Add menu  in res/menu/main_activity_actions.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <!-- Search, should appear as action button -->
    <item android:id="@+id/action_search"
          android:icon="@drawable/ic_action_search"
          android:title="@string/action_search"
          android:showAsAction="ifRoom" />
    <!-- Settings, should always be in the overflow -->
    <item android:id="@+id/action_settings"
          android:title="@string/action_settings"
          android:showAsAction="never" />
</menu>

Use this override method

// This method will show menu in action bar
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu items for use in the action bar
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_activity_actions, menu);
    return super.onCreateOptionsMenu(menu);
}

 And now again use below override method

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle presses on the action bar items
    switch (item.getItemId()) {
        case R.id.action_search:// your code here       
            return true;
        case R.id.action_settings:// your code here       
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}