import java.util.*;
import javax.ejb.*;

public class ValidateEJB implements SessionBean {


   String cardNo;
   public void ejbCreate(String CardNo) throws CreateException 
      {

	if( CardNo.equals(""))
	{
	  throw new CreateException("Null person or card number not allowed.");
	}
        else 
		cardNo=CardNo;
	 
      }


public static char leftchar(String CardNo) 
{
 return(CardNo.charAt(0));
}


public static char rightchar(String CardNo) 
{
return(CardNo.charAt(CardNo.length() - 1));
}

public static int chtoint(char ch) 
{
        if (ch == '0') return(0);
        if (ch == '1') return(1);
        if (ch == '2') return(2);
        if (ch == '3') return(3);
        if (ch == '4') return(4);
        if (ch == '5') return(5);
        if (ch == '6') return(6);
        if (ch == '7') return(7);
        if (ch == '8') return(8);
        if (ch == '9') return(9);
        return(0);
    }

	
     public int validate(String CardNo)
	{ 

  	int i;
   	int total = 0;
	String tempMult = "";

   for (i = CardNo.length(); i >= 2; i -= 2) 
   {
    total = total + chtoint(CardNo.charAt(i - 1));
    tempMult = "" + (chtoint(CardNo.charAt(i - 2)) * 2);
    total = total + chtoint(leftchar(tempMult));
    if (tempMult.length() > 1) 
    {
    total = total + chtoint(rightchar(tempMult));
    }
   }
   
  if (CardNo.length() % 2 == 1) 
  {
  total = total + chtoint(leftchar(CardNo));
  }
        
  if (total % 10 == 0)
  {
  return 0;
  }
  else 
  {
  // System.out.println("Invalid card number");  
   return 1;
  }
}
   public ValidateEJB() {}
   public void ejbRemove() {}
   public void ejbActivate() {}
   public void ejbPassivate() {}
   public void setSessionContext(SessionContext sc) {}

}