Java - Convertir int a double

package practica.pkg3;

import java.util.Scanner;

public class ejercicio {

    public static void main(String[] args) {

        Scanner s = new Scanner(System.in);

        double nota;

        int x;

        System.out.println("Introduce tu nota");

        nota = s.nextDouble();

        int x = (int) nota;

        switch(x){

            case 0:

            case 1:

            case 2:

            case 3:

                System.out.println("Insuficiente");

                break;

            case 4:

            case 5:

                System.out.println("Regular");

                break;

            case 6:

                System.out.println("Bien");

                break;

            case 7:

            case 8:

                System.out.println("Notable");

                break;

            case 9:

            case 10:

                System.out.println("Sobresaliente");

                break

            default:

                System.out.println("Nota no válida");

        }

    }

}

int x = 1;

double nota = Double.parseDouble(String.valueOf(x));

System.out.println(nota);

1.0