In this tutorial, we will demonstrate the different ways to create Optional class objects in Java.
The Optional class was introduced in Java 8 to avoid null checks and NullPointerException.
The Optional class provides empty(), of(), ofNullable() methods to create it's objects.
Create Optional Class Object in Java - empty(), of(), ofNullable() Methods
There are several ways of creating Optional objects.
empty() Method
To create an empty Optional object, we simply need to use its empty() static method: Optional<Object> emptyOptional = Optional.empty();
of() Method
The of() static method returns an Optional with the specified present non-null value.
Optional<String> emailOptional = Optional.of("ramesh@gmail.com");
ofNullable() Method
The ofNullable() static method returns an Optional describing the specified value, if non-null, otherwise returns an empty Optional. Optional<String> stringOptional = Optional.ofNullable("ramesh@gmail.com");
Here is the complete example with output:
import java.util.Optional;
public class OptionalDemo {
public static void main(String[] args) {
String email = "ramesh@gmail.com";
// of, empty, ofNullable
Optional<Object> emptyOptional = Optional.empty();
System.out.println(emptyOptional);
Optional<String> emailOptional = Optional.of(email);
System.out.println(emailOptional);
Optional<String> stringOptional = Optional.ofNullable(email);
System.out.println(stringOptional);
}
}
Output:
Optional.empty
Optional[ramesh@gmail.com]
Optional[ramesh@gmail.com]
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