Java Coding Problems

230. Throwing NoSuchElementException

Sometimes, if Optional is empty, we want to throw an exception (for example, NoSuchElementException). The clumsy solution to this problem is listed as follows:

// Avoidpublic String findStatus() {  Optional<String> status = ...; // this is prone to be empty  if (status.isPresent()) {    return status.get();  } else {    throw new NoSuchElementException("Status cannot be found");  }}

But a much more elegant solution will rely on the Optional.orElseThrow() method. The signature of this method, orElseThrow(Supplier<? extends X> exceptionSupplier), allows us to give the exception as follows (if the value is present then orElseThrow() will return it):

// Preferpublic String findStatus() { Optional<String> status = ...; ...