Thursday, August 28, 2025
HomeLanguagesJavaOptional stream() method in Java with examples

Optional stream() method in Java with examples

The stream() method of java.util.Optional class in Java is used to get the sequential stream of the only value present in this Optional instance. If there is no value present in this Optional instance, then this method returns returns an empty Stream.

Syntax:

public Stream<T> stream()

Parameters: This method do not accept any parameter.

Return value: This method returns the sequential stream of the only value present in this Optional instance. If there is no value present in this Optional instance, then this method returns an empty Stream.

Below programs illustrate stream() method:

Note: Below programs require JDK 9 and above to execute.

Program 1:




// Java program to demonstrate
// Optional.stream() method
  
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // create a Optional
        Optional<Integer> op
            = Optional.of(9455);
  
        // print value
        System.out.println("Optional: "
                           + op);
  
        // get the Stream
        System.out.println("Getting the Stream:");
        op.stream().forEach(System.out::println);
    }
}


Output:

Optional: Optional[9455]
Getting the Stream:
9455

Program 2:




// Java program to demonstrate
// Optional.stream() method
  
import java.util.*;
  
public class GFG {
  
    public static void main(String[] args)
    {
  
        // create a Optional
        Optional<Integer> op
            = Optional.empty();
  
        // print value
        System.out.println("Optional: "
                           + op);
  
        try {
  
            // get the Stream
            System.out.println("Getting the Stream:");
            op.stream().forEach(System.out::println);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}


Output:

Optional: Optional.empty
Getting the Stream:

Reference: https://docs.oracle.com/javase/9/docs/api/java/util/Optional.html#stream–

Dominic
Dominichttp://wardslaus.com
infosec,malicious & dos attacks generator, boot rom exploit philanthropist , wild hacker , game developer,
RELATED ARTICLES

Most Popular

Dominic
32244 POSTS0 COMMENTS
Milvus
80 POSTS0 COMMENTS
Nango Kala
6615 POSTS0 COMMENTS
Nicole Veronica
11787 POSTS0 COMMENTS
Nokonwaba Nkukhwana
11833 POSTS0 COMMENTS
Shaida Kate Naidoo
6729 POSTS0 COMMENTS
Ted Musemwa
7010 POSTS0 COMMENTS
Thapelo Manthata
6684 POSTS0 COMMENTS
Umr Jansen
6699 POSTS0 COMMENTS