiP2pDeviceList peers) {
if (peers != null) {
mDeviceList.addAll(peers.getDeviceList());
ArrayList<String> deviceNames = new ArrayList<String>();
for (WifiP2pDevice device : mDeviceList) {
deviceNames.add(device.deviceName);
}
if (deviceNames.size() > 0) {
mAdapter = new ArrayAdapter<String>(mActivity, android.R.layout.simple_list_item_1, deviceNames);
if(flag==0)
{
flag=1;
showDeviceListDialog();
}
} else {
Toast.makeText(mActivity, "Device list is empty.", Toast.LENGTH_SHORT).show();
}
}
}
});
}
} else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
} else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
}
}
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.discover:
onDiscover();
break;
}
}
private void onDiscover() {
mManager.discoverPeers(mChannel, new ActionListener() {
#Override
public void onSuccess() {
Toast.makeText(MainActivity.this, "Discover peers successfully.", Toast.LENGTH_SHORT).show();
}
#Override
public void onFailure(int reason) {
Toast.makeText(MainActivity.this, "Discover peers failed.", Toast.LENGTH_SHORT).show();
}
});
}
private void showDeviceListDialog() {
DeviceListDialog deviceListDialog = new DeviceListDialog();
deviceListDialog.show(getFragmentManager(), "devices");
}
private class DeviceListDialog extends DialogFragment {
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle("Select a device")
.setSingleChoiceItems(mAdapter, 0, MainActivity.this)
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
return builder.create();
}
}
#Override
public void onClick(DialogInterface dialog, int which) {
onDeviceSelected(which);
dialog.dismiss();
}
private void onDeviceSelected(int which) {
WifiP2pDevice device = mDeviceList.get(which);
if (device == null) {
return;
}
WifiP2pConfig config = new WifiP2pConfig();
config.deviceAddress = device.deviceAddress;
mManager.connect(mChannel, config, new ActionListener() {
#Override
public void onSuccess() {
Toast.makeText(MainActivity.this, "Connected", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, CHOOSE_FILE_RESULT_CODE);
}
#Override
public void onFailure(int reason) {
Toast.makeText(MainActivity.this, "Failed to connect", Toast.LENGTH_SHORT).show();
}
});
}
/**
* ANDROID_ID
*/
private String getAndroid_ID() {
return Settings.Secure.getString(getContentResolver(), Settings.Secure.ANDROID_ID);
}
/**
* Wi-Fi MAC
*/
private String getMACAddress() {
WifiManager manager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = manager.getConnectionInfo();
String mac = wifiInfo.getMacAddress();
// After the group negotiation, we assign the group owner as the file
// server. The file server is single threaded, single connection server
// socket.
new FileServerAsyncTask(getApplicationContext())
.execute();
return mac;
}
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
// User has picked an image. Transfer it to group owner i.e peer using
// FileTransferService.
Uri uri = data.getData();
Log.d("intent", "Intent----------- " + uri);
Intent serviceIntent = new Intent(MainActivity.this, FileTransferService.class);
serviceIntent.setAction(FileTransferService.ACTION_SEND_FILE);
serviceIntent.putExtra(FileTransferService.EXTRAS_FILE_PATH, uri.toString());
serviceIntent.putExtra(FileTransferService.EXTRAS_GROUP_OWNER_ADDRESS,
getMACAddress());
serviceIntent.putExtra(FileTransferService.EXTRAS_GROUP_OWNER_PORT, 8988);
startService(serviceIntent);
}
/**
* A simple server socket that accepts connection and writes some data on
* the stream.
