You don’t need to programmatically handle the default value of ListPreferences. You can do this in xml setting file. Below is an example
<string-array name="opts">
<item>red</item>
<item>green</item>
<item>blue</item>
</string-array>
<string-array name="opts_values">
<item>1</item>
<item>2</item>
<item>3</item>
</string-array>
…
<ListPreference
android:title="Colour select"
android:summary="Select your favourite"
android:key="colour"
android:entries="@array/opts"
android:entryValues="@array/opts_values"
android:defaultValue="2" />
here I selected 2 as a default value. Remember defaultvalue will be opts_values element.