How to show menu item in action bar?

I want the menu items to show on action bar. There is a lot of space on the ActionBar, but still they don't show up. Every item shown as three dots, why?

.java file

public class GalleryActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.gallery_layout); } public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.main_menu, menu); return true; } } 

.xml file

 <?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:MissionAndroid="http://schemas.android.com/tools"> <item android:id="@+id/facebookId" android:title="facebook" android:icon="@drawable/facebook" MissionAndroid:showAsAction="always"/> <item android:id="@+id/shareId" android:title="share" android:icon="@drawable/share" MissionAndroid:showAsAction="always"/> <item android:id="@+id/delete" android:title="delete" android:icon="@drawable/delete" MissionAndroid:showAsAction="always"/> <item android:id="@+id/searchId" android:title="search" android:icon="@drawable/search" MissionAndroid:showAsAction="ifRoom"/> </menu>