ISBNNumberExample.java

//import required classes and packages
import java.util.*;
import java.io.*;
import java.util.Scanner;

//create ISBNNumberExample class to check wether the given number is valid ISBN r not
 class ISBNNumberExample {
	 
	 static boolean checkISBNNumber(long number)
	 {
		 int sum = 0;
		int i , t , intNumber , dNumber;
		String strNumber;
		
		strNumber = ""+number;
		
		if(strNumber.length()!=10) {
			return false;
		}
		
		for (i=0; i < strNumber.length(); i++) {
			intNumber = Integer.parseInt(strNumber.substring(i,i+1));
			dNumber = i+1;
			t = dNumber*intNumber;
			sum = sum+t;
		}
//check wether the sum is divisible by 11 or not
		if((sum%11)==0) {
			return true;
		}
		return false;
	 }
//main() method start
	 public static void main (String [] args) {
		 long n1 , n2;
		 
		 try {
		//create BuffereReader class object to get input from user
			 InputStreamReader in = new InputStreamReader(System.in);
			 BufferedReader br = new BufferedReader(in);
		//show custom message
			 System.out.println("Enter first 10 digit ISBN number");
			//store user entered value into variable n1
			 n1 = Long.parseLong(br.readLine());
			//show custom message
			 System.out.println("Enter second 10 digit number");
			//store user entered value into variable n2
			 n2 = Long.parseLong(br.readLine());
		if (checkISBNNumber(n1))
			System.out.println(n1+"is a valid ISBn Numebr");
		else 
			System.out.println(n1+"is not a valid ISBN Number");
		if (checkISBNNumber(n2))
			System.out.println(n2+"is a valid ISBn Numebr");
		else 
			System.out.println(n2+"is not a valid ISBN Number");
			 
		 }catch(java.lang.Exception e) {
			 System.out.println("Error while reading the data.");
		 }
	 }
}