List<String> strings = Arrays.asList("abc", "", "bc", "efg", "abcd","", "jkl");
1.空字符串数量
Long count = strings.stream().filter(string->string.isEmpty()).count();
2.筛选后的列表
List<String> filtered = strings.stream().filter(string ->!string.isEmpty()).collect(Collectors.toList());
3.合并字符串
String mergedString = strings.stream().filter(string ->!string.isEmpty()).collect(Collectors.joining(", "));
4.列表
List<Integer> squaresList = numbers.stream().map( i ->i*i).distinct().collect(Collectors.toList());
5.统计
IntSummaryStatistics stats = integers.stream().mapToInt((x) ->x).summaryStatistics();
- 列表中最大的数:stats.getMax()
- 列表中最小的数:stats.getMin()
- 所有数之和:stats.getSum()
- 平均数:stats.getAverage()
