NullPointerException on Activity's onCreate method. Have to add a view dynamically before setContentView()

Question

The below code results in a NullPointerException. The error is shown at the line linearLayout.addView(listView).

What's wrong?

public class SettingsActivity extends AppCompatActivity{
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ListView listView = new ListView(this);
    listView.setAdapter(new ArrayAdapter<String>(this,R.layout.settings_list_items_layout,R.id.settings_text_view_id,settingsItem));

    LinearLayout linearLayout = findViewById(R.id.settings_linear_layout);
    linearLayout.addView(listView);

    setContentView(linearLayout);

   }
}

The error code shown is below

05-10 11:58:37.920 5131-5131/com.example.malai_pt1882.economictimesdemo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.malai_pt1882.economictimesdemo, PID: 5131
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.malai_pt1882.economictimesdemo/com.example.malai_pt1882.economictimesdemo.SettingsActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.LinearLayout.addView(android.view.View)' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6494)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.LinearLayout.addView(android.view.View)' on a null object reference
    at com.example.malai_pt1882.economictimesdemo.SettingsActivity.onCreate(SettingsActivity.java:34)
    at android.app.Activity.performCreate(Activity.java:7009)
    at android.app.Activity.performCreate(Activity.java:7000)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6494) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

It shows the error in addView() method.