Null Pointer Exception on EditText to String

Question

I have an EditText in which I get numbers and need to convert them to a float but still get the same eror - Null Pointer Exception.

This is my code:

public class Basic extends Fragment implements AdapterView.OnItemSelectedListener {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {


        View view = inflater.inflate(R.layout.basic, container, false);
        Spinner spinnerLenght = (Spinner) view.findViewById(R.id.spinnerLenght);
        spinnerLenght.setOnItemSelectedListener(this);
        ArrayAdapter<String> lenghtAdapter;
        lenghtAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.basic_string_lenght));
        lenghtAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerLenght.setAdapter(lenghtAdapter);

        return view;
    }


    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        String itemLenght = parent.getItemAtPosition(position).toString();
        EditText editTextLenght = (EditText) view.findViewById(R.id.editTextLenght);
        float floatLenght;
        floatLenght = Float.parseFloat(editTextLenght.getText().toString());
        float result_mm = 0;
        if (itemLenght.equals("mm")){


            result_mm = floatLenght * 1000;
        }


        Toast.makeText(parent.getContext(), (int) result_mm, Toast.LENGTH_LONG).show();
    }




    @Override
    public void onNothingSelected(AdapterView<?> parent) {

    }
}

This is logcat :

E/AndroidRuntime: FATAL EXCEPTION: main
                                                                      Process: com.example.dusan.unit, PID: 5181
                                                                      java.lang.NullPointerException
                                                                          at com.example.dusan.unit.Basic.onItemSelected(Basic.java:46)
                                                                          at android.widget.AdapterView.fireOnSelected(AdapterView.java:956)
                                                                          at android.widget.AdapterView.access$200(AdapterView.java:49)
                                                                          at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:920)
                                                                          at android.os.Handler.handleCallback(Handler.java:733)
                                                                          at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                          at android.os.Looper.loop(Looper.java:157)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5356)
                                                                          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:1265)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
                                                                          at dalvik.system.NativeStart.main(Native Method)

I tried it on a double too. I also had problem with null = "" I read a lot about this but can`t find solution.

score 0 · Answer 1 · answered May 23 '17 at 21:37

0

1)Check if you wrote correct id of your editText; 2)Find your editText in onCreateView from inflated layout or make your layout view as class variable and then find your edit text from her in onItemClick

answered May 23 '17 at 21:37

Vanya Makhlinets

248
1
4
13

I use tabbed activity here.And i don`t have onCreate here i have onCreateView and someone told me that is problem.Is that right? – Dusan Culum May 23 '17 at 21:40
@DusanCulum The tabbed activity does have `onCreate`. The fragment in a tab has `onCreateView`, but that is not the problem – OneCricketeer May 23 '17 at 21:42

OneCricketeer · Answer 2 · 2017-05-23T22:02:39.847

0

Main problem

You are using the wrong ID and class.

EditText editTextLenght = (EditText) view.findViewById(R.id.editTextLenght);

The correct ID is android.R.id.text1.
The correct class is TextView.

See What is "android.R.layout.simple_list_item_1"? since that is the layout you set in the adapter.

Alternate solution

If the problem is parent.getItemAtPosition(position).toString();, then don't use that.

If you want to access the data in the adapter, then move it to a scope that you can access using a member variable

public class Basic extends Fragment implements AdapterView.OnItemSelectedListener {

    private ArrayAdapter<String> lenghtAdapter;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.basic, container, false);
        Spinner spinnerLenght = (Spinner) view.findViewById(R.id.spinnerLenght);
        spinnerLenght.setOnItemSelectedListener(this);
        this.lenghtAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.basic_string_lenght));

Then, use getItem method rather than trying to find the view

float floatLenght = Float.parseFloat(lenghtAdapter.getItem(position));

Also, please spell length correctly

edited May 23 '17 at 22:02

answered May 23 '17 at 21:38

OneCricketeer

179,855
19
132
245

Still have problem logcat: java.lang.NullPointerException at com.example.dusan.unit.Basic.onItemSelected(Basic.java:39) ( String itemLenght = spinnerLenght.getSelectedItem().toString();) – Dusan Culum May 23 '17 at 21:50
`spinnerLenght` is not accessible within `onItemSelected` from your question, and that code you pasted doesn't match the question. So that is a **new** error, not the same – OneCricketeer May 23 '17 at 21:53
FATAL EXCEPTION: main Process: com.example.dusan.unit, PID: 24497 java.lang.ClassCastException: android.support.v7.widget.AppCompatTextView cannot be cast to android.widget.EditText at com.example.dusan.unit.Basic.onItemSelected(Basic.java:44) 44 is this :EditText editTextLenght = (EditText) view.findViewById(android.R.id.text1); – Dusan Culum May 23 '17 at 21:54
That makes sense... It's not an editable text field. Please try the *alternate solution*, then. – OneCricketeer May 23 '17 at 22:01
But in Spinner i chose mm cm or m so i need it first as string for if (itemLenght.equals("mm")){ result_mm = floatLenght * 1000; } – Dusan Culum May 23 '17 at 22:06

score 0 · Answer 3 · edited May 24 '17 at 04:12

0

Look at main(you asked) problem, you want convert the number to float from the EditText.

First import: import android.widget.EditText;

EditText editTextLenght = (EditText) View.findViewById(R.id.editTextLenght);

floatLenght = Float.parseFloat(editTextLenght.getText().toString());
//this code used in java programs.in android you can use below

try{
   float floatLenght =  Float.valueOf(editTextLenght.getText().toString());
} catch (NumberFormatException e) {
   e.printStackTrace();
}

float(first letter is small) is primitive type and Float is wrapper class use to conversion from string to float. You don't need to change other code.

edited May 24 '17 at 04:12

Satan Pandeya

3,747
4
27
53

answered May 23 '17 at 23:16

najmudheen

1
2

java.lang.NullPointerException at com.example.dusan.unit.Basic.onItemSelected(Basic.java:53) that is float floatLenght = Float.valueOf(editTextLenght.getText().toString()); – Dusan Culum May 24 '17 at 11:00

Null Pointer Exception on EditText to String

3 Answers3

Main problem

Alternate solution