HttpURLConnection : 服务器返回 HTTP 403 Forbidden

Question

我想用他的网址下载一个文件。我将 AsyncTask 与 HttpURLConnection 一起使用，但是当我收到响应代码时，服务器返回错误 403。我在 doInBackground 中使用了 HttpURLConnection。

代码 ：

@Override
protected String doInBackground(String... sUrl) {
    InputStream input = null;
    OutputStream output = null;
    HttpURLConnection connection = null;
    try {

        ext = FilenameUtils.getExtension(sUrl[0]);
        fileName = FilenameUtils.getBaseName(sUrl[0]);

        Log.i("Brieg", "storage : /storage/emulated/0/" + fileName + "." + ext);

        URL url = new URL(sUrl[0]);
        connection = (HttpURLConnection) url.openConnection();
        connection.connect();

        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            return "Server returned HTTP " + connection.getResponseCode() + " " + connection.getResponseMessage();
        }

        int fileLength = connection.getContentLength();

        input = connection.getInputStream();
        output = new FileOutputStream("/storage/emulated/0/" + fileName + "." + ext);

        byte data[] = new byte[4096];
        long total = 0;
        int count;
        while ((count = input.read(data)) != -1) {

            if (isCancelled()) {
                input.close();
                return null;
            }
            total += count;

            if (fileLength > 0)
                publishProgress((int) (total * 100 / fileLength));
            output.write(data, 0, count);
        }
    }
    catch (MalformedURLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    finally {
        try {
            if (output != null)
                output.close();
            if (input != null)
                input.close();
        }
        catch (IOException ignored) {
        }

        if (connection != null)
            connection.disconnect();
    }
    return null;

}

问题出在哪儿 ？

知道当我在浏览器中获取 URL 时，下载文件就会启动。

先感谢您。

Answer 1

原因应该是你没有设置用户代理：

connection = (HttpURLConnection) url.openConnection();   
connection.addRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:221.0) Gecko/20100101 Firefox/31.0"); // add this line to your code
connection.connect();