Null Pointer Exception on Edit Text Android

Question

I'm writing a program to save user input from the edit text and inserting the text into a listview. I keep getting this null exception even though I've declared the Edit Text already.

public class AddEditAlbum extends AppCompatActivity {

/**
 * These keys are to send back and forth information between the bundles and intents
 */
public static final String ALBUM_INDEX = "albumIndex";
public static final String ALBUM_NAME = "albumName";
EditText input;
Button save, cancel;
int albumIndex;

@Override
protected void onCreate(Bundle savedInstanceState) {

    save = (Button) findViewById(R.id.save);
    cancel = (Button) findViewById(R.id.cancel);
    input = (EditText) findViewById(R.id.add);

    // see if info was passed in to populate field
    Bundle bundle = getIntent().getExtras();
    if (bundle != null) {
        albumIndex = bundle.getInt(ALBUM_INDEX);
        input.setText(bundle.getString(ALBUM_NAME));
    }

    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_album);
}

public void Cancel(View view) {
    setResult(RESULT_CANCELED);
    finish();   //Returns to previous page on call stack
}

public void addAlbum(View view){

    String name = input.getText().toString();   //Fix this, goes to null pointer

    //Checks to see if input is null and returns
    if(name == null || name.length()==0){
        Toast.makeText(AddEditAlbum.this, "Enter valid album name", Toast.LENGTH_SHORT).show();
        Bundle bundle = new Bundle();
        bundle.putString(AlbumDialog.MESSAGE_KEY, "Album Name Required");
        DialogFragment newFragment = new AlbumDialog();
        newFragment.setArguments(bundle);
        newFragment.show(getFragmentManager(), "badfields");
        return;
    }
    //Toast.makeText(AddEditAlbum.this, "Enter valid album name", Toast.LENGTH_SHORT).show();
    Bundle bundle = new Bundle();
    bundle.putInt(ALBUM_INDEX, albumIndex);
    bundle.putString(ALBUM_NAME, name);

    // send back to caller
    Intent intent = new Intent();
    intent.putExtras(bundle);
    setResult(RESULT_OK,intent);
    finish();
}

}

public class MainActivity extends AppCompatActivity {

ListView listView;
private ArrayList<Album> albums;
public static final int EDIT_ALBUM_CODE = 1;
public static final int ADD_ALBUM_CODE = 2;

@Override
protected void onCreate(Bundle savedInstanceState) {

    listView = (ListView) findViewById(R.id.album_list);

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

public void Create(View view){
    Intent intent = new Intent(this, AddEditAlbum.class);
    startActivityForResult(intent, ADD_ALBUM_CODE);
}

protected void onActivityResult(int requestCode, int resultCode, Intent intent) {

    if (resultCode != RESULT_OK) {
        return;
    }

    Bundle bundle = intent.getExtras();
    if (bundle == null) {
        return;
    }

    // gather all info passed back by launched activity
    String name = bundle.getString(AddEditAlbum.ALBUM_NAME);
    int index = bundle.getInt(AddEditAlbum.ALBUM_INDEX);

    if (requestCode == EDIT_ALBUM_CODE){
        Album album = albums.get(index);
        album.albumName = name;
    }
    else if (requestCode == ADD_ALBUM_CODE){
        ArrayList<Photo> photos = new ArrayList<>();
        albums.add(new Album(name, photos));
    }

    // redo Adapter since source content has changed
    //listView.setAdapter(new ArrayAdapter<Album>(this, album, albums));

