box_edittext_otp.xml

<EditText
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_weight="1"
          android:layout_marginLeft="0dp"
          android:id="@+id/edt1"
          style="@style/edt_otp"
/>

<!--style-->
 <style name="edt_otp">
        <item name="android:background">@drawable/bg_textview_box</item>
        <item name="android:padding">@dimen/margin8dp</item>
        <item name="android:hint">-</item>
        <item name="android:gravity">center</item>
        <item name="android:layout_marginLeft">10dp</item>
        <item name="android:textColorHint">#FF303030</item>
        <item name="android:maxLines">1</item>
        <item name="android:maxLength">1</item>
        <item name="android:inputType">number</item>
        <item name="android:imeOptions">actionNext</item>
        <item name="android:selectAllOnFocus">true</item>
    </style>

<!--background-->
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_focused="true">
        <shape>
            <stroke android:width="1dp" android:color="@color/colorAccent" />
        </shape>
    </item>
    <item>
        <shape>
            <stroke android:width="1dp" android:color="#dddddd" />
        </shape>
    </item>
</selector>