java获取短链short-url最终跳转地址

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class ShortUrlRedirect {
    public static String getFinalRedirectUrl(String shortUrl) throws Exception {
        HttpURLConnection.setFollowRedirects(false);
        HttpURLConnection con = (HttpURLConnection) new URL(shortUrl).openConnection();
        con.setRequestMethod("GET");
        con.setRequestProperty("User-Agent", "Mozilla/5.0");
        int responseCode = con.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK) {
            return shortUrl;
        } else if (responseCode == HttpURLConnection.HTTP_MOVED_PERM || responseCode == HttpURLConnection.HTTP_MOVED_TEMP) {
            String redirectUrl = con.getHeaderField("Location");
            redirectUrl = redirectUrl.replaceAll(" ", "%20");
            return getFinalRedirectUrl(redirectUrl);
        } else {
            return null;
        }
    }

    public static void main(String[] args) throws Exception {
        String shortUrl = "https://sourl.cn/c2XJ9j";
        String finalUrl = getFinalRedirectUrl(shortUrl);
        System.out.println(finalUrl);
    }
}

结果：