Hey, I’m trying to implement a ListView on Android, which will print the data

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Asked: May 18, 20262026-05-18T21:59:13+00:00 2026-05-18T21:59:13+00:00

Hey, I’m trying to implement a ListView on Android, which will print the data

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Hey, I’m trying to implement a ListView on Android, which will print the data retrieved from the SQLite Database. So I want to retrieve a lot of columns from the table and add this to a list, so I will print this list as a ListView.

For this I created a method that will select all the columns from the table in a separate class, and I will print the ListView in a ListActivity.

I want to retrieve 6 columns of the table, which is represented by the ids 2, 4, 5, 6, 7, 9.

But it shows a lot of errors:

12-24 19:19:04.066: ERROR/AndroidRuntime(22630): FATAL EXCEPTION: main
12-24 19:19:04.066: ERROR/AndroidRuntime(22630): java.lang.NullPointerException
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:355)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.AbsListView.obtainView(AbsListView.java:1418)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ListView.makeAndAddView(ListView.java:1745)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ListView.fillDown(ListView.java:670)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ListView.fillFromTop(ListView.java:727)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.ListView.layoutChildren(ListView.java:1598)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.AbsListView.onLayout(AbsListView.java:1248)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1254)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1130)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1047)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1254)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1130)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1047)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.View.layout(View.java:7175)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1140)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.os.Looper.loop(Looper.java:123)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at android.app.ActivityThread.main(ActivityThread.java:3647)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at java.lang.reflect.Method.invokeNative(Native Method)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at java.lang.reflect.Method.invoke(Method.java:507)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-24 19:19:04.066: ERROR/AndroidRuntime(22630):     at dalvik.system.NativeStart.main(Native Method)

Here is the code of the method that select the data.

public List<String> selectAll() {

    List<String> list1 = new ArrayList<String>();
    List<String> list2 = new ArrayList<String>();
    List<String> list3 = new ArrayList<String>();
    List<String> list4 = new ArrayList<String>();
    List<String> list5 = new ArrayList<String>();
    List<String> list6 = new ArrayList<String>();

    Cursor cursor = this.db.query(TABLE_NAME, null, null, null, null, null,
            "duration desc");

    if (cursor.moveToFirst()) {
        do {

            list1.add(cursor.getString(2));
            list2.add(cursor.getString(4));
            list3.add(cursor.getString(5));
            list4.add(cursor.getString(6));
            list5.add(cursor.getString(7));
            list6.add(cursor.getString(9));

            list1.addAll(list2);
            list1.addAll(list3);
            list1.addAll(list4);
            list1.addAll(list5);
            list1.addAll(list6);

        } while (cursor.moveToNext());
        Log.i(TAG, "After cursor.moveToNext()");
    }
    if (cursor != null && !cursor.isClosed()) {
        cursor.close();
    }
    Log.i(TAG, "Before selectAll returnment");
    return list1;
}

And here is the code of the ListActivity class:

public class RatedCalls extends ListActivity {

private static final String LOG_TAG = "RatedCallsActivity";
private CallDataHelper cdh;
StringBuilder sb = new StringBuilder();
OpenHelper openHelper = new OpenHelper(RatedCalls.this);

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    Log.i(LOG_TAG, "calling from onCreate()");

    cdh = new CallDataHelper(this);

    Log.i(LOG_TAG, "--->>> before calling the service");
    startService(new Intent(this, RatedCallsService.class));
    Log.i(LOG_TAG, "Service called.");
    Log.i(LOG_TAG, "--->>> after calling the service");
    fillList();

}

public void fillList() {

    List<String> ratedCalls = this.cdh.selectAll();

    setListAdapter(new ArrayAdapter<String>(this, R.layout.listitem,
            ratedCalls));

    ListView lv = getListView();
    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // When clicked, show a toast with the TextView text
            Toast.makeText(getApplicationContext(),
                    ((TextView) view).getText(), Toast.LENGTH_SHORT).show();
        }
    });
}
    }

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1 Answer

Editorial Team · Answer 1 · 2026-05-18T21:59:14+00:00

Editorial Team

2026-05-18T21:59:14+00:00Added an answer on May 18, 2026 at 9:59 pm

The problem was that in the database if the column value was empty, the cursor returned null, so, that was the JavaNullPointerException. So If there was no contact name to insert in the database, I inserted an empty string. That works!

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