android.support.v7.app.ActionBarActivity is deprecated
The line across ActionBarActivity means that it has been deprecated. Its just another way of denoting it. You should now use AppCompatActivity instead starting with version 22.1.0.
You can read more here.
Use
android.support.v7.app.AppCompatActivity
instead of
android.support.v7.app.ActionBarActivity
(DEPRECATED)
and extends AppCompatActivity
public myClass extends AppCompatActivity{
...
...
if you have the message:
cannot resolve symbol AppCompatActivity
You have to update to the last support library in your Android SDK Manager