Java 获取网络重定向文件的真实URL

import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
 
public class Test2 {
    public static void main(String[] args) throws Exception {
        String str="http://f.youku.com/player/getFlvPath/sid/130258503437697_01/st/flv/fileid/03000201004DA277E47AC503E2C7936B543E15-DFED-EE85-31E0-869A7BE2F5B8?K=457eb55affadc5c5161b9af9&hd=0";
        URL url = new URL(str);
        HttpURLConnection conn=(HttpURLConnection)url.openConnection();
        conn.getResponseCode();
        String realUrl=conn.getURL().toString();
        conn.disconnect();
        System.out.println("真实URL:"+realUrl);
    }
}