Write a Program for left shift operator

a<< n or -a<<n

import java.io.*;
class MyFirstProg
{
 public static void main(String args[])
 {
  int i=31,x=1,sum=0,j;
  int bin[] = new int[32];
  int bin1[] = new int[32];
  Console con = System.console();
  System.out.print("Enter a Value");
  int num = Integer.parseInt(con.readLine());
  System.out.print("Enter a Shift");
  int b = Integer.parseInt(con.readLine());
  if(num>0)
  {
   // convert decimal to binary and print
   while(num!=0)
   {
    bin[i]=num%2;
    num=num/2;
    i--;
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin[i]);
   }
   System.out.println();
   
    // left shift and print
   
   for(i=31,j=31-b;j>=0;i--,j--)
   {
    bin1[j]=bin[i];
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin1[i]);
   }
   System.out.println();
   
    // convert binary to decimal
   
   for(i=31;i>=0;i--)
   {
    sum=sum+x*bin1[i];
    x=x*2;
   }
   System.out.println("Number after Shift"+sum);
  }
  else
  {
   // convert binary to decimal and print
   
   num=num*(-1);
   while(num!=0)
   {
    bin[i]=num%2;
    num=num/2;
    i--;
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin[i]);
   }
   System.out.println();
   
    // 1's and 2's compliment and print
   
   for(i=31;i>=0;i--)
   {
    if(bin[i]==0)
     bin[i]=1;
    else
     bin[i]=0;
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin[i]);
   }
   System.out.println();
   for(i=31;i>=0;i--)
   {
    if(bin[i]==1)
     bin[i]=0;
    else
    {
     bin[i]=1;
     break;
    }
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin[i]);
   }
   System.out.println();
   
   // left shift and print
   
   for(i=31,j=31-b;j>=0;i--,j--)
   {
    bin1[j]=bin[i];
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin1[i]);
   }
   System.out.println();
   
    // 1's and 2's compliment and print
   
   for(i=31;i>0;i--)
   {
    if(bin1[i]==0)
     bin1[i]=1;
    else
     bin1[i]=0;
   }
   i=31;
   while(i>=0)
   {
    if(bin1[i]==1)
     bin1[i]=0;
    else
    {
     bin1[i]=1;
     break;
    }
    i--;
   }
   for(i=31;i>=0;i--)
   {
    System.out.print(bin1[i]);
   }
   System.out.println();
   
    // binary to decimal convert
   
   for(i=31;i>0;i--)
   {
    sum=sum+x*bin1[i];
    x=x*2;
   }
   sum=sum*(-1);
   System.out.println("Number after Shift"+sum);
  }
 }
}