刷新json线程以解析特定时间间隔的数据

Question

理想情况下我想实施

方法级同步，其中整个方法每1分钟同步

不

块级同步，其中只有一组语句被同步

但我不知道为什么我的新runnable处理程序在设定的时间间隔执行该方法。它会一次又一次地解析未更改的json数据，并以冗余方式填充我的listview。

如何实现一个处理程序，该处理程序只解析从前60秒更改/更新的json中的数据，而不重复列表视图上的数据？

    private class MyAsyncTask extends AsyncTask<Void, Void, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        dialog = new ProgressDialog(RegionListActivity.this);
        dialog.setMessage("Please wait..");
        dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
        dialog.show();
    }

    @Override
    protected String doInBackground(Void... params) {
        String url_structure = GlobalData.MAIN_URL + sessionId
                + "/user_session/?sections=app-basic&company_id="
                + companyId;
        String response_structure = CallWebService
                .getResponseOfUrl(url_structure);
        parseRegionList(response_structure);

        String url_unit = GlobalData.MAIN_URL + sessionId
                + "/reporting/system/unit_status/?sections&company_id="
                + companyId;
        String response_unit = CallWebService.getResponseOfUrl(url_unit);
        parseUnitStatus(response_unit);
        return null;

    }

    @SuppressWarnings("null")
    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
        dialog.dismiss();

        if (!alRegions.isEmpty() && !alParents.isEmpty()) {
            expandableAdapter = new ExpandableListAdapter(
                    RegionListActivity.this, alParents);
            lvExpandableRL.setAdapter(expandableAdapter);

            GlobalData.alAssetsGlobal = hashMapAssets;
            GlobalData.alComponetsGlobal = hashMapComponents;

        }

        else {
            lvExpandableRL.setVisibility(View.GONE);
            tvNoRecordsRL.setVisibility(View.VISIBLE);
        }

        tvCompanyNameRL.setText(GlobalData.COMPANY_NAME);
        tvActiveAlarmsRL.setText(GlobalData.ACTIVE_ALARMS);
        tvUnitsOfflineRL.setText(GlobalData.OFFLINE_COUNT);

        /*
         * try { if(alUnitNumber.size()>0 && alUnitNumber != null) {
         * al_unit_snumber=alUnitNumber;
         * lvUnitsOffline.setVisibility(View.VISIBLE); adapter= new
         * UnitListAdapter(RegionListActivity.this, alUnitNumber);
         * lvUnitsOffline.setAdapter(adapter); } else {
         * lvUnitsOffline.setVisibility(View.GONE);
         * tvNoRecordsUnitListOffline.setVisibility(View.VISIBLE); } } catch
         * (Exception e) { // TODO Auto-generated catch block
         * e.printStackTrace(); }
         * 
         * if(alUnitStatus.size()>0 && alUnitStatus != null)
         * 
         * alUnitStatus=(ArrayList<DataUnits>)getArguments()
         * .getSerializable(WebElement.RECORDS); if(alUnitStatus.size()>0 &&
         * alUnitStatus != null) { al_unit_snumber=alUnitNumber;
         * lvUnitsOffline.setVisibility(View.VISIBLE); adapter= new
         * UnitListAdapter(RegionListActivity.this, alUnitStatus);
         * lvUnitsOffline.setAdapter(adapter); } else {
         * lvUnitsOffline.setVisibility(View.GONE);
         * tvNoRecordsUnitListOffline.setVisibility(View.VISIBLE); }
         */

    }
    new Handler().postDelayed(new Runnable() {
        public void run() {
            // call JSON methods here
            new MyAsyncTask().execute();
        }
    }, 60000);

}