Transform Optional String and return Date in Java 8? - java-8

Question

I am currently parsing a nullable String to a Date. I try to use Optional to avoid using if statement. Here is what I have written so far :
Client client = new Client();
Optional.ofNullable(methodThatMayReturnStringOrNull())
.ifPresent((s) -> {
try {
client.setBirthDate(DateUtils.parseDate(
StringUtils.substring(s, 0, 10),
new String[]{"yyyy-MM-dd"}));
} catch (ParseException e) {
throw new TechnicalException("error.parsing.date", e);
}
});
Is it possible to transform this lambda so I can make it a method similar to the following but java 8 style?
private Date parse(String complexString) {
Date birthDate = null;
if (complexString != null) {
try {
birthDate = DateUtils.parseDate(
StringUtils.substring(complexString, 0, 10),
new String[]{"yyyy-MM-dd"});
} catch (final ParseException e) {
throw new TechnicalException("error.parsing.date", e);
}
}
return birthDate;
}

Answer 1

Not sure how far you want to go, but you can start with
Optional<Date> date = Optional.ofNullable(methodThatMayReturnStringOrNull())
.map((s) -> {
try {
return DateUtils.parseDate(
StringUtils.substring(s, 0, 10),
new String[]{"yyyy-MM-dd"}));
} catch (ParseException e) {
throw new TechnicalException("error.parsing.date", e);
}
});
You might also consider using flatMap instead of map and returning empty optional instead of throwing exception on error - depends on how you want to progress you flow.
On completely unrelated note, get rid of Date and use either joda or new java time classes ;)