package com.nisum.java9Features.StreamApi;

import java.util.*;
import java.util.stream.*;

public class TestOfNullable {
    public static void main(String[] args) {
        List<String> l = new ArrayList<String>();
        l.add("A");
        l.add("B");
        l.add(null);
        l.add("C");
        l.add("D");
        l.add(null);
        System.out.println(l);
        List<String> l2 = l.stream().filter(o -> o != null).collect(Collectors.toList());
        System.out.println(l2);

        List<String> l3 = l.stream().flatMap(o -> Stream.ofNullable(o)).collect(Collectors.toList());
        System.out.println(l3);

        Map<String, String> m = new HashMap<>();
        m.put("A", "Apple");
        m.put("B", "Banana");
        m.put("C", null);
        m.put("D", "Dog");
        m.put("E", null);
        List<String> l4 = m.entrySet().stream().map(e -> e.getKey()).collect(Collectors.toList());
        System.out.println(l4);

        List<String> l5 = m.entrySet().stream().flatMap(e -> Stream.ofNullable(e.getValue())).collect(Collectors.toList());
        System.out.println(l5);
    }
}