how to validate isbn numbers code java code example
Example: validate isbn number java
public boolean validateIsbn10( String isbn )
{
if ( isbn == null )
{
return false;
}
isbn = isbn.replaceAll( "-", "" );
if ( isbn.length() != 10 )
{
return false;
}
try
{
int tot = 0;
for ( int i = 0; i < 9; i++ )
{
int digit = Integer.parseInt( isbn.substring( i, i + 1 ) );
tot += ((10 - i) * digit);
}
String checksum = Integer.toString( (11 - (tot % 11)) % 11 );
if ( "10".equals( checksum ) )
{
checksum = "X";
}
return checksum.equals( isbn.substring( 9 ) );
}
catch ( NumberFormatException nfe )
{
return false;
}
}