How to parse and format an integer with zero decimal places in GWT? - gwt

Question

Using GWT NumberFormat, I need to have a decimal format that basically accepts no decimal point character and zero decimal places. For example, 123 should be valid but 123.4 and 123.9 should be rejected. Also, rounding of decimal values into nearest integer is not an option.
I thought the following would work, but it does not:
double val = NumberFormat.getFormat("#0").parse(str);
I definitely need it to support GWT i18n formatting, such as "," separators for large numbers. The input "str" is for example the argument coming to a Parser.parse(text) method, similar to the one in IntegerParser. IntegerParser does not validate zero decimal places properly and only rounds the value rather than rejecting numbers with decimal point.
Any ideas?

Answer 1

Use IntegerParser.
It uses the following method under the covers:
(int) Math.rint(NumberFormat.getDecimalFormat().parse(object.toString()));
UPDATE:
Also, you can use LongBox instead of TextBox.

Answer 2

The way I finally solved my problem was by explicitly looking for decimal separator in the input string before trying to parse it using NumberFormat. Here is the code:
final String DECIMAL_SEPARATOR =
LocaleInfo.getCurrentLocale().getNumberConstants().decimalSeparator();
if (str.contains(DECIMAL_SEPARATOR))
throw new ParseException("Invalid integer value (" + str + ")", 0);
return (int) Math.rint(NumberFormat.getDecimalFormat().parse(str));
I am still interested in finding a better way to do it using NumberFormat.