问题描述
长话短说。我的应用程序启动时，我想从互联网上下载一些谷歌表文件。情况如下：
Long story short. I want to download some google sheet files from the internet when my App starts. Here's the situation:
较新的设备：一切正常，没有问题，所有文件都已下载。
Newer Devices: Everything works 100%, no problems, all files downloaded.
旧设备（API 16-17）：正确下载第一个工作表文件。 无法下载第二个文件。我收到 HTTP / 1.1 302暂时移动问题，文件无法正确下载。
Older Devices (API 16-17): Downloads first sheet file correctly. Fails to download the second file. I get a HTTP/1.1 302 Moved Temporarily problem and file fails to download itself correctly.
我为这两个文件调用了AsynchTask。 AsynchTask运行完美，我尝试了其他方法来查看AsynchTask是否存在问题。此外，所有链接都非常精细且有效。
I call AsynchTask for both files. AsynchTask runs perfectly and I tried other methods to see if AsynchTask was the problem. In addition, all links are perfectly fine and working.
这是我的AsynchTask类代码的一部分：
Here is a part of my AsynchTask class code:
下载文件的方法：
private String downloadUrl(String urlString) throws IOException {
InputStream is = null;
try {
URL url = new URL(urlString);
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
conn.setInstanceFollowRedirects(true); //you still need to handle redirect manully.
HttpsURLConnection.setFollowRedirects(true);
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setInstanceFollowRedirects(true);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
int responseCode = conn.getResponseCode();
is = conn.getInputStream();
String contentAsString = convertStreamToString(is);
Log.d("contentAsString",contentAsString);
return contentAsString;
} finally {
if (is != null) {
is.close();
}
}
}
字符串结果（HTTP / 1.1） 302暂时移动消息）
String result (HTTP/1.1 302 Moved Temporarily message)
HTTP/1.1 302 Moved Temporarily
Content-Type: text/html; charset=UTF-8
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: Mon, 01 Jan 1990 00:00:00 GMT
Date: Tue, 18 Oct 2016 09:26:14 GMT
Location: https://docs.google.com/spreadsheets/d/1hRiDvdLPkQEdTSVxmWEoWXjmCFQodNjMNYi3Fd7yYn0/gviz/tq
P3P: CP="This is not a P3P policy! See https://support.google.com/accounts/answer/151657?hl=en for more info."
P3P: CP="This is not a P3P policy! See https://support.google.com/accounts/answer/151657?hl=en for more info."
Content-Encoding: gzip
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Server: GSE
Set-Cookie: NID=89=afVN4Sa74ZsYuffxNSiXn2wWTJkSUULbtZperbpr8T9hPzHoFzx-uGu_lJUVCkYSd1eZUPUFucffCDHc7lPConnfPpTMbqAOgIcIQoJG6TQFUHzBUNW6bFqUy__ZthsR;Domain=.google.com;Path=/;Expires=Wed, 19-Apr-2017 09:26:14 GMT;HttpOnly
Set-Cookie: NID=89=k5r33ZLA4l__4v1CE1iGrtQbtqoJxOyVxwrSMbsKWviK74u-vM32WdKtt-txFEOhPWo1g9f1CWMXcu6Fuczo4ZCck47D23tIZZRcqpRxkSB0z5w2xI9oj1Jcq8duISiU;Domain=.google.com;Path=/;Expires=Wed, 19-Apr-2017 09:26:14 GMT;HttpOnly
Alt-Svc: quic=":443"; ma=2592000; v="36,35,34,33,32"
Transfer-Encoding: chunked
00000001
00000001
�
00000001
00000001
��
00000001
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00000001
��
00000001
��
00000001
��
00000001
��
00000001
��
00000001
m
00dc
��N�0D��
�ܳ�8 !7R�8)ih�hs��U�R�!6��q
G����HoY!�2�X����,J�TfFI��L�4�� ~����Z�~��eݬ�]D����E��.�k�n$i��/���r,%E��U��gl�ӟ1>
v���V!: ���Y�/�;.��ۗ�s�?��&��=U�v���õ�,���op4Q8!�4�=�
%��O����ڛ�����
0
在阅读了一些关于HTTP 302之后，我知道我必须以某种方式重定向。问题是我不知道该怎么做。此外，我不知道为什么这个问题只出现在较旧的Android版本上。
After reading a bit about HTTP 302 I know I have to redirect somehow. Problem is I have no idea how to do this. Also, I have no idea why this problem only appears on older android versions.
我现在已经挣扎了一个星期。任何反馈意见！谢谢！
I've struggling for a week now. Any feedback appreciated! Thank you!
推荐答案
关注重定向的关键是按键位置并将其用作您的网址：
The key to following a redirect is to take the header by key location and use that as your URL instead:
Location: https://docs.google.com/spreadsheets/d/1hRiDvdLPkQEdTSVxmWEoWXjmCFQodNjMNYi3Fd7yYn0/gviz/tq
这只是网络服务器的说法嘿，你的页面移到这里。转到那里！。
It is just the web servers way of saying "Hey, your page moved over here. Go there instead!".
This article by mkyong.com has a good example:
package com.mkyong.http;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class HttpRedirectExample {
public static void main(String[] args) {
try {
String url = "http://www.twitter.com";
URL obj = new URL(url);
HttpURLConnection conn = (HttpURLConnection) obj.openConnection();
conn.setReadTimeout(5000);
conn.addRequestProperty("Accept-Language", "en-US,en;q=0.8");
conn.addRequestProperty("User-Agent", "Mozilla");
conn.addRequestProperty("Referer", "google.com");
System.out.println("Request URL ... " + url);
boolean redirect = false;
// normally, 3xx is redirect
int status = conn.getResponseCode();
if (status != HttpURLConnection.HTTP_OK) {
if (status == HttpURLConnection.HTTP_MOVED_TEMP
|| status == HttpURLConnection.HTTP_MOVED_PERM
|| status == HttpURLConnection.HTTP_SEE_OTHER)
redirect = true;
}
System.out.println("Response Code ... " + status);
if (redirect) {
// get redirect url from "location" header field
String newUrl = conn.getHeaderField("Location");
// get the cookie if need, for login
String cookies = conn.getHeaderField("Set-Cookie");
// open the new connnection again
conn = (HttpURLConnection) new URL(newUrl).openConnection();
conn.setRequestProperty("Cookie", cookies);
conn.addRequestProperty("Accept-Language", "en-US,en;q=0.8");
conn.addRequestProperty("User-Agent", "Mozilla");
conn.addRequestProperty("Referer", "google.com");
System.out.println("Redirect to URL : " + newUrl);
}
BufferedReader in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer html = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
html.append(inputLine);
}
in.close();
System.out.println("URL Content... \n" + html.toString());
System.out.println("Done");
} catch (Exception e) {
e.printStackTrace();
}
}
}
这篇关于HTTP / 1.1 302暂时移动 - 在Android API 16-17上发生的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！