http请求返回302处理方案

http发送淘宝客短链，请求返回302重定向，需要经过几次跳转后，最终得到请求返回内容。代码如下：

import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 解决淘宝客短链302跳转 / 商品数字ID转换工具类
 * (Tbk shortlink / num_iid convertor)
 */
public class ShorturlNumiidConvertUtil {
    public static void main(String[] args) {
        String shortLink = "http://s.click.taobao.com/Qpv0xTx";

        System.out.println("访问地址:" + shortLink);
        URL serverUrl = null;
        try {
            /**
             * 第一次跳转(短链 => 获取点击链接)
             */
            serverUrl = new URL(shortLink);
            HttpURLConnection conn1Jump = (HttpURLConnection) serverUrl
                    .openConnection();
            conn1Jump.setRequestMethod("GET");

            // 必须设置false，否则会自动redirect到Location的地址
            conn1Jump.setInstanceFollowRedirects(false);
            conn1Jump.connect();
            //response-header field,Location用于302重定向地址
            String location = conn1Jump.getHeaderField("Location");

            System.out.println("302第一次跳转地址:" + location);

            /**
             * 第二次跳转(点击链接 => 转换成js跳转链接)
             */
            serverUrl = new URL(location);
            HttpURLConnection conn2Jump = (HttpURLConnection) serverUrl
                    .openConnection();
            conn2Jump.setRequestMethod("GET");

            // 必须设置false，否则会自动redirect到Location的地址
            conn2Jump.setInstanceFollowRedirects(false);
            conn2Jump.connect();
            String locaTwo = conn2Jump.getHeaderField("Location");

            System.out.println("302第2次跳转地址:" + locaTwo);

            /**
             * 第三次跳转(js跳转链接 => 商品详情页)
             */
            String urlAfterDecode = URLDecoder.decode(locaTwo, "UTF-8").split("tu=")[1];
            serverUrl = new URL(urlAfterDecode);
            HttpURLConnection conn3Jump = (HttpURLConnection) serverUrl
                    .openConnection();
            conn3Jump.setRequestMethod("GET");
            conn3Jump.addRequestProperty("Referer", locaTwo);

            // 必须设置false，否则会自动redirect到Location的地址
            conn3Jump.setInstanceFollowRedirects(false);
            conn3Jump.connect();
            String locaThree = conn3Jump.getHeaderField("Location");

            System.out.println("302第3次跳转地址:" + locaThree);

            conn3Jump.disconnect();
            conn2Jump.disconnect();
            conn1Jump.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}