In Java, the Optional object is a container object which may or may not contain a value. The Optional class is present in the java.util package.
Note: You can read more about the
Optionalclass here.
ofNullable() method of the Optional class?The ofNullable() method is used to get an instance of the Optional class with a specified value.
If the value is null, then an empty Optional object is returned.
public static <T> Optional<T> ofNullable(T value)
This method takes a value that will be present in the Optional object.
This method returns an Optional object with the specified value. If the argument value is null, then an empty Optional object is returned.
The below code shows how to use the ofNullable() method:
import java.util.Optional;class OptionalOfNullableExample {public static void main(String[] args) {Optional<Integer> optional1 = Optional.ofNullable(1);System.out.println("Optional1: " + optional1);Optional<String> optional2 = Optional.ofNullable(null);System.out.println("\n\nOptional2: " + optional2);System.out.println("Optional2.isPresent: " + optional2.isPresent());}}
In the above code:
Optional class.import java.util.Optional;
ofNullable() method to get an Optional object of the Integer type with value 1.Optional<Integer> optional1 = Optional.ofNullable(1);
optional1;// Optional[1]
ofNullable() method with null as an argument. This method returns an empty Optional object because we send null as the value for the Optional object.Optional<String> optional2 = Optional.ofNullable(null);
optional2;// Optional.empty
optional2.isPresent(); // false