SearchView is null android

In Menu Layout :

<item
    android:id="@+id/action_search"
    android:icon="@drawable/ic_action_search"
    app:showAsAction="collapseActionView|always"
    android:title="@string/action_search"
    android:actionViewClass="android.support.v7.widget.SearchView"/>

use this :

<item
    android:id="@+id/action_search"
    android:icon="@drawable/ic_action_search"
    app:showAsAction="collapseActionView|always"
    android:title="@string/action_search"
    app:actionViewClass="android.support.v7.widget.SearchView"/>

So you need to use app instead of android in the menu item tag :

    app:actionViewClass="android.support.v7.widget.SearchView"