Converting binary string to a hexadecimal string JAVA

Question

I want to convert my binary(which is in string) to hexadecimal string also, this is just a program fragment since this program is just a part of another bigger program:

Answer 1

 import java.util.*;
 public class BinaryToHexadecimal
 {
      public static void main()
      {
         Scanner sc=new Scanner(System.in);
         System.out.println("enter the binary number");
         double s=sc.nextDouble();
         int c=0;
         long s1=0;
         String z="";
         while(s>0)
         {
           s1=s1+(long)(Math.pow(2,c)*(long)(s%10));
           s=(long)s/10;
           c++;
         }
         while(s1>0)
         {
           long j=s1%16;
           if(j==10)
           {
              z="A"+z;
           }
           else if(j==11)
           {
              z="B"+z;
           }
           else if(j==12)
           {
              z="C"+z;
           }
           else if(j==13)
           {
              z="D"+z;
           }
           else if(j==14)
           {
              z="E"+z;
           }
           else if(j==15)
           {
              z="F"+z;
           }
           else
           {
              z=j+z;
           }
           s1=s1/16;
      }
    System.out.println("The respective Hexadecimal number is : "+z);
   }
 }