分割ArrayList

Java8

测试代码：

final AtomicInteger counter = new AtomicInteger(0);
List<Integer> inputList = IntStream.range(1, 99).boxed().collect(Collectors.toList());
int size = 10;
Map<Integer, List<Integer>> map = inputList.stream()
    .peek(e-> System.out.println("counter: " + counter))
    .collect(Collectors.groupingBy(s -> counter.getAndIncrement() / size));
Collection<List<Integer>> values = map.values();
for (List<Integer> value : values) {
    System.out.println(value.size());
}

结果：

...
100
100
100
100
98

apache 工具类

引入工具：

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.4</version>
</dependency>

测试代码：

int targetSize = 100;
List<Integer> largeList = IntStream.range(1, 9999).boxed().collect(Collectors.toList());
List<List<Integer>> lists = ListUtils.partition(largeList, targetSize);
for (List<Integer> list : lists) {
    System.out.println(list.size());
}

结果：

...
10
10
10
10
10
8