Question

当我更新服务器上的JSON文件时，Android设备没有获取更新的文件，但是模拟器工作正常，模拟器正在从服务器获取并显示更新的文件。有没有办法通过代码刷新json文件，或者删除服务器缓存中的文件。

AsynTask用于从网络服务器获取视频网址。

private class fetchVideoUrls extends AsyncTask<String, String, List<VideoModel>> {

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

        @Override
        protected List<VideoModel> doInBackground(String... strings) {
            HttpURLConnection connection = null;
            BufferedReader reader = null;
            try {
                URL url = new URL(strings[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();
                InputStream stream = connection.getInputStream();
                reader = new BufferedReader(new InputStreamReader(stream));
                StringBuilder buffer = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    buffer.append(line);
                }

                String resultJson = buffer.toString();
                JSONObject parentObject = new JSONObject(resultJson);
                JSONArray parentArray = parentObject.getJSONArray("videos");

                List<VideoModel> videoModelList = new ArrayList<>();

                Gson gson = new Gson();
                for (int i = 0; i < parentArray.length(); i++) {
                    JSONObject finalObject = parentArray.getJSONObject(i);
                    VideoModel videoModel = gson.fromJson(finalObject.toString(), VideoModel.class);
                    videoModelList.add(videoModel);
                }
                return videoModelList;
            } catch (JSONException | IOException e) {
                e.printStackTrace();
            } finally {
                if (connection != null) {
                    connection.disconnect();
                }
                try {
                    if (reader != null) {
                        reader.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(List<VideoModel> result) {
            super.onPostExecute(result);
            dialog.dismiss();
            VideoAdapter adapter = new VideoAdapter(getApplicationContext(), R.layout.video_row, result);
            lvVideos.setAdapter(adapter);
        }
    }

Answer 1

您是否尝试在openConnection 之前在HttpURLConnection上设置缓存，方法 setUseCaches ？

方法参考：http://download.java.net/jdk7/archive/b123/docs/api/java/net/URLConnection.html#setUseCaches(boolean)

此方法继承自URLConnection类，如下所述：http://download.java.net/jdk7/archive/b123/docs/api/java/net/HttpURLConnection.html

Android未获取更新的JSON文件

1 个答案: