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getStringArrayExtra() returns null

I am trying to create an android app on android studio which scans WIFI signals, and passes all the WIFI signal SSIDs containing "WDT_" to another intent.
When I run the app, it crashes due to a NPE.
I debugged the app, and it says that intent.getStringArrayExtra() in MultipleWifi.java is null.
Am I doing something wrong with passing the string array?
MainActivity.java:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WifiManager wifiManager = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
WifiConfiguration conf = new WifiConfiguration();
int WDTWifiCount = 0;
List<ScanResult> results = wifiManager.getScanResults();
for (ScanResult scanResult : results) {
if (scanResult.SSID.contains("WDT_")) {
SSIDString[0] = (scanResult.SSID);
WDTWifiCount++;
}
}
WDTWifiCount = 2;
SSIDString[0] = "WDT_12345";
SSIDString[1] = "WDT_14445";
if (WDTWifiCount < 1) {
startActivity(new Intent(this, NoWifi.class));
} else if (WDTWifiCount > 1) {
Intent intent = new Intent(this, MultipleWifi.class);
intent.putExtra("SSIDList", SSIDString);
startActivityForResult(intent, 1);
}
conf.SSID = "\"" + networkSSID + "\"";
conf.preSharedKey = "\"" + networkPass + "\"";
WDTWifiCount = 0;
wifiManager.addNetwork(conf);
List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for (WifiConfiguration i : list) {
if (i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"") && WDTWifiCount != 0) {
wifiManager.disconnect();
wifiManager.enableNetwork(i.networkId, true);
wifiManager.reconnect();
break;
}
}
myWebView = new WebView(this);
myWebView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
webSettings.setLoadWithOverviewMode(true);
webSettings.setUseWideViewPort(true);
webSettings.setSupportZoom(true);
webSettings.setBuiltInZoomControls(true);
myWebView.setWebChromeClient(new WebChromeClient());
myWebView.loadUrl("http://192.168.1.1/index.html");
}
MultipleWifi.java:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.multiplewifi);
Intent intent = getIntent();
final String[] StringSSID = intent.getStringArrayExtra("SSIDstring");
List<String> SSIDList = new ArrayList<String>(Arrays.asList(StringSSID));
final Spinner spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, SSIDList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String SSID = spinner.getSelectedItem().toString();
Intent intent = new Intent();
intent.putExtra("SSID", SSID);
setResult(RESULT_OK, intent);
finish();
}
});
}
Debug:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.wdt, PID: 9031
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.wdt/com.example.wdt.MultipleWifi}: java.lang.NullPointerException: storage == null
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2200)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1200)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException: storage == null
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:155)
at com.example.wdt.MultipleWifi.onCreate(MultipleWifi.java:23)
at android.app.Activity.performCreate(Activity.java:5275)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2164)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250) 
at android.app.ActivityThread.access$800(ActivityThread.java:139) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1200) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:136) 
at android.app.ActivityThread.main(ActivityThread.java:5105) 
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:792) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608) 
at dalvik.system.NativeStart.main(Native Method) 
EDIT: After editing the key in "intent.putExtra" to SSIDString it still returns null.
Debug:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.wdt, PID: 31443
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.wdt/com.example.wdt.MultipleWifi}: java.lang.NullPointerException: storage == null
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2200)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1200)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException: storage == null
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:155)
at com.example.wdt.MultipleWifi.onCreate(MultipleWifi.java:23)
at android.app.Activity.performCreate(Activity.java:5275)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2164)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250) 
at android.app.ActivityThread.access$800(ActivityThread.java:139) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1200) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:136) 
at android.app.ActivityThread.main(ActivityThread.java:5105) 
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:792) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608) 
at dalvik.system.NativeStart.main(Native Method) 

You are using wrong key
Intent intent = new Intent(this, MultipleWifi.class);
intent.putExtra("SSIDList", SSIDString);
there is key that you are passing
startActivityForResult(intent, 1);
//change key you are using wrong key here
final String[] StringSSID = intent.getStringArrayExtra("SSIDList");

First take the user permisison!
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
PERMISSIONS_REQUEST_CODE_ACCESS_COARSE_LOCATION);
//After this point you wait for callback in onRequestPermissionsResult(int, String[], int[]) overriden method
}else{
getScanningResults();
//do something, permission was previously granted; or legacy device
}

