Hexadecimal to Binary Error Java -

i trying convert hexadecimal binary problem result ignoring zeroes should on left hand side crucial me.

my code:

public static void main(string[] args) {     // todo auto-generated method stub     scanner scan;     int num;      system.out.println("hexadecimal binary");     scan = new scanner(system.in);      system.out.println("\nenter number :");     num = integer.parseint(scan.nextline(), 16);      string binary = integer.tobinarystring(num);      system.out.println("binary value : " + binary);  } 

output : when giving input 0000000000001a000d00 should output as

00000000000000000000000000000000000000000000000000011010000000000000110100000000 

but instead 11010000000000000110100000000 leaving initial zeroes.

how should exact number. in advance.

you can try solution link (how 0-padded binary representation of integer in java?) provided @johnh, combined calculating length of binary representation of hex number. each hexadecimal digit requires 4 binary digits represent:

public static void main( string[] args ) {     scanner scan;     int num;      system.out.println("hexadecimal binary");     scan = new scanner(system.in);      system.out.println("\nenter number :");     string input = scan.nextline().trim();     num = integer.parseint(input, 16);      int paddedlength = input.length() * 4;     string binary = string.format("%"+ paddedlength +"s", integer.tobinarystring(num)).replace(' ', '0');     system.out.println("binary value : " + binary); } 

it's not perfect, should trick.