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

Question

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)

why @Pooja ? I am showing the activity and the log, what else do you need ? — Evanilson Abril, Apr 21 '15 at 05:25
Where is the code where you trying to get `getApplicationContext()` — Pooja, Apr 21 '15 at 05:26
Are you sure error is in this class, I am to able to see the use of getApplicationContext any where in the code.. — keshav kowshik, Apr 21 '15 at 05:26
Ya thats the point @Pooja I don't have it in my all code but it is saying that on the logs — Evanilson Abril, Apr 21 '15 at 05:29
@keshav1234 I have edited the code can you take a look again please ? — Evanilson Abril, Apr 21 '15 at 05:29
@Keshav1234 it is a class that connect to the azure mobile application, retrieve the data from the data base that is associated with the application mobile, and has a method exist to check if the email and password passed matches with any record on the database — Evanilson Abril, Apr 21 '15 at 05:39
where is your button on which you are calling LoginKarrega() check out is this correct in your xml — Prashant Bhoir, Apr 21 '15 at 05:45
Yes @Prashant Bhoir, the button on the xml has this android:onClick="LoginKarrega" — Evanilson Abril, Apr 21 '15 at 05:46

score 0 · Answer 1 · answered Apr 21 '15 at 05:26

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();
    }

score 0 · Answer 2 · answered Apr 21 '15 at 05:26

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.

Mr. @laalto I have updated it can you take a look again please? — Evanilson Abril, Apr 21 '15 at 05:27

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

2 Answers2