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Why do I get ClassCastException when I extend a class?

I'm developing an app which can read data from a Bluetooth RFID Reader, but everytime i start the BluetoothActivity (it's a tabbed activity), it always shows a ClassCastException, below is my code..
BluetoothActivity class:
package com.siscaproject.sisca.Activity;
import android.net.Uri;
import android.support.annotation.Nullable;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.siscaproject.sisca.Fragment.RegisterFragment;
import com.siscaproject.sisca.Fragment.SearchFragment;
import com.siscaproject.sisca.R;
import com.siscaproject.sisca.Utilities.FamsModel;
import com.siscaproject.sisca.Utilities.TSLBluetoothDeviceActivity;
import com.siscaproject.sisca.Utilities.TSLBluetoothDeviceApplication;
import com.uk.tsl.rfid.asciiprotocol.AsciiCommander;
import com.uk.tsl.rfid.asciiprotocol.responders.LoggerResponder;
import java.util.ArrayList;
import butterknife.BindView;
import butterknife.ButterKnife;
public class BluetoothActivity extends TSLBluetoothDeviceActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
#BindView(R.id.viewpager_bluetooth) ViewPager mViewPager;
#BindView(R.id.toolbar_bluetooth) Toolbar mToolbar;
#BindView(R.id.tab_bluetooth) TabLayout mTabLayout;
private FamsModel mModel;
public AsciiCommander getCommander(){
return ((TSLBluetoothDeviceApplication) getApplication()).getCommander();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bluetooth);
ButterKnife.bind(this);
setSupportActionBar(mToolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
setupViewPager(mViewPager);
mTabLayout.setupWithViewPager(mViewPager);
AsciiCommander commander = getCommander();
// Add the LoggerResponder - this simply echoes all lines received from the reader to the log
// and passes the line onto the next responder
// This is added first so that no other responder can consume received lines before they are logged.
commander.addResponder(new LoggerResponder());
// Add a synchronous responder to handle synchronous commands
commander.addSynchronousResponder();
}
private void setupViewPager(ViewPager viewPager){
SectionsPagerAdapter adapter = new SectionsPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new RegisterFragment(), "REGISTER");
adapter.addFragment(new SearchFragment(), "SEARCH");
viewPager.setAdapter(adapter);
}
#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_bluetooth, 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.menu_item_reconnect_reader) {
return true;
}
return super.onOptionsItemSelected(item);
}
public static class PlaceholderFragment extends Fragment {
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_bluetooth, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private ArrayList<Fragment> fragmentList = new ArrayList<>();
private ArrayList<String> fragmentTitleList = new ArrayList<>();
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
#Override
public int getCount() {
// Show 3 total pages.
return fragmentList.size();
}
public void addFragment(Fragment fragment, String title ){
fragmentList.add(fragment);
fragmentTitleList.add(title);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return fragmentTitleList.get(position);
}
}
}
TSLBluetoothDeviceActivity class:
package com.siscaproject.sisca.Utilities;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;
import com.siscaproject.sisca.BuildConfig;
import com.uk.tsl.rfid.DeviceListActivity;
import com.uk.tsl.rfid.asciiprotocol.AsciiCommander;
import java.util.Timer;
import java.util.TimerTask;
public class TSLBluetoothDeviceActivity extends AppCompatActivity {
// Debugging
private static final String TAG = "TSLBTDeviceActivity";
private static final boolean D = BuildConfig.DEBUG;
// Intent request codes
private static final int REQUEST_CONNECT_DEVICE_SECURE = 1;
private static final int REQUEST_CONNECT_DEVICE_INSECURE = 2;
private static final int REQUEST_ENABLE_BT = 3;
// Local Bluetooth adapter
private BluetoothAdapter mBluetoothAdapter = null;
private BluetoothDevice mDevice = null;
protected AsciiCommander getCommander() {
return ((TSLBluetoothDeviceApplication) getApplication()).getCommander();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get local Bluetooth adapter
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// Create the AsciiCommander to talk to the reader (if it doesn't already exist)
if (getCommander() == null) {
try {
TSLBluetoothDeviceApplication app = (TSLBluetoothDeviceApplication) getApplication();
AsciiCommander commander = new AsciiCommander(getApplicationContext());
app.setCommander(commander);
} catch (Exception e) {
fatalError("Unable to create AsciiCommander!");
}
}
}
// Terminate the app with the given message
private void fatalError(String message) {
Toast.makeText(this, message, Toast.LENGTH_LONG).show();
Timer t = new Timer();
t.schedule(new TimerTask() {
public void run() {
finish();
}
}, 1800);
}
protected void bluetoothNotAvailableError(String message) {
