JAVA EE: How to convert streams to other data sources

Friday, 20 October 2017

How to convert streams to other data sources | Streams in Java 8

Click here to watch in Youtube :
https://www.youtube.com/watch?v=mUM-ZbtrbXI&list=UUhwKlOVR041tngjerWxVccw

StreamDemo1.java

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

/**
 * Convert Streams to Other DataStructures
 * 
 * Get Collections using stream.collect(Collectors.toList()).
 */
public class StreamDemo1
{
    public static void main(String[] args)
    {
        Stream<String> stream = Stream.of("Peter", "John", "Ram");
        
        List<String> nameList = stream.collect(Collectors.toList());

        System.out.println(nameList);
    }

}

Output

[Peter, John, Ram]

StreamDemo2.java

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

/**
 * Convert Streams to Other DataStructures
 * 
 * Get arrays using stream.toArray(EntryType[]::new)
 */
public class StreamDemo2
{
    public static void main(String[] args)
    {
        List<Integer> numberList = new ArrayList<>();
        numberList.add(1);
        numberList.add(2);
        numberList.add(3);
        numberList.add(4);
        
        Stream<Integer> stream = numberList.stream();
        Integer[] evenArray = stream.filter(i -> i % 2 == 0).toArray(Integer[]::new);
        for (Integer integer : evenArray)
        {
            System.out.println(integer);
        }
    }

}