java实现把一个List集合拆分成多个的操作

  /*
   * List分割
   */
  public static List<List<String>> groupList(List<String> list) {
    List<List<String>> listGroup = new ArrayList<List<String>>();
    int listSize = list.size();
    //子集合的长度
    int toIndex = 2;
    for (int i = 0; i < list.size(); i += 2) {
      if (i + 2 > listSize) {
        toIndex = listSize - i;
      }
      List<String> newList = list.subList(i, i + toIndex);
      listGroup.add(newList);
    }
    return listGroup;
  }
 
public static void main(String[] args) {
    List<String> list = new ArrayList<>();
    list.add("1");
    list.add("2");
    list.add("3");
    list.add("4");
    list.add("5");
    list.add("6");
    list.add("7");
    List<List<String>> lists = groupList(list);
    System.out.println("list:" + list.toString());
    System.out.println(lists);
}

 /**
   * 拆分集合
   * 
   * @param <T> 泛型对象
   * @param resList 需要拆分的集合
   * @param subListLength 每个子集合的元素个数
   * @return 返回拆分后的各个集合组成的列表
   * 代码里面用到了guava和common的结合工具类
   **/
  public static <T> List<List<T>> split(List<T> resList, int subListLength) {
    if (CollectionUtils.isEmpty(resList) || subListLength <= 0) {
      return Lists.newArrayList();
    }
    List<List<T>> ret = Lists.newArrayList();
    int size = resList.size();
    if (size <= subListLength) {
      // 数据量不足 subListLength 指定的大小
      ret.add(resList);
    } else {
      int pre = size / subListLength;
      int last = size % subListLength;
      // 前面pre个集合，每个大小都是 subListLength 个元素
      for (int i = 0; i < pre; i++) {
        List<T> itemList = Lists.newArrayList();
        for (int j = 0; j < subListLength; j++) {
          itemList.add(resList.get(i * subListLength + j));
        }
        ret.add(itemList);
      }
      // last的进行处理
      if (last > 0) {
        List<T> itemList = Lists.newArrayList();
        for (int i = 0; i < last; i++) {
          itemList.add(resList.get(pre * subListLength + i));
        }
        ret.add(itemList);
      }
    }
    return ret;
  }
 
// 运行代码
public static void main(String[] args) {
  List<String> list = Lists.newArrayList();
  int size = 1099;
  for (int i = 0; i < size; i++) {
    list.add("hello-" + i);
  }
 
  List<List<String>> temps = split(list, 6);
  int j = 0;
  for (List<String> obj : temps) {
    System.out.println(String.format("row:%s -> size:%s,data:%s", ++j, obj.size(), obj));
  }
}

public static void main(String[] args) {
  List<String> list = Lists.newArrayList();
  int size = 1099;
  for (int i = 0; i < size; i++) {
    list.add("hello-" + i);
  }
  // 切割大集合到指定的长度：11
  List<List<String>> rsList = Lists.partition(list, 11);
  int i = 0;
  for (List<String> obj : rsList) {
    System.out.println(String.format("row:%s -> size:%s,data:%s", ++i, obj.size(), obj));
  }
}