filter stream java 8 code example

Example 1: java stream filter

List<String> result = lines.stream()               
                .filter(line -> "theLineIWant".equals(line))
                .collect(Collectors.toList());

Example 2: java stream().filter()

NowJava8.java
package com.ricky.java8;

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

public class NowJava8 {

    public static void main(String[] args) {

        List<String> lines = Arrays.asList("spring", "node", "ricky");

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

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

    }

}12345678910111213141516171819202122

Example 3: java stream and filter

items.stream()
	.filter(s->s.contains("B"))
	.forEach(System.out::println);

Example 4: java 8 stream option

things.stream()
    .map(this::resolve)
    .filter(Optional::isPresent)
    .map(Optional::get)
    .findFirst();