Internet checksum program java

import java.util.*; 

 class InternetChecksum

 {

 public static void main (String args[])

{
  Scanner scan = new Scanner (System.in);

 System.out.println("Enter the string input:"); 

 String input = scan.next();

 int checksum = generateChecksum(input); 

 System.out.println("The checksum generated is "+Integer.toHexString(checksum));
  System.out.println("Enter the data to be sent:"); 

 input = scan.next(); 

 System.out.println("Enter the checksum to be sent:"); 

 checksum = Integer.parseInt((scan.next()),16); 

 receive(input,checksum);

 } 

 static int generateChecksum(String s) 

{

 String hex_value = new String();

 int x,i,checksum=0; 

 for(i=0; i <s.length()-2; i=i+2)

{
   x = (int)(s.charAt(i));

 hex_value = Integer.toHexString(x); 

 x = (int)(s.charAt(i+1)); 

 hex_value = hex_value + Integer.toHexString(x);
   System.out.println(s.charAt(i)+""+s.charAt(i+1)+":"+hex_value); 

 x=Integer.parseInt(hex_value,16); 

 checksum+=x;

 } 

 if(s.length()%2==0)

{
   x = (int)(s.charAt(i)); 

 hex_value = Integer.toHexString(x); 

 x = (int)(s.charAt(i+1)); 

 hex_value = hex_value + Integer.toHexString(x);
   System.out.println(s.charAt(i)+""+s.charAt(i+1)+":"+hex_value); 

 x=Integer.parseInt(hex_value,16);
   checksum+=x; 

 } 

 else

{
   x =(int)(s.charAt(i)); 

 hex_value= "00" + Integer.toHexString(x); 

 x=Integer.parseInt(hex_value,16); 

 System.out.println(s.charAt(i) + " : " + hex_value);

 } 

 checksum+=x;

 hex_value=Integer.toHexString(checksum); 

 if(hex_value.length()>4)

{
   int carry = Integer.parseInt(""+hex_value.charAt(0),16); 

 hex_value=hex_value.substring(1,5); 

 checksum=Integer.parseInt(hex_value,16); 

 checksum+=carry; 

 } 

 checksum = generateComplement(checksum);

 return checksum;

 }

 static void receive (String s, int checksum)

{ 

 int generated_Checksum = generateChecksum(s); 

 generated_Checksum = generateComplement(generated_Checksum); 

 int syndrome = generated_Checksum+checksum; 

 syndrome = generateComplement(syndrome); 

 System.out.println("Syndrome = " + Integer.toHexString(syndrome)); 

 if(syndrome == 0) 

{
   System.out.println("Data is received without error.");

 }

 else 

{
   System.out.println("There is an error in the received data.");

 }

 } 

 static int generateComplement (int checksum)

{
  checksum = Integer.parseInt("FFFF",16) - checksum;
  return checksum;
 } 

}

Happy coding!! 

Enjoy!