Usual_Or_FP.java

// variant A:
if (fromDateTimeMs != null) {
    where.and(timeColumn.goe(new Timestamp(fromDateTimeMs)));
}
if (tillDateTimeMs != null) {
    where.and(timeColumn.lt(new Timestamp(tillDateTimeMs)));
}

// variant B:
Stream.of(
        fromDateTimeMs == null ? null : timeColumn.goe(new Timestamp(fromDateTimeMs)),
        tillDateTimeMs == null ? null : timeColumn.lt(new Timestamp(tillDateTimeMs))
).filter(Objects::nonNull).reduce(BooleanExpression::and).ifPresent(where::and);