My app keeps crashing but has no errors in it

I am new to Android and Java programming and for some reason (I cant point out) my app wont even open.It says "Unfortunately 'app name' has crashed". It has no compile-time errors in it?
Here is the Logcat:
08-19 04:54:07.024 24170-24170/com.elie.billsplitter E/AndroidRuntime﹕FATAL EXCEPTION: main
Process: com.elie.billsplitter, PID: 24170
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.elie.billsplitter/com.elie.billsplitter.MainActivity}: java.lang.NumberFormatException: Invalid int: ""
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
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:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.NumberFormatException: Invalid int: ""
at java.lang.Integer.invalidInt(Integer.java:138)
at java.lang.Integer.parseInt(Integer.java:358)
at java.lang.Integer.parseInt(Integer.java:334)
at com.elie.billsplitter.MainActivity.<init>(MainActivity.java:11)
at java.lang.reflect.Constructor.newInstance(Native Method)
at java.lang.Class.newInstance(Class.java:1606)
at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
            at android.app.ActivityThread.access$800(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5257)
            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:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
08-19 04:54:09.781 24170-24177/com.elie.billsplitter W/art﹕ Suspending all threads took: 793.743ms
08-19 04:54:36.935 24170-24170/com.elie.billsplitter I/Process﹕ Sending signal. PID: 24170 SIG: 9
Here is the Java file:
public class MainActivity extends Activity {
public int x = Integer.parseInt("");
public int y = Integer.parseInt("");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Button
Button btn = (Button) findViewById(R.id.button);
//EditText
EditText nop = (EditText) findViewById(R.id.editText);
EditText cob = (EditText) findViewById(R.id.editText2);
x = Integer.parseInt(nop.getText().toString());
y = Integer.parseInt(cob.getText().toString());
final TextView tv = (TextView) findViewById(R.id.textView);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int z = x / y;
tv.setText(z);
}
});
}
}

Most probably you are parsing an empty string into the integer.
x = Integer.parseInt(nop.getText().toString());
y = Integer.parseInt(cob.getText().toString());
before getting the text from the Edittext check that whether it is empty or not. You are parsing an empty string probably.
you can make a check like this:
if(!(nop.toString().trim().equalsIgnoreCase("") && cob.toString().trim().equalsIgnoreCase(""))){
x = Integer.parseInt(nop.getText().toString());
y = Integer.parseInt(cob.getText().toString());
}
and also your are making the initilization the integers in an incorrect way:
May be these are the lines where you are getting exceptions. You cannot parse blank strings to integer.
instead of this:
public int x = Integer.parseInt("");
public int y = Integer.parseInt("");
write this:
public int x = 0;
public int y = 0;
or
public int x = Integer.parseInt("0");
public int y = Integer.parseInt("0");

Before converting to a number you can check if it is a numeric string. For some ideas read this thread on stackoverflow: How to check if a String is numeric in Java

Somewhere in your code you are converting a invalid string or a empty string into a number, which is causing the NumberFormatException.
String x = "abc";
int num = Integer.parseInt(x);
How do I solve it?
try
{
String x = "abc";
int num = Integer.parseInt(x);
}
catch(NumberFormatException ne)
{
System.out.println("Invalid Number!");
}

In your code, replace:
public int x = Integer.parseInt("");
public int y = Integer.parseInt("");
with
public int x;
public int y;
The default values of x and y will be 0. You don't have to add that.
Reason of Error: Integer.parseInt() converts the string inside it to an integer. You have tried to convert "" to an integer, which is not even a number... So NumberFormatException occurred.

android Unable to start activity ComponentInfo NULL Point Exception

My app work strange on diffrent phones - once everything is fine and other time it crash when i try to make photo and save it in my phone's memory. Photo shows up in folder in memory, but when we should come back to application it is shut down:
06-14 23:58:37.448 12344-12344/com.apps.madzia.photo_application E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.apps.madzia.photo_application, PID: 12344
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.apps.madzia.photo_application/com.apps.madzia.photo_application.activity.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2412)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2470)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4053)
at android.app.ActivityThread.access$1000(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
at android.os.Handler.dispatchMessage(Handler.java:102)
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)
Caused by: java.lang.NullPointerException
at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
at android.widget.GridView.setAdapter(GridView.java:187)
at com.apps.madzia.photo_application.fragments.FragmentGallery.onCreateView(FragmentGallery.java:42)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1917)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:544)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1177)
at android.app.Activity.performStart(Activity.java:5468)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2385)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2470)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4053)
            at android.app.ActivityThread.access$1000(ActivityThread.java:174)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            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)
The code of my function to make photos:
public void make_photo() {
Calendar c;
c = Calendar.getInstance();
imageName = "fotka_" + c.get(Calendar.YEAR) + "_" + c.get(Calendar.MONTH) + "_" + c.get(Calendar.DAY_OF_MONTH)
+ "_" + c.get(Calendar.HOUR_OF_DAY) + "_" + c.get(Calendar.MINUTE) + "_" + c.get(Calendar.SECOND);
File katalog = new File(IMAGE_FILE_PATH);
File photo = new File(IMAGE_FILE_PATH+imageName + ".jpg");
if( Environment.getExternalStorageState() == Environment.MEDIA_UNKNOWN || Environment.getExternalStorageState() == Environment.MEDIA_REMOVED || Environment.getExternalStorageState() == Environment.MEDIA_UNMOUNTED) {
Log.d("ExternalStorage", "cannot find memory SD card");
File file = new File(getFilesDir(), imageName);
IMAGE_FILE_PATH = file.getParent()+"/";
Log.d("IMAGE_FILE_PATH", IMAGE_FILE_PATH);
}else {
}
Log.d("photo", photo.getPath());
if (!katalog.exists()) {
katalog.mkdirs();
}
try {
// fotka = File.createNewFile(imageName, ".jpg", katalog);
photo.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
Intent zdjecie = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
zdjecie.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
startActivityForResult(zdjecie, 1);
}