fatalError(message);
}
#Override
public void onStart() {
super.onStart();
// If no other attempt to connect is ongoing try to connect to last used reader
// Note: When returning from the Device List activity
if (mBluetoothAdapter.isEnabled()) {
if (mDevice == null) {
// Attempt to reconnect to the last reader used
Toast.makeText(this, "Reconnecting to last used reader...", Toast.LENGTH_SHORT).show();
getCommander().connect(null);
}
} else {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
#Override
public void onStop() {
super.onStop();
getCommander().disconnect();
mDevice = null;
}
protected void connectToDevice(Intent deviceData, boolean secure) {
Toast.makeText(this.getApplicationContext(), "Connecting...", Toast.LENGTH_LONG).show();
// Get the device MAC address
String address = deviceData.getExtras()
.getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
// Get the BluetoothDevice object
mDevice = mBluetoothAdapter.getRemoteDevice(address);
// Attempt to connect to the device
if (mDevice != null) {
getCommander().connect(mDevice);
} else {
if (D) Log.e(TAG, "Unable to obtain BluetoothDevice!");
}
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (D)
Log.d(TAG, "selectDevice() onActivityResult: " + resultCode + " for request: " + requestCode);
switch (requestCode) {
case REQUEST_CONNECT_DEVICE_SECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectToDevice(data, true);
}
break;
case REQUEST_CONNECT_DEVICE_INSECURE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
connectToDevice(data, false);
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode != Activity.RESULT_OK) {
// User did not enable Bluetooth or an error occurred
Log.d(TAG, "BT not enabled");
bluetoothNotAvailableError("Bluetooth was not enabled\nApplication Quitting...");
}
}
}
public void selectDevice() {
// Launch the DeviceListActivity to see devices and do scan
Intent serverIntent = new Intent(this, DeviceListActivity.class);
startActivityForResult(serverIntent, REQUEST_CONNECT_DEVICE_INSECURE);
}
public void disconnectDevice() {
mDevice = null;
getCommander().disconnect();
}
public void reconnectDevice() {
getCommander().connect(null);
}
}
The error log:
11-21 14:47:54.836 18956-18956/com.siscaproject.sisca E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.siscaproject.sisca, PID: 18956
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.siscaproject.sisca/com.siscaproject.sisca.Activity.BluetoothActivity}: java.lang.ClassCastException: android.app.Application cannot be cast to com.siscaproject.sisca.Utilities.TSLBluetoothDeviceApplication
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2318)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to com.siscaproject.sisca.Utilities.TSLBluetoothDeviceApplication
at com.siscaproject.sisca.Activity.BluetoothActivity.getCommander(BluetoothActivity.java:51)
at com.siscaproject.sisca.Utilities.TSLBluetoothDeviceActivity.onCreate(TSLBluetoothDeviceActivity.java:45)
at com.siscaproject.sisca.Activity.BluetoothActivity.onCreate(BluetoothActivity.java:57)
at android.app.Activity.performCreate(Activity.java:5411)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396) 
at android.app.ActivityThread.access$800(ActivityThread.java:139) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:149) 
at android.app.ActivityThread.main(ActivityThread.java:5257) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:515) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609) 
at dalvik.system.NativeStart.main(Native Method) 
I've followed this code from an app that works fine, but when I implemented it in my project it always shows this error, I'm not sure what I'm doing wrong.
---EDIT---
TSLBluetoothDeviceApplication class:
package com.siscaproject.sisca.Utilities;
import android.app.Application;
import com.uk.tsl.rfid.asciiprotocol.AsciiCommander;
public class TSLBluetoothDeviceApplication extends Application {
private static AsciiCommander commander = null;
/// Returns the current AsciiCommander
public AsciiCommander getCommander() {
return commander;
}
/// Sets the current AsciiCommander
public void setCommander(AsciiCommander _commander) {
commander = _commander;
}
}
Android Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.siscaproject.sisca">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<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"
tools:replace="android:icon">
<activity
android:name=".Activity.LoginActivity"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Activity.BluetoothTestActivity"
android:theme="#style/StandardTheme" />
<activity
android:name=".Activity.HomeActivity"
android:label="#string/title_activity_home"
android:theme="#style/AppTheme" />
<meta-data
android:name="com.google.android.gms.vision.DEPENDENCIES"
android:value="barcode" />
<activity android:name=".Activity.QRActivity" />
<activity
android:name=".Activity.BluetoothActivity"
android:label="#string/title_activity_bluetooth"
android:theme="#style/AppTheme"></activity>
</application>
</manifest>

