Java 获取网络重定向URL

import java.net.HttpURLConnection;import java.net.URL;import org.junit.Assert;import org.junit.Test;public class GetRedirectUrlTest {@Testpublic void test_getRedirectUrl() throws Exception {String url="http://www.baidu.com/link?url=ByBJLpHsj5nXx6DESXbmMjIrU5W4Eh0yg5wCQpe3kCQMlJK_RJBmdEYGm0DDTCoTDGaz7rH80gxjvtvoqJuYxK";String expectUrl="http://www.zhihu.com/question/20583607/answer/16597802";String redictURL = getRedirectUrl(url);Assert.assertEquals(expectUrl, redictURL);}    /**     * 获取重定向地址     * @param path     * @return     * @throws Exception     */private String getRedirectUrl(String path) throws Exception {HttpURLConnection conn = (HttpURLConnection) new URL(path).openConnection();conn.setInstanceFollowRedirects(false);conn.setConnectTimeout(5000);        return conn.getHeaderField("Location");}}