nullpointerexception error I know which line has error but how can I fix?

Question

I have looked nullpointerexception error but I can not find a solution for my codes I have googled it but there is not solution. you can see my codes below

public class oyuncuAdlariActivity extends AppCompatActivity {
Button kaleciKayit;
Button oyuncuKayit;
EditText isimGiris;
String isimGirisString;
int kaleciSayisi = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_oyuncu_adlari);
    kaleciKayit = (Button) findViewById(R.id.kaleciButton);
    oyuncuKayit = (Button) findViewById(R.id.oyuncuButton);
    isimGiris = (EditText) findViewById(R.id.isimGir);
    kaleciKayit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            kaleciSayisi++;
            isimGirisString = isimGiris.getText().toString();
            if (isimGirisString.isEmpty()){
                Toast toast1 = Toast.makeText(getApplicationContext(),getApplicationContext().getString(R.string.isimBos), Toast.LENGTH_SHORT);
                toast1.show();
            }
            else if (kaleciSayisi >2)
                kaleciKayit.setEnabled(false);
        }
    });
}

} when I checked logcat it says line 24 has "nullpointexception" problem line 24 is

kaleciKayit.setOnClickListener(new View.OnClickListener() {

what is wrong with this? and I checked layouts they are true here is activity_oyuncu_adlari.xml file

    <Button
        android:id="@+id/oyuncuButton"
        android:layout_width="227dp"
        android:layout_height="52dp"
        android:text="@string/oyuncu_olarak_kaydet"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.434" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/isimleri_buraya_girin"
        android:textSize="20sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.497"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.133" />

    <EditText
        android:id="@+id/isimGir"
        android:layout_width="227dp"
        android:layout_height="52dp"
        android:ems="10"
        android:importantForAutofill="no"
        android:inputType="textPersonName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.188" />

    <Button
        android:id="@+id/kaleciButton"
        android:layout_width="227dp"
        android:layout_height="52dp"
        android:text="@string/kaleci"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.313" />

What does this `kaleciKayit = (Button) findViewById(R.id.kaleciButton);` return? I'm betting that it returns null since you may have not defined kaleciButton correctly in the XML file. — Hovercraft Full Of Eels, Mar 31 '20 at 19:38
that looks OK to this untrained eye. Have you tested -- what is null on the line throwing the exception? Have you gone through all the answers in the duplicate? Remember, only *you* have the complete code, and so only *you* can fully debug this thing — Hovercraft Full Of Eels, Mar 31 '20 at 22:17
I wrote that line 24 has npe problem `kaleciKayit.setOnClickListener(new View.OnClickListener() {` this line — Akinci, Apr 01 '20 at 12:14
OK, that's a start. Now you need to debug the problem as per the answers in the duplicate -- go through each answer and see if it applies. I'm afraid that these NPE's can only be debugged by the person with the code. All we can do is direct you to resources that can help you in the task. Good luck. — Hovercraft Full Of Eels, Apr 01 '20 at 12:51
thanks for help but why did you close my question? maybe someone else can help me? — Akinci, Apr 01 '20 at 13:08
Because *no one can help you*. You must debug this yourself as per the duplicate — Hovercraft Full Of Eels, Apr 01 '20 at 13:36
`Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference at com.easoft.aldimverdim.oyuncuAdlariActivity.onCreate(oyuncuAdlariActivity.java:27)` this is what I got in logcat and line 27 is `kaleciKayit.setOnClickListener(new OnClickListener() {` I am researching on google but nothing can help — Akinci, Apr 01 '20 at 14:04
I just copied original xml to v23 xml it makes difference? because I dont know why app has v23 xml — Akinci, Apr 01 '20 at 15:36

nullpointerexception error I know which line has error but how can I fix?

0 Answers0