getApplication() inside an activity returns an object of type Application. In your case you are trying to cast this object into TSLBluetoothDeviceApplication which, as defined by you, is an Activity type class.
As I see, you are trying to call getCommander() which is defined already in your TSL activity class. I assume you want getCommander() method from another class.. Make sure which one is.
public AsciiCommander getCommander(){
return ((TSLBluetoothDeviceApplication) getApplication()).getCommander();
}
This method is already inside TSLBluetoothDeviceApplication class.. I don't know what are you trying to achieve by trying to call same method which is already in your current class.
EDIT:
After the edited post, we noticed that the class was properly implemented, just forgot to add
android:name="com.path.to.ApplicationClass" into the Manifestfile under <application/> tag.
I will let the above answer also, because it may help others
Happy coding <3

It's clear that your application class is not used. You need to add it to your xml Application tag like this:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:name="com.siscaproject.sisca.Utilities. TSLBluetoothDeviceApplication"
android:theme="#style/AppTheme"
tools:replace="android:icon">
and the only change is adding android:name="com.siscaproject.sisca.Utilities. TSLBluetoothDeviceApplication" to the Application tag as your customized class.

avoid of send null from destroyed activity to restarted service

I want to programing app for data track in background , so I use service .
I want to write a program that monitors all data sent and received by the device, and when the total volume of received or received messages reaches a specified value, the Internet device is turned off.
So I used the following code to monitor the data:
 
mStartRX = TrafficStats.getTotalRxBytes ();
mStartTX = TrafficStats.getTotalTxBytes ();
And I used the services to work on the background in the background.
To specify the download or upload limit from the user with edittext, I requested this limit in mainactivity and send this value to the service.
The problem is when: When I destroy the program, I will restart the service and get the NULL value and the program crashes.
My application code:
Main Activity :
package ir.alexandre9009.service;
import android.app.AlertDialog;
import android.content.Context;
import android.net.TrafficStats;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
public static Handler mHandler = new Handler();
public static long UPP;
public static long DLL;
Button startService,stopService;
public Context context=this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (FirstService.mStartRX == TrafficStats.UNSUPPORTED || FirstService.mStartTX == TrafficStats.UNSUPPORTED) {
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.setTitle("Uh Oh!");
alert.setMessage("Your device does not support traffic stat monitoring.");
alert.show();
} else {
mHandler.postDelayed(mRunnable, 1000);
}
startService=(Button)findViewById(R.id.startService);
stopService=(Button)findViewById(R.id.stopService);
startService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText UP = (EditText) findViewById(R.id.UP);
String UPPP = UP.getText().toString();
UPP=Long.parseLong(UPPP);
EditText DL = (EditText) findViewById(R.id.DL);
String DLLL = DL.getText().toString();
DLL=Long.parseLong(DLLL);
Intent intent = new Intent(getApplicationContext(), FirstService.class);
String myString = DLLL;
intent.putExtra("StringName", myString);
startService(intent);
}
});
stopService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
stopService(new Intent(getBaseContext(),FirstService.class));
}
});
}
public final Runnable mRunnable = new Runnable() {
public void run() {
TextView RX = (TextView)findViewById(R.id.RX);
TextView TX = (TextView)findViewById(R.id.TX);
RX.setText(Long.toString(FirstService.rxBytes));
TX.setText(Long.toString(FirstService.txBytes));
mHandler.postDelayed(mRunnable, 1000);
}
};
}
Service :
package ir.alexandre9009.service;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.net.TrafficStats;
import android.net.wifi.WifiManager;
import android.os.Handler;
import android.os.IBinder;
import android.widget.TextView;
import android.widget.Toast;
public class FirstService extends Service{
public static long mStartRX ;
public static long mStartTX ;
public static long rxBytes ;
public static long txBytes ;
public long dl=MainActivity.DLL;
Context context=this;
private final Runnable mRunnable = new Runnable() {
public void run() {
rxBytes = (TrafficStats.getTotalRxBytes()- mStartRX)/1048576;
txBytes = (TrafficStats.getTotalTxBytes()- mStartTX)/1048576;
if (rxBytes==2) {
stopService(new Intent(getBaseContext(),FirstService.class));
Intent i = new Intent(context,MainActivity.class);
context.startActivity(i);
// WifiManager wifiManager = (WifiManager)getApplicationContext().getSystemService(Context.WIFI_SERVICE);
// wifiManager.setWifiEnabled(false);
//معرفی توست برای نمایش یک پیام کوتاه به کاربر در هنگام خاموش کردن وای فای
Toast.makeText(FirstService.this, "هشدار", Toast.LENGTH_LONG).show();
}
mHandler.postDelayed(mRunnable, 1000);
}
};
private Handler mHandler = new Handler();
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this,"staart",Toast.LENGTH_LONG).show();
mStartTX=0;
mStartRX=0;
mStartRX = TrafficStats.getTotalRxBytes();
mStartTX = TrafficStats.getTotalTxBytes();
mHandler.postDelayed(mRunnable, 1000);
return Service.START_STICKY;
}
#Override
public void onDestroy() {
TrafficStats.clearThreadStatsTag();
Toast.makeText(this,"FirstService Stoped",Toast.LENGTH_LONG).show();
mStartTX=0;
mStartRX=0;
super.onDestroy();
}
}
AndroidManifest :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="ir.alexandre9009.service">
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.UPDATE_DEVICE_STATS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<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">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".FirstService"
>
</service>
</application>
</manifest>
please help me ...

