Question

我正在尝试从文本文件中获取数据。假设文件的路径为 http://mywebsite.com/dir1/dir2/my_file.txt

请告诉我一种将此数据复制到字符串或直接将此文件保存在设备上的方法。

我也尝试过其他链接，但无法找到一个好的解决方案！有没有人可以用简单的词语解释一下？

Answer 1

在提出问题之前，请先尝试搜索一下！

使用异步任务call like new DownloadFileFromURL().execute(file_url);

需要用户权限<uses-permission android:name="android.permission.INTERNET" />

class DownloadFileFromURL extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Bar Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(progress_bar_type);
    }

    /**
     * Downloading file in background thread
     * */
    @Override
    protected String doInBackground(String... f_url) {
        int count;
        try {
            URL url = new URL(f_url[0]);
            URLConnection conection = url.openConnection();
            conection.connect();

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

            // download the file
            InputStream input = new BufferedInputStream(url.openStream(),
                    8192);

            // Output stream
            OutputStream output = new FileOutputStream(Environment
                    .getExternalStorageDirectory().toString()
                    + "/yourfilename.txt");

            byte data[] = new byte[1024];

            long total = 0;

            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                // After this onProgressUpdate will be called
                publishProgress("" + (int) ((total * 100) / lenghtOfFile));

                // writing data to file
                output.write(data, 0, count);
            }

            // flushing output
            output.flush();

            // closing streams
            output.close();
            input.close();

        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }

        return null;
    }

    /**
     * Updating progress bar
     * */
    protected void onProgressUpdate(String... progress) {
        // setting progress percentage
        pDialog.setProgress(Integer.parseInt(progress[0]));
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    @Override
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after the file was downloaded
        dismissDialog(progress_bar_type);

    }

}

如何以编程方式从android中的网站获取文本文件？

1 个答案: