Stream builder() in Java with Examples

Last Updated : 06 Dec, 2018

Stream builder() returns a builder for a Stream. Syntax :

static <T> Stream.Builder<T> builder()

where, T is the type of elements.

Return Value : A stream builder. Example 1 :

Java

// Java code for Stream builder()
import java.util.*;
import java.util.stream.Stream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Using Stream builder()
        Stream.Builder<String> builder = Stream.builder();

        // Adding elements in the stream of Strings
        Stream<String> stream = builder.add("Geeks").build();

        // Displaying the elements in the stream
        stream.forEach(System.out::println);
    }
}

Output :

Geeks

Example 2 :

Java

// Java code for Stream builder()
import java.util.*;
import java.util.stream.Stream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Using Stream builder()
        Stream.Builder<String> builder = Stream.builder();

        // Adding elements in the stream of Strings
        Stream<String> stream = builder.add("Geeks")
                                    .add("for")
                                    .add("Geeks")
                                    .add("GeeksQuiz")
                                    .build();

        // Displaying the elements in the stream
        stream.forEach(System.out::println);
    }
}

Output :

Geeks
for
Geeks
GeeksQuiz

Example 3 :

Java

// Java code for Stream builder()
import java.util.*;
import java.util.stream.Stream;
import java.util.stream.Collectors;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Using Stream builder()
        Stream.Builder<String> builder = Stream.builder();

        // Adding elements in the stream of Strings
        Stream<String> stream = builder.add("GEEKS")
                                    .add("for")
                                    .add("Geeks")
                                    .add("GeEKSQuiz")
                                    .build();

        // Converting elements to Lower Case
        // and storing them in List list
        List<String> list = stream.map(String::toLowerCase)
                                .collect(Collectors.toList());

        // Displaying the elements in list
        System.out.println(list);
    }
}