无法使用 android 加载 URL

Question

我想检查应用程序的更新；我使用此功能，但它不起作用，并在第一次和第二次尝试中捕获。这是什么问题？

当你想下载页面时，你可以看到它的一些日志：

http://pasteboard.co/hn2hx7t.png

void CheckForUpdate()
        {
            handler.post(new Runnable() {

                @Override
                public void run() {

                    try
                    {
                        URL versionURL = new URL("http://sth.com/daycounter/moharam_day_counter.php?p=widget_version_code");
                        URL widgetURL = new URL("http://sth.com/daycounter/moharam_day_counter.php?p=widget_url");
                        URLConnection urlConnection = versionURL.openConnection();

                        BufferedReader bufferReader = new BufferedReader(new InputStreamReader( urlConnection.getInputStream()));

                        String version = bufferReader.readLine();
                        Log.i("WP", ""+version);

                        if(Integer.parseInt(version) >= Integer.parseInt(versionCode))
                        {

                            bufferReader.close();
                            urlConnection = widgetURL.openConnection();
                            bufferReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                            String widgetURLString = bufferReader.readLine();
                            Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(widgetURLString));
                            ShowNotifyCation("", "***", intent, 1, R.drawable.icon_image, R.raw.alarm_sound);

                        }
                        bufferReader.close();
                    }
                    catch(Exception e)
                    {
                        e.printStackTrace();
                    }
                    if(!GetIsShowBeheshtNote())
                    {
                        try
                        {


                                URL beheshtIsCommingURL = new URL("http://http://sth.com/daycounter/moharam_day_counter.php?p=behesht_is_coming");
                                URL beheshtURL = new URL("http://sth.com/daycounter/moharam_day_counter.php?p=behesht_url");                
                                BufferedReader bufferReader = new BufferedReader(new InputStreamReader(beheshtIsCommingURL.openStream()));
                                String isComing = bufferReader.readLine();
                                if(Boolean.parseBoolean(isComing))
                                {
                                    bufferReader.close();
                                    bufferReader = new BufferedReader(new InputStreamReader(beheshtURL.openStream()));
                                    String beheshtURLString = bufferReader.readLine();
                                    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(beheshtURLString));
                                    ShowNotifyCation("", ******", intent, 2, R.drawable.icon_image, R.raw.alarm_sound);
                                    SetIsShowBeheshtNote();


                                }
                                bufferReader.close();
                        }   
                        catch(Exception e)
                        {

                        }
                    }
                }
            });
        }

Answer 1

您正在主线程上发出网络请求。主线程专用于 UI 操作，因此 android 强制您使用 AsynTasks 或 Threads。

创建一个新的 AsyncTask 并将您的下载逻辑添加到 doInBackground 方法并在 onPostExecute 中使用结果

来自谷歌的例子： http://developer.android.com/training/basics/network-ops/connecting.html

private class DownloadWebpageTask extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {

        // params comes from the execute() call: params[0] is the url.
        try {
            return downloadUrl(urls[0]);
        } catch (IOException e) {
            return "Unable to retrieve web page. URL may be invalid.";
        }
    }
    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        textView.setText(result);
   }
}