import stream.genetator.CollectionStreamGenerator; import stream.util.CollectUtils; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** * @Author xiongyx * on 2019/3/8. */ public class FlatMapTest { public static void main(String[] args){ testCollectionGenerator(); } private static void testCollectionGenerator(){ List teamIndia = Arrays.asList("11", "12", "13"); List teamAustralia = Arrays.asList("21", "22", "23","24"); List teamEngland = Arrays.asList("31", "32", "33"); List teamNewZeland = Arrays.asList("41", "42", "43"); List teamSouthAfrica = Arrays.asList("52", "53"); List> playersInWorldCup2016 = new ArrayList<>(); playersInWorldCup2016.add(teamIndia); playersInWorldCup2016.add(teamAustralia); playersInWorldCup2016.add(teamEngland); playersInWorldCup2016.add(teamNewZeland); playersInWorldCup2016.add(teamSouthAfrica); List list = CollectionStreamGenerator.getListStream(playersInWorldCup2016) .flatMap(CollectionStreamGenerator::getListStream) .filter(item->item.endsWith("2")) .limit(2) .collect(CollectUtils.toList()); list.forEach(System.out::println); // .forEach(System.out::println); } }