How to use

getMessage

method

in

org.apache.commons.validator.routines.checkdigit.CheckDigitException

/**
 * Convert an ISBN-10 code to an ISBN-13 code.
 * <p>
 * This method requires a valid ISBN-10 with NO formatting
 * characters.
 *
 * @param isbn10 The ISBN-10 code to convert
 * @return A converted ISBN-13 code or <code>null</code>
 * if the ISBN-10 code is not valid
 */
public String convertToISBN13(String isbn10) {
  if (isbn10 == null) {
    return null;
  }
  String input = isbn10.trim();
  if (input.length() != ISBN_10_LEN) {
    throw new IllegalArgumentException("Invalid length " + input.length() + " for '" + input + "'");
  }
  // Calculate the new ISBN-13 code (drop the original checkdigit)
  String isbn13 = "978" + input.substring(0, ISBN_10_LEN - 1);
  try {
    String checkDigit = isbn13Validator.getCheckDigit().calculate(isbn13);
    isbn13 += checkDigit;
    return isbn13;
  } catch (CheckDigitException e) {
    throw new IllegalArgumentException("Check digit error for '" + input + "' - " + e.getMessage());
  }
}

  return ean13;
} catch (CheckDigitException e) { // Should not happen
  throw new IllegalArgumentException("Check digit error for '" + ean13 + "' - " + e.getMessage());

assertTrue("Invalid Character[" +i +"]=" +  e.getMessage(), e.getMessage().startsWith("Invalid "));

/**
 * Convert an ISBN-10 code to an ISBN-13 code.
 * <p>
 * This method requires a valid ISBN-10 with NO formatting
 * characters.
 *
 * @param isbn10 The ISBN-10 code to convert
 * @return A converted ISBN-13 code or <code>null</code>
 * if the ISBN-10 code is not valid
 */
public String convertToISBN13(String isbn10) {
  if (isbn10 == null) {
    return null;
  }
  String input = isbn10.trim();
  if (input.length() != ISBN_10_LEN) {
    throw new IllegalArgumentException("Invalid length " + input.length() + " for '" + input + "'");
  }
  // Calculate the new ISBN-13 code (drop the original checkdigit)
  String isbn13 = "978" + input.substring(0, ISBN_10_LEN - 1);
  try {
    String checkDigit = isbn13Validator.getCheckDigit().calculate(isbn13);
    isbn13 += checkDigit;
    return isbn13;
  } catch (CheckDigitException e) {
    throw new IllegalArgumentException("Check digit error for '" + input + "' - " + e.getMessage());
  }
}

  return ean13;
} catch (CheckDigitException e) { // Should not happen
  throw new IllegalArgumentException("Check digit error for '" + ean13 + "' - " + e.getMessage());