正则表达式爬网站sf证号

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Test {
    public static void main(String[] args) throws IOException {
        //爬sf证
        //创建一个URL对象
        URL url = new URL("https://m.sengzan.com/jiaoyu/29104.html");
        //连接网址
        URLConnection conn = url.openConnection();
        //创建对象去读取网络中的数据
        BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));
        String line;
        //获取正则表达式的对象p
        String regax = "[1-9]\d{5}(18|19|20)\d{2}(0\d|10|11|12)(0[1-9]|[1-2]\d|30|31)\d{3}[\dXx]";
        Pattern p = Pattern.compile(regax);
        while ((line = br.readLine()) != null) {
            //用文本匹配器的对象matcher按照p的规则去读取当前这一行信息
            Matcher mat = p.matcher(line);
            while (mat.find()) {
                System.out.println(mat.group());
            }
        }
        br.close();
    }
}