Provide meaningful exception messages

[eximius313]

This code:

Iban build = new Iban.Builder()
        .countryCode(CountryCode.PL)
        .bankCode("22876")
        .accountNumber("63810519014")
        .build();
    System.out.println(build);

throws following exception:

Exception in thread "main" org.iban4j.IbanFormatException: [76nu] must contain only digits.
	at org.iban4j.IbanUtil.validateBbanEntryCharacterType(IbanUtil.java:409)
	at org.iban4j.IbanUtil.validateBbanEntries(IbanUtil.java:379)
	at org.iban4j.IbanUtil.validate(IbanUtil.java:80)
	at org.iban4j.Iban$Builder.build(Iban.java:365)
	at org.iban4j.Iban$Builder.build(Iban.java:337)

And what is even more weird, this code:

    Iban randomIban = Iban.random(CountryCode.PL);
    Iban build = new Iban.Builder()
        .countryCode(CountryCode.PL)
        .bankCode(randomIban.getBankCode())
        .accountNumber(randomIban.getAccountNumber())
        .build();

throws following exception:

Exception in thread "main" org.iban4j.IbanFormatException: [270nullnull2789991694524099] length is 27, expected BBAN length is: 24
	at org.iban4j.IbanUtil.validateBbanLength(IbanUtil.java:362)
	at org.iban4j.IbanUtil.validate(IbanUtil.java:79)
	at org.iban4j.Iban$Builder.build(Iban.java:365)
	at org.iban4j.Iban$Builder.build(Iban.java:337)

what's wrong?

[arturmkrtchyan]

Polish IBAN's have the following structure:

.countryCode(CountryCode.PL)
.bankCode("109")
.branchCode("0101")
.accountNumber("0000071219812874")
.nationalCheckDigit("4")

[eximius313]

Could I ask then for more meaningful error messages in both cases and treat this issue as a Improvement Request?
Something like:
"branchCode" is required for requested CountryCode: XY
"nationalCheckDigit" is required for requested CountryCode: XY

[arturmkrtchyan]

Absolutely!
Lately I have not been actively adding feature requests, but going forward I'm planning to dedicate some time to it.

[eximius313]

Thank you so much!
I spend a lot of time debugging why [76nu] must contain only digits despite I provided only digits :)