[JAVA] OffsetDateTime, LocalDateTime parameter format broken usingGet API

Description

I want send LocalDateTime parameter using get method.

DateTimeFormatter formater = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
LocalDateTime localDateTime = LocalDateTime.parse("2018-02-21'T'18:11:00.000Z", formatter);

but, swagger generate code like this.

public String parameterToString(Object param) {
        if (param == null) {
             return "";
        } else if (param instanceof Date) {
            return formatDatetime((Date) param);
        } else if (param instanceof Collection) {
            StringBuilder b = new StringBuilder();
            for (Object o : (Collection)param) {
                if (b.length() > 0) {
                    b.append(",");
                }
                b.append(String.valueOf(o));
            }
            return b.toString();
        } else {    //LocalDateTime and OffsetDateTIme task here!
            return String.valueOf(param);
        }
}

Expected : 2018-02-21'T'18:11:00.000Z
Actual : 2018-02-21'T'18:11

Swagger-codegen version

2.2.3

How can I catch instanceOf LocalDateTime and OffsetDateTime?

Start at the generated Java parameterToString(Object param) method and trace the template or generator entry point that produces it. Check how LocalDateTime and OffsetDateTime are serialized for GET parameters, then verify that the output preserves the expected timestamp format rather than truncating it.