跳号查询实现

 	/**
     * 查找跳号 第一种方法只适合间隔一位跳号
     */
    @Test
    public void jumpNoQry() {

        //查询序列号
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("no");
        List<User> users = userMapper.selectList(wrapper);
        ArrayList<Integer> list = new ArrayList<>();
        for (User user : users) {
            list.add(user.getNo());
        }
        //排序
        Collections.sort(list);
        //存放跳号集合
        Integer m = 0;
        ArrayList<Integer> JumpNo = new ArrayList<>();
        for (int i = 1; i < list.size(); i++) {
            if (list.get(i) - list.get(i - 1) == 2) {
                m = list.get(i) - 1;
                JumpNo.add(m);
            }
        }
        System.out.println(JumpNo);
    }

 	/**
     * 跳号查询(通用)
     */
    @Test
    public void Jumpno() {

        //模拟前端传值
        int a = -10;
        int b = 10;

        List<Integer> list = new ArrayList<>();
        for (int i = a; i <= b; i++) {
            list.add(i);
        }
        //模拟数据库数据
        List<Integer> DbNo = new ArrayList<>();
        DbNo.add(1);
        DbNo.add(4);
        DbNo.add(5);
        DbNo.add(6);
        DbNo.add(7);
        DbNo.add(8);

        ArrayList<String> JumpNo = new ArrayList<>();

        for (Integer o : list) {
            if (!DbNo.contains(o)){
                String c = "11";
                JumpNo.add(o+c);
        }

    }
        System.out.println(JumpNo);
}