android custom searchView rounded corners

Just give padding = corner radius,because corners are hidden by Actual SearchView Background will set it to back ,so padding makes the trick

drawable/bg_white_rounded.xml:

  <?xml version="1.0" encoding="utf-8"?>
    <shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#ffffff"/>
    <corners android:radius="8dp"/>
    <padding android:left="8dp"
        android:bottom="8dp"
        android:right="8dp"
        android:top="8dp"/>
    </shape>

While rajan ks (Thanks!) answer works, it doesn't resemble the design mockup a 100% (the padding naturally increases the SearchView's size while not increasing the contained EditText's size).

The solution I found is this: In the MainActivity.java, change search_edit_frame, search_plate and search_bar:

    int searchFrameId = searchView.getContext().getResources().getIdentifier("android:id/search_edit_frame", null, null);
    View searchFrame = searchView.findViewById(searchFrameId);
    searchFrame.setBackgroundResource(R.drawable.bg_white_rounded);

    int searchPlateId = searchView.getContext().getResources().getIdentifier("android:id/search_plate", null, null);
    View searchPlate = findViewById(searchPlateId);
    searchPlate.setBackgroundResource(R.drawable.bg_white_rounded);

    int searchBarId = searchView.getContext().getResources().getIdentifier("android:id/search_bar", null, null);
    View searchBar = findViewById(searchBarId);
    searchBar.setBackgroundResource(R.drawable.bg_white_rounded);

That results in the SearchView looking exactly like the mockup.