Java 8 example Streams filter

Before Java8

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

public class BeforeJava8 {

    public static void main(String[] args) {

        List lines = Arrays.asList("spring", "node", "java7");
        List result = getFilterOutput(lines, "java7");
        for (String temp : result) {
            System.out.println(temp);    //output : spring, node
        }

    }

    private static List getFilterOutput(List lines, String filter) {
        List result = new ArrayList<>();
        for (String line : lines) {
            if (!"java7".equals(line)) { // we dont like java7
                result.add(line);
            }
        }
        return result;
    }

}

Output

spring
node

The equivalent example in Java 8, stream.filter() to filter a List, and collect() to convert a stream into a List

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

public class NowJava8 {

    public static void main(String[] args) {

        List lines = Arrays.asList("spring", "node", "java7");

        List result = lines.stream()                // convert list to stream
                .filter(line -> !"java7".equals(line))     // we dont like java7
                .collect(Collectors.toList());              // collect the output and convert streams to a List

        result.forEach(System.out::println);                //output : spring, node

    }

}

Output

spring
node