JAVA实现把一个List集合拆分成多个子LIST

/**
 * 将一组数据平均分成n组
 *
 * @param source 要分组的数据源
 * @param n      平均分成n组
 * @param <T>
 * @return
 */
public static <T> List<List<T>> averageAssign(List<T> source, int n) {
    List<List<T>> result = new ArrayList<List<T>>();
    int remainder = source.size() % n;  //(先计算出余数)
    int number = source.size() / n;  //然后是商
    int offset = 0;//偏移量
    for (int i = 0; i < n; i++) {
        List<T> value = null;
        if (remainder > 0) {
            value = source.subList(i * number + offset, (i + 1) * number + offset + 1);
            remainder--;
            offset++;
        } else {
            value = source.subList(i * number + offset, (i + 1) * number + offset);
        }
        result.add(value);
    }
    return result;
}
/**
 * 将一组数据固定分组,每组n个元素
 * @param source 要分组的数据源
 * @param n      每组n个元素
 * @param <T>
 * @return
 */
public static <T> List<List<T>> fixedGrouping(List<T> source, int n) {

    if (null == source || source.size() == 0 || n <= 0)
        return null;
    List<List<T>> result = new ArrayList<List<T>>();

    int sourceSize = source.size();
    int size = (sourceSize % n) == 0 ? (sourceSize / n) : ((source.size() / n) + 1);
    for (int i = 0; i < size; i++) {
        List<T> subset = new ArrayList<T>();
        for (int j = i * n; j < (i + 1) * n; j++) {
            if (j < sourceSize) {
                subset.add(source.get(j));
            }
        }
        result.add(subset);
    }
    return result;
}
/**
 * 将一组数据固定分组,每组n个元素
 *
 * @param source 要分组的数据源
 * @param n      每组n个元素
 * @param <T>
 * @return
 */
public static <T> List<List<T>> fixedGrouping2(List<T> source, int n) {

    if (null == source || source.size() == 0 || n <= 0)
        return null;
    List<List<T>> result = new ArrayList<List<T>>();
    int remainder = source.size() % n;
    int size = (source.size() / n);
    for (int i = 0; i < size; i++) {
        List<T> subset = null;
        subset = source.subList(i * n, (i + 1) * n);
        result.add(subset);
    }
    if (remainder > 0) {
        List<T> subset = null;
        subset = source.subList(size * n, size * n + remainder);
        result.add(subset);
    }
    return result;
}
    /*
     * 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);
}

 

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转载自blog.csdn.net/bj_chengrong/article/details/103693040