Cannot do null check on date in input field

Question

Java:

try {
    if (requestModel.getDateTo() != null || !(requestModel.getDateTo().isEmpty())) {
        formatter = new SimpleDateFormat("dd/MM/yyyy");
        Date dateTo = formatter.parse(requestModel.getDateTo());
        requestDOOb.setDateTo(dateTo);
    } else {
        requestDOOb.setDateTo(dateFrom);
    }
}
catch (ParseException e) {
    e.printStackTrace();
    return "request";
}

Exception:

java.text.ParseException: Unparseable date: "" at requestDOOb.setDateTo(dateFrom);

What should I actually be checking for in terms of the null pointer? The two conditions I provided do not seem to satisfy the exception requirement.

Answer 1

Your logic is incorrect. Use "&&" instead of "||".

Answer 2

if (requestModel.getDateTo() != null || !(requestModel.getDateTo().isEmpty()))

You have to use a && (and) instead of || (or).

You currently check if date is not null OR if it not empty.

So for an empty string you get (true || false) which is true and therefor it tries to parse the empty date.

Answer 3

Here:

if (requestModel.getDateTo() != null || !requestModel.getDateTo().isEmpty())

This will always evaluate both expressions.

You want to use && instead; to have that implicit guarantee that the first expression evaluated to true before making the second test.

|| has to evaluate both expressions (when the first one is false ); whereas && will not evaluate the second expression when the first one is false .