文件下载挂起

Question

经过广泛的搜索，我无法找到解决文件下载问题的解决方案。

以下脚本旨在通过WebViewClient.从远程(Hotmail)服务器下载csv文件

登录过程是通过他们的标准网站，但我想捕获下载的csv文件使用以下下载类，并存储在一个自定义的位置。

它适用于直接链接到例如，site.com/file.pdf的文件的URL，但不会在处理过的URL(如site.com/downloadFile.php?n=xxxx )上工作，在那里它只是挂起，直到远程服务器重新设置连接。

    private class DownloadFile extends AsyncTask<String, Integer, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog.show();
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        super.onProgressUpdate(progress);
        mProgressDialog.setProgress(progress[0]);
    }

     @Override
     protected void onPostExecute (String result){

     super.onPostExecute(result);

     mProgressDialog.dismiss();
     mProgressDialog = null;
     }


    @Override
    protected String doInBackground(String... sUrl) {

        try {

            Log.i("File download", "Started from :"+sUrl[0]);

            URL url = new URL(sUrl[0]);
            //URLConnection connection = url.openConnection();
            File myDir = new File(Environment.getExternalStorageDirectory() + "/myDir");

            // create the directory if it doesnt exist
            if (!myDir.exists()) myDir.mkdirs();            

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();


            //Follow redirects so as some sites redirect to the file location
            connection.setInstanceFollowRedirects(true);        
            connection.setDoOutput(true);           

            connection.connect();

            File outputFile     =   new File(myDir, "hotmail_contacts.csv");

            // this will be useful so that you can show a typical 0-100%
            // progress bar
            int fileLength      = connection.getContentLength();

            // download the file
            InputStream input   = new BufferedInputStream(url.openStream());                
            OutputStream output = new FileOutputStream(outputFile);

            byte data[] = new byte[1024];
            long total = 0;
            int count;

            while ((count = input.read(data)) != -1) {

                total += count;
                // publishing the progress....
                publishProgress((int) (total * 100 / fileLength));
                output.write(data, 0, count);
            }


            connection.disconnect();
            output.flush();
            output.close();
            input.close();

            Log.i("File download", "complete");

        } catch (Exception e) {

            Log.e("File download", "error: " + e.getMessage());

        }
        return null;
    }
}

在onDownloadStart(....)方法中调用上述AsyncTask，如下所示：

public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimeType, long length) {

        Log.i("File download", "URL:" + url 
                + " UserAgent:" + userAgent
                + "ContentDisposition:" + contentDisposition 
                + "Mime:"+ mimeType + "Length:" + Long.toString(length));



        // instantiate it within the onCreate method
        mProgressDialog = new ProgressDialog(Email_import.this);
        mProgressDialog.setMessage("File download");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.setMax(100);
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);

        // start a new download
        DownloadFile downloadFile = new DownloadFile();
        downloadFile.execute(url);

    }// end onCreate

所有相关权限都在清单中，如写入外部存储、internet和读取网络状态。

我是不是漏掉了什么？任何帮助都将不胜感激。

Answer 1

在看了另一篇文章之后

1：Download a file from webview to a custom folder，我已经对我的代码做了一些调整，使用一个HttpClient对象将URL作为HttpPost请求调用，如下所示，它看起来工作得很好：

                // Create client and set our specific user-agent string
            HttpClient client = new DefaultHttpClient();
            HttpPost request = new HttpPost(sUrl[0]);               
            request.setHeader("User-Agent", sUrl[1]);               

            HttpResponse response = client.execute(request);

            Log.i("File download", "Started from :" + sUrl[0]);

            File myDir = new File(Environment.getExternalStorageDirectory() + "/myDir");

            // create the directory if it doesnt exist
            if (!myDir.exists())    myDir.mkdirs();

            File outputFile = new File(myDir, "hotmail_contacts.csv");

            InputStream input   = response.getEntity().getContent();