Gets only designated several data array

1, you want to get an array of several unique data by an array of content

  @Test
    public void t74() {
        String[] arrStr = {"2092314", "2092313", "2078103", "588506", "353867", "337220", "337221", "337233", "337189", "318945"};
        HashSet<String> getrunmber = getrunmber(1, arrStr);
        getrunmber.forEach(m -> Log.info(m));

    }

    /**
     * 根据数组长，返回唯一相应数据
     * @param n
     * @param str
     * @return
     */
    public HashSet<String> getrunmber(int n, String[] str) {
        Random random = new Random();
        HashSet<String> setlist = new HashSet<>();
        if (n <= str.length && n != 0 && str.length != 0 && str != null) {
            while (setlist.size() < n) {
                int c = random.nextInt(str.length);
                setlist.add(str[c]);
            }
        } else {
            Log.info("获取的数据大于String数据的长度");
            return null;
        }
        return setlist;
    }