Ways to Convert Java Array to Stream

In Java, you can make use of several ways to convert an array to a stream. Here are four ways to do it:

1. Using Arrays.stream() method.
2. Using Stream.of() method.
3. Using Arrays.asList() method.
4. Using Stream.Builder() method.

Let's take a look at each of them one by one,

1. Using Arrays.stream() method.

import java.util.Arrays;
import java.util.stream.Stream;

public class ArrayToSteamExample1 {

    public static void main(String[] args) {
        
        //Our String Array
        String[] countryArray = {"China", "France", "USA", "Canada","Sweden"};
        
        //String array converted to Stream using Arrays.stream()
        Stream<String> countryStream = Arrays.stream(countryArray);
    }

}

2. Using Stream.of() method

import java.util.stream.Stream;

public class ArrayToSteamExample2 {

    public static void main(String[] args) {

        //Our String Array
        String[] countryArray = {"China", "France", "USA", "Canada","Sweden"};

        //String array converted to Stream using Arrays.stream()
        Stream<String> countryStream = Stream.of(countryArray);
    }

}

3. Using Arrays.asList() method

import java.util.Arrays;
import java.util.List;
import java.util.stream.Stream;

public class ArrayToSteamExample3 {

    public static void main(String[] args) {

        //Our String Array
        String[] countryArray = {"China", "France", "USA", "Canada","Sweden"};

        //Step 1: Convert Array to List
        List<String> countryList = Arrays.asList(countryArray);
        
        //Step 2: Convert List to Steam
        Stream<String> countryStream = countryList.stream();
    }

}

4. Using Stream.Builder() method

import java.util.stream.Stream;

public class ArrayToSteamExample4 {

    public static void main(String[] args) {

        //Our String Array
        String[] countryArray = {"China", "France", "USA", "Canada","Sweden"};

        //Create a Stream Builder object
        Stream.Builder<String> builder = Stream.builder();
        for (String country : countryArray) {
            builder.add(country);
        }
        
        Stream<String> countryStream = builder.build();
    }

}

In the above example the Stream class in Java provides a Builder() method that can be used to create a stream of elements.

Example: Output:

China
France
USA
Canada
Sweden