The problem is with this line
public long dl=MainActivity.DLL;
You're referring to a variable in the Activity, surly when the Activity is destroyed, this variable is no longer in scope, thus you get Null Exception.
You must get this value using the intent.
The other problem is that you can't prevent any service from being killed by the system except foreground services which need to show a notification to the user. But this is not suitable for your situation.
Therefore, the best approach for you is to check whether intent is null or not. If it is not null, you get the value and save it into Preferences or Database or somewhere, if it is null, you retrieve the value from where you stored it before.

Activities lifecycle after pushed android button "recents" create new activity but dont destroy old activity

When i push android button "recents" and select my app again to go back to de app, the lifecycle of MapsActivity execute onCreate again and create a new instance of MapsActivity.
That´s ok, but the old MapsActivity still running in background and that´s a problem because both MapsActivity have counters and still running and counting with different values in the same variables, like independent new variables.
The counter is in onLocationChanged() and called as "clock".
onLocationChanged() update automaticaly ever 5 seconds.
example:
counter is running : 1, 2, 3, 4, 5, ...
at this point i push android button "recent" (the system execute onCreate)
counter still running like that : 6, 1, 7, 2, 8, 3, ...
at this point a push again android button "recent" (execute onCreate)
counter still running like that : 9, 4, 1, 10, 5, 2, 11, 6, 3, ...
I suppose the lifecycle of MapsActivity not destroy old activities.
I need only one sequencial counter running, and i guess the old MapsActivity must die :)
any idea to solve my problem ? Thanks a lot!
below the manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sasse.myapplication">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="#string/google_maps_key" />
<activity
android:name=".MapsActivity"
android:label="#string/title_activity_maps">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
layout activity_maps.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.sasse.myapplication.MapsActivity" />
Maps_activity
package com.example.sasse.myapplication;
import android.*;
import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MapsActivity extends FragmentActivity implements LocationListener, ConnectionCallbacks, OnConnectionFailedListener, OnMapReadyCallback {
private static final String TAG = "MapsActivity";
private GoogleMap mMap;
protected GoogleApiClient mGoogleApiClient;
protected LocationRequest mLocationRequest;
public int clock = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkLocationPermission();
}
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
//Initialize Google Play Services
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
} else {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
}
public void onLocationChanged(Location location) {
clock++;
if (clock>=10) {
Toast.makeText(this, "clock : "+clock, Toast.LENGTH_SHORT).show();
clock=0;
}
Log.i(TAG, "= = = = = >>> clock : "+clock);
}
// ---------------------------------------------------------------------------------------------
// ---------------- VERIFICAÇÃO DA CONEXÃO COM O SERVIDOR DO GOOGLE MAPS-----------------------
// ---------------------------------------------------------------------------------------------
public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
public boolean checkLocationPermission() {
if (ContextCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Asking user if explanation is needed
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
android.Manifest.permission.ACCESS_FINE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
//Prompt the user once explanation has been shown
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_LOCATION);
}
return false;
} else {
return true;
}
}
public void onRequestPermissionsResult(int requestCode, #NonNull String permissions[], #NonNull int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted. Do the
// contacts-related task you need to do.
if (ContextCompat.checkSelfPermission(this,
android.Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
if (mGoogleApiClient == null) {
buildGoogleApiClient();
}
mMap.setMyLocationEnabled(true);
}
} else {
// Permission denied, Disable the functionality that depends on this permission.
Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
}
}
// other 'case' lines to check for other permissions this app might request.
// You can add here other case statements according to your requirement.
}
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
public void onConnected(Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(5000);
mLocationRequest.setFastestInterval(5000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
}
public void onConnectionSuspended(int i) {
}
public void onConnectionFailed(#NonNull ConnectionResult connectionResult) {
}
}

