// "Fix all 'Stream API call chain can be replaced with loop' problems in file" "true" import java.util.*; import java.util.function.UnaryOperator; import java.util.stream.Collectors; public class Main { public static Map> test(List strings) { return strings.stream().filter(s -> !s.isEmpty()).collect(Collectors.partitioningBy(s -> s.length() > 1)); } static void testCounting(List list) { Map map2 = list.stream() .collect(Collectors.partitioningBy(String::isEmpty, Collectors.counting())); System.out.println(map2); } static void testSummingDouble(List list) { Map map1 = list.stream() .collect(Collectors.partitioningBy(String::isEmpty, Collectors.summingDouble(String::length))); System.out.println(map1); } public static void testGroupingToSet(List strings) { final Map>> nestedMap = strings.stream().collect(Collectors.partitioningBy((String s) -> s.length() > 2, Collectors.groupingBy(s -> s.charAt(0), Collectors.toSet()))); System.out.println(nestedMap); } public static void testToCollection(List strings) { System.out.println(strings.stream().collect(Collectors.partitioningBy(s -> s.length() > 2, Collectors.toCollection(LinkedHashSet::new)))); } public static void testToMapNameConflict(List strings) { System.out.println(strings.stream().map(x -> x/*trimming*/.trim()) // and collect .collect(Collectors.partitioningBy(s -> s.length() /*too big!*/ > 2, Collectors.toMap(s -> ((UnaryOperator) /* cast is necessary here */ x -> x = x).apply(s), String::length)))); } public static void main(String[] args) { System.out.println(test(Arrays.asList())); System.out.println(test(Arrays.asList("a", "bbb", "cc", "d", "eee", ""))); testCounting(Arrays.asList("a", "", "bbb", "c", "a", "")); testSummingDouble(Arrays.asList("a", "", "bbb", "c", "a", "")); testGroupingToSet(Arrays.asList("a", "bbb", "cccc", "dddd")); testToCollection(Arrays.asList("a", "bbb", "cccc", "dddd", "ee", "e", "e")); testToMapNameConflict(Arrays.asList("a", "bbb", "cccc", "dddd", "ee", "e", "e")); } }