*/
public static class FileServerAsyncTask extends AsyncTask<Void, Void, String> {
private Context context;
/**
* #param context
* #param statusText
*/
public FileServerAsyncTask(Context context) {
this.context = context;
}
#Override
protected String doInBackground(Void... params) {
try {
System.out.println("insideeeeeeeeeeeeeeeeeeeeeeee");
ServerSocket serverSocket = new ServerSocket(8988);
Log.d("Server: Socket opened", "Server: Socket opened");
Socket client = serverSocket.accept();
Log.d("Server: connection done", "Server: connection done");
final File f = new File(Environment.getExternalStorageDirectory() + "/"
+ context.getPackageName() + "/wifip2pshared-" + System.currentTimeMillis()
+ ".jpg");
File dirs = new File(f.getParent());
if (!dirs.exists())
dirs.mkdirs();
f.createNewFile();
Log.d("server: copying files ", "server: copying files " + f.toString());
InputStream inputstream = client.getInputStream();
copyFile(inputstream, new FileOutputStream(f));
serverSocket.close();
return f.getAbsolutePath();
} catch (IOException e) {
Log.e("exp", e.getMessage());
System.out.println(":iooo:"+e);
return null;
}
}
/*
* (non-Javadoc)
* #see android.os.AsyncTask#onPostExecute(java.lang.Object)
*/
#Override
protected void onPostExecute(String result) {
if (result != null) {
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse("file://" + result), "image/*");
context.startActivity(intent);
}
}
/*
* (non-Javadoc)
* #see android.os.AsyncTask#onPreExecute()
*/
#Override
protected void onPreExecute() {
}
}
public static boolean copyFile(InputStream inputStream, OutputStream out) {
byte buf[] = new byte[1024];
int len;
long startTime=System.currentTimeMillis();
try {
while ((len = inputStream.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();
inputStream.close();
long endTime=System.currentTimeMillis()-startTime;
Log.v("","Time taken to transfer all bytes is : "+endTime);
} catch (IOException e) {
Log.d("exp", e.toString());
return false;
}
return true;
}
#Override
public void onConnectionInfoAvailable(WifiP2pInfo info) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), "connectioninfoo", 3000).show();
}
}
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="jing.app.directwifi"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="16" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- Market filtering -->
<uses-feature
android:name="android.hardware.wifi.direct"
android:required="true" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="jing.app.directwifi.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Used for transferring files after a successful connection -->
<service
android:name=".FileTransferService"
android:enabled="true" />
</application>
</manifest>
These are files used in my code .form the tutorial i have found that
new FileServerAsyncTask(getApplicationContext())
.execute();
where the the incomming data is begin accepted so when i need to execute this asyn thread,so anyone help me in which portion i have made the mistake.how can i transfer the file between devices .

The android code from the demo wifi direct project is able to pass file is unidirectional. ie. you can send file from client to server only. You need furthur modifications to make it work in both direction.
EDIT 2:
For that you need to know the IP address of both connected peers. Use the following function which I made following various sources with my modifications wherever appropriate.
public static String getIpAddress() {
try {
List<NetworkInterface> interfaces = Collections
.list(NetworkInterface.getNetworkInterfaces());
/*
* for (NetworkInterface networkInterface : interfaces) { Log.v(TAG,
* "interface name " + networkInterface.getName() + "mac = " +
* getMACAddress(networkInterface.getName())); }
*/
for (NetworkInterface intf : interfaces) {
if (!getMACAddress(intf.getName()).equalsIgnoreCase(
Globals.thisDeviceAddress)) {
// Log.v(TAG, "ignore the interface " + intf.getName());
// continue;
}
if (!intf.getName().contains("p2p"))
continue;
Log.v(TAG,
intf.getName() + " " + getMACAddress(intf.getName()));
List<InetAddress> addrs = Collections.list(intf
.getInetAddresses());
for (InetAddress addr : addrs) {
// Log.v(TAG, "inside");
if (!addr.isLoopbackAddress()) {
// Log.v(TAG, "isnt loopback");
String sAddr = addr.getHostAddress().toUpperCase();
Log.v(TAG, "ip=" + sAddr);
boolean isIPv4 = InetAddressUtils.isIPv4Address(sAddr);
if (isIPv4) {
if (sAddr.contains("192.168.49.")) {
Log.v(TAG, "ip = " + sAddr);
return sAddr;
}
}
}
}
}
} catch (Exception ex) {
Log.v(TAG, "error in parsing");
} // for now eat exceptions
Log.v(TAG, "returning empty ip address");
return "";
}
public static String getMACAddress(String interfaceName) {
try {
List<NetworkInterface> interfaces = Collections
.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface intf : interfaces) {
if (interfaceName != null) {
if (!intf.getName().equalsIgnoreCase(interfaceName))
continue;
}
byte[] mac = intf.getHardwareAddress();
if (mac == null)
return "";
StringBuilder buf = new StringBuilder();
for (int idx = 0; idx < mac.length; idx++)
buf.append(String.format("%02X:", mac[idx]));
if (buf.length() > 0)
buf.deleteCharAt(buf.length() - 1);
return buf.toString();
}
} catch (Exception ex) {
} // for now eat exceptions
return "";
/*
* try { // this is so Linux hack return
* loadFileAsString("/sys/class/net/" +interfaceName +
* "/address").toUpperCase().trim(); } catch (IOException ex) { return
* null; }
*/
}

I think the way you initialize client makes the problem.
You need to call this
new FileServerAsyncTask(getApplicationContext()).execute();
after the connection is established and check if it's a client.
Now you are creating a client socket only if it is a server(group owner) and always when you call to get a MAC address.
So on the client side you are not intializing the socket and so not able to receive the file.
Once check the WifiDirect sample demo provided in the SDK, you may get more idea.