Spinner throws NullPointerException when calling an entries value

Question

I have a Spinner in my ActionBar, I want to get the value of the entries in the Spinner when I pick one and convert it to String. It is thorwing NullPointerException every time I start the Activity. How do I fix this?

I have read many guides and stackoverflow questions but I can't find anything that is simpler and near my case. Here is the code.

spinner.xml

<Spinner
    android:id="@+id/SpinnerTerms"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:entries="@array/pmf"/>

menu_classviewstudents.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" tools:context=".ClassViewStudents">

    <item android:id="@+id/ViewStudentsClassesMenu"
        android:showAsAction="ifRoom|withText"
        android:icon="@drawable/addstudents"
        android:menuCategory="container"
        android:title="Add"/>

   <item android:id="@+id/AddGrades"
       android:showAsAction="ifRoom"
       android:actionLayout="@layout/spinner"
       android:title="Grades"/>

</menu>

array.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="pmf">
        <item>Prelim</item>
        <item>Midterm</item>
        <item>Finals</item>
    </string-array>

</resources>

This is my onCreate where I call my Spinner and put the entries value in a string:

protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.classes_view);

        SpinnerPMF = (Spinner) findViewById(R.id.SpinnerTerms);

        spinnervalue = SpinnerPMF.getItemAtPosition(SpinnerPMF.getSelectedItemPosition()).toString();

        db = openOrCreateDatabase("ClassManager", MODE_WORLD_WRITEABLE, null);

        reciever = getIntent().getStringExtra("sender");

        Cursor c = db.rawQuery("SELECT * FROM '" + reciever + "'", null);

        int count= c.getCount();
        c.moveToFirst();
        TableLayout tableLayout = new TableLayout(getApplicationContext());
        tableLayout.setVerticalScrollBarEnabled(true);
        tableLayout.setHorizontalScrollBarEnabled(true);

        RelativeLayout rl=(RelativeLayout)findViewById(R.id.layout3);
        ScrollView sv = new ScrollView(this);
        sv.setHorizontalScrollBarEnabled(true);
        sv.addView(tableLayout);
        rl.addView(sv, new WindowManager.LayoutParams(WindowManager.LayoutParams.FILL_PARENT, WindowManager.LayoutParams.FILL_PARENT));


        for (Integer j = 0; j < count; j++)
        {
            tableRow = new TableRow(getApplicationContext());
            textView1 = new TextView(getApplicationContext());
            textView1.setText(c.getString(c.getColumnIndex("StudentID")));
            textView1.setPadding(20, 20, 20, 20);
            textView1.setTextColor(getResources().getColor(R.color.redactionbar));
            textView1.setTextSize(TypedValue.COMPLEX_UNIT_DIP,25);
            textView1.setTypeface(null, Typeface.BOLD);
            tableRow.addView(textView1);

            final TableRow finalTableRow = tableRow;

            textView = new TextView(getApplicationContext());
            textView.setText(c.getString(c.getColumnIndex("LastName")));
            textView.setPadding(20, 20, 20, 20);
            textView.setTextColor(getResources().getColor(R.color.redactionbar));
            textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP,25);
            textView.setTypeface(null, Typeface.BOLD);
            tableRow.addView(textView);
            tableLayout.addView(tableRow);

            tableRow.setOnClickListener(new View.OnClickListener()
            {
                @Override
                public void onClick(View view)
                {

                    Toast toast = Toast.makeText(getApplicationContext(), spinnervalue, Toast.LENGTH_SHORT);
                    toast.show();

                    /*
                    if(SpinnerValue == "Prelim")
                    {
                        Toast toast = Toast.makeText(getApplicationContext(), "Prelim Selected", Toast.LENGTH_SHORT);
                        toast.show();
                    }

                    else if (SpinnerValue == "Midterm")
                    {
                        Toast toast = Toast.makeText(getApplicationContext(), "Midterm Selected", Toast.LENGTH_SHORT);
                        toast.show();
                    }

                    else if (SpinnerValue == "Finals")
                    {
                        Toast toast = Toast.makeText(getApplicationContext(), "Finals Selected", Toast.LENGTH_SHORT);
                        toast.show();
                    }
                    */
                }
            });

            c.moveToNext() ;
        }
        rl.requestLayout();
        db.close();

    }

Here is the logcat error:

