simple_data_binding_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>
        <variable name="userName" type="ak.com.apps.android.databinding.model.UserName" />
    </data>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:padding="20dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text='@{userName.firstName}' />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text='@{userName.middleName}' />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text='@{userName.lastName}' />

    </LinearLayout>

</layout>