Try using launchMode="singleTop" for activity

Activity error even thought its declared in manifest

firsly i want to say i use the 2 Intents i refer in each to change activity between them and i can also move to this class with an intent but when i try to startactivty from this class it crashes .
this is the class where i get the error.
package com.example.wince.myapplication;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.Button;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.ArrayList;
/**
* Created by Wince on 31.05.2016.
*/
public class RotaGoster extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
final Intent rotaIntent = new Intent(this, com.example.wince.myapplication.Rota.class);
final Intent kayitIntent = new Intent(this, com.example.wince.myapplication.RotaKayit.class);
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rota);
String isim = getIntent().getExtras().getString("DB_name");
VeriTabani VT = new VeriTabani(this);
Button Kayit = (Button) findViewById(R.id.button6);
Button Rota = (Button) findViewById(R.id.button7);
int i = 0;
ArrayList<Yer> yerler = new ArrayList<>();
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map2);
mapFragment.getMapAsync(this);
yerler.addAll(VT.getAllYer());
for (i = 0; i < yerler.size(); i++) {
if (yerler.get(i).equals(isim)) {
mMap.addMarker(new MarkerOptions().position(new LatLng(VT.getYer(i).getLat(), VT.getYer(i).getLng())).title(i + "'inci nokta"));
}
}
Kayit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(kayitIntent);
finish();
}
});
Rota.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(rotaIntent);
finish();
}
});
//dbden verileri çekmek gerek
// db işlemleri ve gösterim burda yapılıcak.
}
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
}
}
this is the android manifest.xml file
<?xml version="1.0" encoding="utf-8"?>
<!--
The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
Google Maps Android API v2, but you must specify either coarse or fine
location permissions for the 'MyLocation' functionality.
-->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<!--
The API key for Google Maps-based APIs is defined as a string resource.
(See the file "res/values/google_maps_api.xml").
Note that the API key is linked to the encryption key used to sign the APK.
You need a different API key for each encryption key, including the release key that is used to
sign the APK for publishing.
You can define the keys for the debug and release targets in src/debug/ and src/release/.
-->
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="#string/google_maps_key" />
<activity
android:name=".RotaKayit"
android:label="#string/title_activity_maps">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Rota"></activity>
<activity android:name=".RotaGoster"></activity>
</application>
this is the logcat for error
06-05 15:51:55.032 10275-10275/com.example.wince.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.wince.myapplication, PID: 10275
android.content.ActivityNotFoundException: Unable to find explicit activity class {/com.example.wince.myapplication.Rota}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1636)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1430)
at android.app.Activity.startActivityForResult(Activity.java:3532)
at android.app.Activity.startActivityForResult(Activity.java:3493)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:842)
at android.app.Activity.startActivity(Activity.java:3735)
at android.app.Activity.startActivity(Activity.java:3703)
at com.example.wince.myapplication.RotaGoster$2.onClick(RotaGoster.java:55)
at android.view.View.performClick(View.java:4633)
at android.view.View$PerformClick.run(View.java:19274)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5593)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)

changing the code like this ; putting intent declarations in the oncreate method seems to solve the problem
package com.example.wince.myapplication;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.Button;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.ArrayList;
/**
* Created by Wince on 31.05.2016.
*/
public class RotaGoster extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rota);
String isim = getIntent().getExtras().getString("DB_name");
VeriTabani VT = new VeriTabani(this);
Button Kayit = (Button) findViewById(R.id.button6);
Button Rota = (Button) findViewById(R.id.button7);
int i = 0;
final Intent rotaIntent = new Intent(this, Rota.class);
final Intent kayitIntent = new Intent(this, RotaKayit.class);
ArrayList<Yer> yerler = new ArrayList<>();
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map2);
mapFragment.getMapAsync(this);
yerler.addAll(VT.getAllYer());
for (i = 0; i < yerler.size(); i++) {
if (yerler.get(i).equals(isim)) {
mMap.addMarker(new MarkerOptions().position(new LatLng(VT.getYer(i).getLat(), VT.getYer(i).getLng())).title(i + "'inci nokta"));
}
}
Kayit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(kayitIntent);
finish();
}
});
Rota.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(rotaIntent);
finish();
}
});
//dbden verileri çekmek gerek
// db işlemleri ve gösterim burda yapılıcak.
}
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
}
}

You have a reference to this outside of the instance, so you can only declare the Intents as fields, but you must initialize them in onCreate or later.
They also don't need to be final.