}

So this is the full error I'm getting,

FATAL EXCEPTION: main
                                                                             Process: com.example.mustu.androidphotos31, PID: 9965
                                                                             java.lang.IllegalStateException: Could not execute method for android:onClick
                                                                                 at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
                                                                                 at android.view.View.performClick(View.java:5610)
                                                                                 at android.view.View$PerformClick.run(View.java:22265)
                                                                                 at android.os.Handler.handleCallback(Handler.java:751)
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                 at android.os.Looper.loop(Looper.java:154)
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                                                                              Caused by: java.lang.reflect.InvocationTargetException
                                                                                 at java.lang.reflect.Method.invoke(Native Method)
                                                                                 at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
                                                                                 at android.view.View.performClick(View.java:5610) 
                                                                                 at android.view.View$PerformClick.run(View.java:22265) 
                                                                                 at android.os.Handler.handleCallback(Handler.java:751) 
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:95) 
                                                                                 at android.os.Looper.loop(Looper.java:154) 
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6077) 
                                                                                 at java.lang.reflect.Method.invoke(Native Method) 
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 
                                                                              Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference
                                                                                 at com.example.mustu.androidphotos31.AddEditAlbum.addAlbum(AddEditAlbum.java:54)
                                                                                 at java.lang.reflect.Method.invoke(Native Method) 
                                                                                 at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
                                                                                 at android.view.View.performClick(View.java:5610) 
                                                                                 at android.view.View$PerformClick.run(View.java:22265) 
                                                                                 at android.os.Handler.handleCallback(Handler.java:751) 
                                                                                 at android.os.Handler.dispatchMessage(Handler.java:95) 
                                                                                 at android.os.Looper.loop(Looper.java:154) 
                                                                                 at android.app.ActivityThread.main(ActivityThread.java:6077) 
                                                                                 at java.lang.reflect.Method.invoke(Native Method) 
                                                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
                                                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Which line is this `at com.example.mustu.androidphotos31.AddEditAlbum.addAlbum(AddEditAlbum.java:54)` — Al Lelopath, Apr 26 '17 at 13:26
@AlLelopath OP mentions this in the code, it's the line ``String name = input.getText().toString()``, which is the first line in the ``addAlbum()`` method. — f1sh, Apr 26 '17 at 13:27
Is it `input` that is `null`, or is it `input.getText()` that is `null`? — mous, Apr 26 '17 at 13:29
@mous input is null. The NPE is caused by the attempt to call getText on a null object — Tim, Apr 26 '17 at 13:30

score 8 · Accepted Answer · answered Apr 26 '17 at 13:27

8

super.onCreate(savedInstanceState);
setContentView(R.layout.add_album);

This has to be executed first, otherwise the contentView is not set and findViewById will not find anything, resulting in the EditText being null.

answered Apr 26 '17 at 13:27

Tim

41,901
18
127
145

Thank you very much it worked! – M. Hussain Apr 27 '17 at 14:20

Akshay · Answer 2 · 2017-04-26T13:34:17.663

0

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.album_list);

}

Also You are calling your listview before onCreate method thus giving you a NPE

edited Apr 26 '17 at 13:34

answered Apr 26 '17 at 13:31

Akshay

1,161
1
12
33

I already said this 6 mins ago. Repeating it is not useful – Tim Apr 26 '17 at 13:33
I was typing the ans and then saw that:( – Akshay Apr 26 '17 at 13:35

score 0 · Answer 3 · answered Apr 26 '17 at 13:32

update your onCreate() like this.
we should call setContentView(R.layout.your_layout) for passing the layout to the java class, then only it's views can be used.. failing to do so, will lead to NPE. 

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_album);

    save = (Button) findViewById(R.id.save);
    cancel = (Button) findViewById(R.id.cancel);
    input = (EditText) findViewById(R.id.add);

    // see if info was passed in to populate field
    Bundle bundle = getIntent().getExtras();
    if (bundle != null) {
        albumIndex = bundle.getInt(ALBUM_INDEX);
        input.setText(bundle.getString(ALBUM_NAME));
    }


}

I already said this 6 mins ago. Repeating it is not useful – Tim Apr 26 '17 at 13:33 — Tim, Apr 26 '17 at 13:33
@TimCastelijns oops.. I missed that. :) – Ankit Purwar Apr 26 '17 at 13:34 — Ankit Purwar, Apr 26 '17 at 13:34

Null Pointer Exception on Edit Text Android

3 Answers3