Open In App

Stream ofNullable(T) method in Java with examples

Last Updated : 25 Apr, 2019
Comments
Improve
Suggest changes
Like Article
Like
Report
The ofNullable(T) method returns a sequential Stream containing a single element if this stream is non-null otherwise method returns an empty Stream. It helps to handle the null stream and NullPointerException. Syntax:
static <T> Stream<T> ofNullable(T t)
Parameters: This method accepts a single parameter t which is the single element of which the Stream is to be returned. Return value: This method returns a stream with a single element if the specified element is non-null, otherwise an empty stream. Below programs illustrate ofNullable(T) method: Program 1: Java
// Java program to demonstrate
// Stream.ofNullable() method

import java.util.stream.Stream;
public class GFG {

    public static void main(String[] args)
    {

        // Create a stream with null
        Stream<String> value
            = Stream.ofNullable(null);

        // Print values
        System.out.println("Values of Stream:");
        value.forEach(System.out::println);
    }
}
The output printed on console of IDE is shown below. Output: Program 2: Java
// Java program to demonstrate
// Stream.ofNullable method

import java.util.ArrayList;
import java.util.stream.Stream;
public class GFG {

    public static void main(String[] args)
    {

        // Create ArrayList containing names
        ArrayList<String> list = new ArrayList<String>();
        list.add("Aman");
        list.add("Suraj");
        list.add("Zufaq");

        // create a stream with ArrayList
        Stream<ArrayList<String> > value
            = Stream.ofNullable(list);

        // print values
        System.out.println("Values of Stream:");
        value.forEach(System.out::println);
    }
}
The output printed on console is shown below. Output: References: https://docs.oracle.com/javase/10/docs/api/java/util/stream/Stream.html#ofNullable(T)

Next Article
Practice Tags :

Similar Reads