android - 发现 httpresponseexception 302

Question

使用 Google Drive 的这个功能，我得到一个 httpresponseexception。有谁知道为什么？

public static InputStream downloadFile(Drive service, String myurl) {
if (myurl != null && myurl.length() > 0) {
    try {
        HttpResponse resp = service.getRequestFactory().buildGetRequest(new GenericUrl(myurl))
            .execute();
         System.out.println("***********"+resp.getContent());
         return resp.getContent();
    } catch (IOException e) {
        // An error occurred.
        e.printStackTrace();
        return null;
    }
    } else {
        // The file doesn't have any content stored on Drive.
        return null;
    }
}