02-16 14:10:29.784: E/AndroidRuntime(29837): FATAL EXCEPTION: main
02-16 14:10:29.784: E/AndroidRuntime(29837): Process: test.com.classmanagertest, PID: 29837
02-16 14:10:29.784: E/AndroidRuntime(29837): java.lang.RuntimeException: Unable to start activity ComponentInfo{test.com.classmanagertest/test.com.classmanagertest.ClassViewStudents}: java.lang.NullPointerException
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2318)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2396)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread.access$800(ActivityThread.java:139)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1293)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.os.Handler.dispatchMessage(Handler.java:102)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.os.Looper.loop(Looper.java:149)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread.main(ActivityThread.java:5257)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at java.lang.reflect.Method.invokeNative(Native Method)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at java.lang.reflect.Method.invoke(Method.java:515)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at dalvik.system.NativeStart.main(Native Method)
02-16 14:10:29.784: E/AndroidRuntime(29837): Caused by: java.lang.NullPointerException
02-16 14:10:29.784: E/AndroidRuntime(29837):    at test.com.classmanagertest.ClassViewStudents.onCreate(ClassViewStudents.java:43)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.Activity.performCreate(Activity.java:5411)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
02-16 14:10:29.784: E/AndroidRuntime(29837):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)
02-16 14:10:29.784: E/AndroidRuntime(29837):    ... 11 more

indicate line 43 @ `ClassViewStudents` , post `onCreate` method too — Shayan Pourvatan, Feb 16 '15 at 07:43
@Kreyah: what is line number `43` in ClassViewStudents.java ? — ρяσѕρєя K, Feb 16 '15 at 07:47
@shayanpourvatan: spinnervalue = SpinnerPMF.getSelectedItem().toString(); is the line 43 and added OnCreate — BlackEmpiricist, Feb 16 '15 at 08:23
@Kreyah: dear very easy you are passing wrong layout in `setContentView` becuase spinner is in `menu_classviewstudents` layout but you are passing `classes_view` in `setContentView` — ρяσѕρєя K, Feb 16 '15 at 08:28
@ρяσѕρєяK: Ahh Ok. My Spinner is inserted in my Action Bar. I want to get the entry values of my spinner even though it is in my Action Bar. What code should I write? — BlackEmpiricist, Feb 16 '15 at 08:30
Look at my tableRow OnClickListener at OnCreate. I just want to check if the values are being called by the string to make if statements. — BlackEmpiricist, Feb 16 '15 at 08:34

ρяσѕρєя K · Accepted Answer · 2015-02-16T09:10:51.243

1

I have a Spinner in my ActionBar, I want to get the value of the entries in the Spinner when I pick one and convert it to String

if Spinner is inside ActionBar then use onCreateOptionsMenu for setting selected values:

private String SpinnerSelectedValue="";
@Override
public boolean onCreateOptionsMenu(Menu menu) {
   MenuInflater inflater = getMenuInflater();
   inflater.inflate(R.menu.menu_classviewstudents, menu);
   MenuItem item = menu.findItem(R.id.AddGrades);
   SpinnerPMF = (Spinner)item.getActionView();
   SpinnerPMF.setOnItemSelectedListener(new OnItemSelectedListener() {

     @Override
     public void onItemSelected(AdapterView<?> parentView, View selectedItemView, 
                                                         int position, long id) {
       SpinnerSelectedValue=parentView.getItemAtPosition(position).toString();
    }

  });
 return true;
}

Now use SpinnerSelectedValue for getting selected value inside onClick of table Row.

edited Feb 16 '15 at 09:10

answered Feb 16 '15 at 08:43

ρяσѕρєя K

132,198
53
198
213

parent in parent.getItemAtPosition says an error Cannot resolve symbol. – BlackEmpiricist Feb 16 '15 at 09:00
@Kreyah: Use `parentView` instead of `parent` – ρяσѕρєя K Feb 16 '15 at 09:01
I'm still getting a Null Pointer Exception error. at line 126 which is SpinnerPMF = (Spinner)item.getActionView(); – BlackEmpiricist Feb 16 '15 at 09:05
@Kreyah: change `MenuItem item = menu.findItem(R.id.SpinnerTerms);` to `MenuItem item = menu.findItem(R.id.AddGrades);` – ρяσѕρєя K Feb 16 '15 at 09:10
It's working! Finally! This code is so simple yet I find it hard to research about it. Thank you for your efforts! – BlackEmpiricist Feb 16 '15 at 09:14
@ρяσѕρєяK I have a smiliar question here: https://stackoverflow.com/questions/49341522/nullpointerexception-raised-when-calling-adapterview-on-itemselectedlistener-for?noredirect=1#comment85683853_49341522 Can you please help me? – Tia Mar 17 '18 at 21:22

score 0 · Answer 2 · answered Feb 16 '15 at 07:08

0

First check your spinner that it contains value.If it doesn't have values,You have to array into your spinner.

Use this line

String[] mTestArray =   getResources().getStringArray(R.array.pmf);
SpinnerPMF.setAdapter(new ArrayAdapter<String>(context,android.R.layout.sipmle_spinner_item,mTestArray))

after

SpinnerPMF = (Spinner) findViewById(R.id.SpinnerTerms);

this line

I hope this will help to you

answered Feb 16 '15 at 07:08

user3515851

469
1
4
14

I tried the test array after the SpinnerPMF = (Spinner) findViewById(R.id.SpinnerTerms); Still has the same error (Null Pointer Exception) – BlackEmpiricist Feb 16 '15 at 08:18

Spinner throws NullPointerException when calling an entries value

spinner.xml

menu_classviewstudents.xml

array.xml

2 Answers2