title: NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.RelativeLayout.findViewById(int)' on a null object reference
body: <p>I am trying to put a notification counter inside the action bar and it gives me this error inside the <code>onCreateOptionsMenu</code> method:</p>
  
  <pre><code>java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.RelativeLayout.findViewById(int)' on a null object reference
          at ro.oce.store.MainActivity.onCreateOptionsMenu(MainActivity.java:112)
          at android.app.Activity.onCreatePanelMenu(Activity.java:2823)
          at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:262)
          at android.support.v7.internal.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:85)
          at android.support.v7.app.AppCompatDelegateImplBase$AppCompatWindowCallbackBase.onCreatePanelMenu(AppCompatDelegateImplBase.java:241)
          at android.support.v7.internal.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:85)
          at android.support.v7.internal.app.ToolbarActionBar.populateOptionsMenu(ToolbarActionBar.java:448)
          at android.support.v7.internal.app.ToolbarActionBar$1.run(ToolbarActionBar.java:65)
          at android.os.Handler.handleCallback(Handler.java:739)
          at android.os.Handler.dispatchMessage(Handler.java:95)
          at android.os.Looper.loop(Looper.java:135)
          at android.app.ActivityThread.main(ActivityThread.java:5257)
          at java.lang.reflect.Method.invoke(Native Method)
          at java.lang.reflect.Method.invoke(Method.java:372)
          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
  </code></pre>
  
  <p>Here is the code:</p>
  
  <pre><code> public boolean onCreateOptionsMenu(Menu menu) {
      // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.menu_main, menu);
  
      RelativeLayout badgeLayout = (RelativeLayout) menu.findItem(R.id.shopping_cart).getActionView();
      TextView tv = (TextView) badgeLayout.findViewById(R.id.actionbar_notifcation_textview);
      tv.setText("12");
      return true;
  }
  </code></pre>
  
  <p>Before I added the last 3 lines of code, my application didn't generate any errors. Can somebody please help me?</p>