Caused by: java.lang.NullPointerException
at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
at android.widget.GridView.setAdapter(GridView.java:187)
at com.apps.madzia.photo_application.fragments.FragmentGallery.onCreateView(FragmentGallery.java:42)
This means that in your FragmentGallery in onCreateView method on line 42 u are setting null ArrayAdapter

How can i solve getApplicationContext() java.lang.NullPointerExeception

I am trying to connect to an azure application, using android, but I am getting this error. Here is my code and my logs.
I have checked everything and it seen to be right, but the problem I think is with getApplicationContext(). I am unable to debug.
can someone help me please?
public class login extends Activity {
UserServicesImpl usv;
private EditText txtemail;
private EditText txtpassword;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
txtemail = (EditText) findViewById(R.id.txtemail);
txtpassword = (EditText) findViewById(R.id.txtpassword);
}
public void LoginKarrega(View view){
usv = new UserServicesImpl();
AlertDialog alertDialog = new AlertDialog.Builder(login.this).create();
alertDialog.setTitle("Alert");
if(usv.exist(txtemail.getText().toString(), txtpassword.getText().toString()) == true) {
alertDialog.setMessage("Sucessful login");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
}
else {
alertDialog.setMessage("wrong login");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
}
alertDialog.show();
}
#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_login, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Logcat:
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4007)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
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:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
at android.content.ContextWrapper.getApplicationContext(ContextWrapper.java:105)
at com.microsoft.windowsazure.mobileservices.notifications.MobileServicePush.<init>(MobileServicePush.java:134)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.initialize(MobileServiceClient.java:1473)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.<init>(MobileServiceClient.java:182)
at com.microsoft.windowsazure.mobileservices.MobileServiceClient.<init>(MobileServiceClient.java:158)
at ao.co.karrega.services.customers.UserServicesImpl.<init>(UserServicesImpl.java:39)
at ao.co.karrega.login.LoginKarrega(login.java:32)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

Use below code to solve this error. Currently you are using this instead of getApplicationContext().
try {
mClient = new MobileServiceClient(
"https://newvbdemo.azure-mobile.net/",
"SUFYiOYEAlbEoKfsDgfWNIywaPSMhC29",
getApplicationContext()
);
mTable = mClient.getTable("Users",Users.class);
}catch (MalformedURLException e) {
e.printStackTrace();
}

Your class UserServicesImpl extends Activity but it does not seem to be an Activity.
In particular, activities usually don't have an explicit constructor, and you cannot use an Activity as a Context before its onCreate() lifecycle method. Construction phase <init> in your stacktrace is too early.
The stacktrace also shows that you're trying to instantiate an activity with new in LoginKarrega. Never instantiate an activity with new yourself.
Looks like you should be removing the extends Activity and pass a Context as an argument instead.

MediaPlayer with Internal Files

I'm trying to select an audio file from internal storage, which I then create a media player from.
public void openPressed(View view) {
Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Audio.Media.INTERNAL_CONTENT_URI);
startActivityForResult(intent, 1);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (data != null) {
MediaPlayer player = MediaPlayer.create(this, data.getData());
player.start();
}
}
All of this is in my main activity, but after selecting a file, the app crashes.
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/audio/media/29 }} to activity {com.malik.mixtape/com.malik.mixtape.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaPlayer.start()' on a null object reference
at android.app.ActivityThread.deliverResults(ActivityThread.java:3539)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3582)
at android.app.ActivityThread.access$1300(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1327)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
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:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaPlayer.start()' on a null object reference
at com.malik.mixtape.MainActivity.onActivityResult(MainActivity.java:65)
at android.app.Activity.dispatchActivityResult(Activity.java:6135)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3535)
            at android.app.ActivityThread.handleSendResult(ActivityThread.java:3582)
            at android.app.ActivityThread.access$1300(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1327)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

Try to do this instead, I am assuming that data.getData() returns the path to the file,
MediaPlayer player = new MediaPlayer();
player.setOnPreparedListener(mPreparedListener);
player.setDataSource(MyActivity.this, Uri.fromFile(new File(data.getData())));
MediaPlayer.OnPreparedListener mPreparedListener = new MediaPlayer.OnPreparedListener()
{
/** Called when MediaPlayer is ready */
public void onPrepared(MediaPlayer player)
{
player.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
player.start();
}
};