java list随机抽取元素

/**     * 从list中随机抽取元素     *     * @param list     * @param n     * @return void     * @throws     * @Title: createRandomList     * @Description: TODO     */    private static List createRandomList(List list, int n) {        // TODO Auto-generated method stub        Map map = new HashMap();        List listNew = new ArrayList();        if (list.size() <= n) {            return list;        } else {            while (map.size() < n) {                int random = (int) (Math.random() * list.size());                if (!map.containsKey(random)) {                    map.put(random, "");                    System.out.println(random + "===========" + list.get(random));                    listNew.add(list.get(random));                }            }            return listNew;        }    }

扩展：
截取list

list.subList(0, 2);