Let's Shift Bits

import java.util.Scanner;
import java.math.BigInteger; // import BigInteger method
public class ShiftBits {
  public static void main (String [] args) {
    Scanner in = new Scanner(System.in);
    System.out.print("Enter number of bits: ");
    int bi = in.nextInt();
    int [] a = new int [bi]; // create array to keep binary number that you have to input
    for (int q = 0 ; q < a.length ; q++)
    {
      System.out.printf("Insert your %d position bit", q);
      int d = in.nextInt();
      a[q] = d; // add bit to the array
    }
    String b = getBi(a); // call method
    printRe(b); // call method to print
    System.out.println("Do you want to shift?\nIf yes and shift right say 1\nIf no say 0\nIf yes and shift left say -1"); // ask
    int u = in.nextInt();
    switch (u) { // use this instead of IF
      case 0: System.out.print("Thank you for playing");
              break; // if you forget to write this all of the case will be executed
      case 1: System.out.print("What times you want to shift?: ");
              int v = in.nextInt();
              b = shiftR(b, v);
              printRe(b);
              break;
      case -1: System.out.print("What times you want to shift?: ");
               int k = in.nextInt();
               b = shiftL(b, k);
               printRe(b);
               break;
    }
  }
  public static String getBi(int[] l) {
    String h = "";
    for (int q = 0 ; q < l.length ; q++)
    {
      h = h + l[q];
    }
    return h;
  }
  public static String printRe(String n) {
    System.out.printf("Your Binary is: %s\n", n);
    int e = Integer.parseInt(n, 2); // change to decimal
    System.out.printf("Your Decimal value is: %d\n", e);
    String r = new BigInteger(n, 2).toString(16).toUpperCase(); // change to Hexadecimal and change to uppercase
    System.out.printf("Your Hexacimal value is: %s\n", r);
    return n;
  }
  public static String shiftR(String i, int d) {
    String x = i;
    for (int q = 0 ; q < d ; q++)
    {
      x = x + 0;
    }
    return x;
  }
  public static String shiftL(String i, int d) {
    String z = i;
    for (int q = 0 ; q < d ; q++)
    {
      z = 0 + z;
    }
    return z;
  }
}