JAVA EE: How to use the Intermediate operations[filter, map and sorted] of Java 8 Stream

Monday 23 October 2017

How to use the Intermediate operations[filter, map and sorted] of Java 8 Stream | Streams in Java 8

Click here to watch in Youtube :
https://www.youtube.com/watch?v=284w36fLUTQ&list=UUhwKlOVR041tngjerWxVccw

StreamDemo1.java

import java.util.Arrays;
import java.util.List;

/**
 * Intermediate operation : filter()
 */
public class StreamDemo1
{
    public static void main(String[] args)
    {
        List<String> list = Arrays.asList("Welcome", "apple", "to", "India");

        /*
         * filter() operation helps eliminate elements based on certain
         * criteria.
         */
        list.stream().filter(element -> !"apple".equals(element))
                .forEach(element -> System.out.println(element));
    }

}

Output

Welcome
to
India

StreamDemo2.java

import java.util.Arrays;
import java.util.List;

/**
 * Intermediate operation : map()
 */
public class StreamDemo2
{
    public static void main(String[] args)
    {
        List<String> list = Arrays.asList("Welcome", "apple", "to","India");

        /*
         * map() operation helps map elements to the corresponding
         * results.
         */
        list.stream().filter(element -> !"apple".equals(element))
                .map(String::toUpperCase)
                .forEach(System.out::println);
    }

}

Output

WELCOME
TO
INDIA

StreamDemo3.java

import java.util.Arrays;
import java.util.List;

/**
 * Intermediate operation :sorted()
 */
public class StreamDemo3
{
    public static void main(String[] args)
    {
        List<String> list = Arrays.asList("Ball", "Cat", "Dog", "Apple");

        /*
         * sorted() operation helps sort elements based on certain
         * criteria.
         */
        list.stream().sorted().filter((element) -> !element.startsWith("D"))
                .map(String::toUpperCase)
                .forEach(System.out::println);
    }

}