Ripple effect in android Lollipop

In this below, I have two example about ripple effect . it begin use from Android Lollipop 5.0: 

1.

ripple.xml

<?xml version="1.0" encoding="utf-8"?>
<ripple android:color="@color/COLOR_WHILE_PRESSING" xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:drawable="@drawable/background"></item>
</ripple>

background.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
 <solid android:color="@color/BACKGROUND_COLOR" />
 <corners android:radius="6dp" />
</shape>

Add two file drawable forder and try to view.

2.The same

<Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:background="@drawable/ripple"

    />

Where the ripple.xml is:

<ripple xmlns:android="http://schemas.android.com/apk/res/android" 
                      android:color="?android:colorControlHighlight">
        <item android:id="@android:id/mask">
            <shape android:shape="oval">
                <solid android:color="?android:colorAccent" />
            </shape>
        </item>
 </ripple>

Thanks