Java RuntimeException "Fail to connect to camera service"

I have looked at many questions similar to mine on stackoverflow and other websites but have not been able to find a solution for my problem. I have requested the correct permissions but I still am getting this error. At first I thought it was because I was using an AVD but even while using a phone I still get this error.
MainActivity:
package com.example.vishal.textfacialprocessing;
import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;
import com.qualcomm.snapdragon.sdk.face.FaceData;
import com.qualcomm.snapdragon.sdk.face.FacialProcessing;
public class MainActivity extends Activity implements Camera.PreviewCallback {
Camera mCamera = null;
CameraPreview preview;
private CameraPreview mPreview = null;
private int cameraside = 1;
private int Front_Camera_Index = 1;
private int Back_Camera_Index = 0;
private static boolean switchCamera;
private boolean _qcSDKEnabled;
FacialProcessing faceProc;
Display display;
private int displayAngle;
private int numFaces;
FaceData[] faceArray = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button switchCameraButton = (Button)
findViewById(R.id.switchCamera);
switchCameraButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (cameraside == 1) {
cameraside = 0;
} else {
cameraside = 1;
}
}
});
setCamera();
}
public void setCamera ()
{
mCamera = Camera.open(cameraside);
mPreview = new CameraPreview(MainActivity.this,mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview);
mCamera.setPreviewCallback(MainActivity.this);
_qcSDKEnabled = FacialProcessing.isFeatureSupported(FacialProcessing.FEATURE_LIST.FEATURE_FACIAL_PROCESSING);
}
}
CameraPreview:
package com.example.vishal.textfacialprocessing;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.ViewGroup;
import com.qualcomm.snapdragon.sdk.face.FacialProcessing;
import java.io.IOException;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera cameraObj;
public CameraPreview(Context context, Camera camera) {
super(context);
cameraObj = camera;
// Install a urfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
// SurfaceHolder jholder = holder;
// The Surface has been created, now tell the camera where to draw the preview.
try {
cameraObj.setPreviewDisplay(holder);
cameraObj.startPreview();
} catch (IOException e) {
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
cameraObj.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
try {
cameraObj.setPreviewDisplay(mHolder);
cameraObj.startPreview();
} catch (Exception e){
}
}
}
Manifest:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Logicat:
01-02 14:27:35.261 10635-10635/com.example.vishal.textfacialprocessing E/Typeface: SANS_LOC file not found.
01-02 14:27:35.321 10635-10635/com.example.vishal.textfacialprocessing E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.vishal.textfacialprocessing, PID: 10635
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.vishal.textfacialprocessing/com.example.vishal.textfacialprocessing.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.hardware.Camera.release()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2411)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2474)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1359)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:155)
at android.app.ActivityThread.main(ActivityThread.java:5696)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.hardware.Camera.release()' on a null object reference
at com.example.vishal.textfacialprocessing.MainActivity.getCameraInstance(MainActivity.java:156)
at com.example.vishal.textfacialprocessing.MainActivity.onResume(MainActivity.java:58)
at com.example.vishal.textfacialprocessing.MainActivity.onCreate(MainActivity.java:50)
at android.app.Activity.performCreate(Activity.java:5958)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1129)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2474) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1359) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:155) 
at android.app.ActivityThread.main(ActivityThread.java:5696) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824) 

Hi Vishal you need to add following permission in menifest file
<uses-permission android:name="android.permission.CAMERA" />
If you are using the Android M permission model, you first need to check if the app has this permission during runtime, and have to prompt the user for this permission during runtime. The permission you define on your manifest will not automatically be granted on install time.
if (checkSelfPermission(Manifest.permission.CAMERA)
!= PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.CAMERA},
MY_REQUEST_CODE);
}
You will need a callback for the dialog result:
#Override
public void onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == MY_REQUEST__CODE) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Now user should be able to use camera
}
else {
// Your app will not have this permission. Turn off all functions
// that require this permission or it will force close like your
// original question
}
}
}