public static <T> List<List<T>> splitList(List<T> list, int len) {
    
    
        if (list == null || list.size() == 0 || len < 1) {
    
    
            return null;
        }
        List<List<T>> result = new ArrayList<List<T>>();
        int size = list.size();
        int count = (size + len - 1) / len;

        for (int i = 0; i < count; i++) {
    
    
            List<T> subList = list.subList(i * len, (Math.min((i + 1) * len, size)));
            result.add(subList);
        }
        return result;
    }