有时无法从机器人的服务器获取数据和经度

Question

public class MobileActivity extends Activity {
    ArrayList<Actors> actorsList;

    public String latti;
    public String longi;
    ActorAdapter adapter;
    JSONParser jParser = new JSONParser();
     private static String url_search = "http://10.0.2.2/AndroidApp/mobile1.php";
     //String url_search = "http://10.0.2.2/AndroidApp/mobile1.php?lat="+lat+"&lon="+lon;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.offer_activity);

        actorsList = new ArrayList<Actors>();
        new JSONAsyncTask().execute(url_search);

        final ListView listview = (ListView)findViewById(R.id.list);
        adapter = new ActorAdapter(getApplicationContext(), R.layout.icons, actorsList);

        listview.setAdapter(adapter);

        Intent myIntent = getIntent();

        latti = myIntent.getStringExtra("lat");
        longi = myIntent.getStringExtra("lon");
     //Toast.makeText(this, latti, Toast.LENGTH_LONG).show();
  //Toast.makeText(this, longi, Toast.LENGTH_LONG).show();


        listview.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long id) {
                // TODO Auto-generated method stub
                //Toast.makeText(getApplicationContext(), actorsList.get(position).getId(), Toast.LENGTH_LONG).show();
                String pid=actorsList.get(position).getName();

              Intent intent = new Intent(MobileActivity.this,ProductDetails.class);
              intent.putExtra("keyid",pid.toString());
              startActivity(intent);
                //initiatePopupWindow();
            /*  LayoutInflater layoutInflater 
                 = (LayoutInflater)getBaseContext()
                  .getSystemService(LAYOUT_INFLATER_SERVICE);  
                View popupView = layoutInflater.inflate(R.layout.popup, null);
                         final PopupWindow popupWindow = new PopupWindow(
                           popupView, 
                           LayoutParams.WRAP_CONTENT,  
                                 LayoutParams.WRAP_CONTENT);  
                         Button btnDismiss = (Button)popupView.findViewById(R.id.dismiss);
                         btnDismiss.setOnClickListener(new Button.OnClickListener(){

                 @Override
                 public void onClick(View v) {
                  // TODO Auto-generated method stub
                  popupWindow.dismiss();
                 }});

                         popupWindow.showAsDropDown(listview, 10, -400);

}*/}
        });

    }

     @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.activity_main_actions, menu);
            android.app.ActionBar bar = getActionBar();
            bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#20B2AA")));
            return super.onCreateOptionsMenu(menu);
        }


     @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Take appropriate action for each action item click
            switch (item.getItemId()) {
            case R.id.hom:
                 Intent hom = new Intent(this, OpenApp.class);
                 startActivity(hom);
                return true;
            case R.id.grid:
                // search action
                 Intent searchIntent1 = new Intent(this, MobileGrid.class);
                 searchIntent1.putExtra("lat",latti.toString());
                 searchIntent1.putExtra("lon",longi.toString());
                 startActivity(searchIntent1);
                return true;

            default:
                return super.onOptionsItemSelected(item);
            }
        }

    class JSONAsyncTask extends AsyncTask<String, Void, Boolean> {

        ProgressDialog dialog;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            dialog = new ProgressDialog(MobileActivity.this);
            dialog.setMessage("Loading, please wait");
            dialog.setTitle("Connecting server");
            dialog.show();
            dialog.setCancelable(false);
        }

        @Override
        protected Boolean doInBackground(String... urls) {
            try {

                //------------------>>
                   List<NameValuePair> params = new ArrayList<NameValuePair>(2);
                   params.add(new BasicNameValuePair("lat", latti));
                   params.add(new BasicNameValuePair("lon", longi));



                //HttpGet httppost = new HttpGet(urls[0]);
                //HttpClient httpclient = new DefaultHttpClient();
                //HttpResponse response = httpclient.execute(httppost);

                // StatusLine stat = response.getStatusLine(); 
                //int status = response.getStatusLine().getStatusCode();

                //if (status == 200) {
                    //HttpEntity entity = response.getEntity();
                    //String data = EntityUtils.toString(entity);

                    JSONObject jsono = jParser.makeHttpRequest(url_search, "GET",params);
                    //JSONObject jsono = new JSONObject(data);
                     JSONArray jarray = jsono.getJSONArray("offer_reg"); 

                    for (int i = 0; i < jarray.length(); i++) {
                        JSONObject object = jarray.getJSONObject(i);

                        Actors actor = new Actors();

                        actor.setName(object.getString("offer_id"));
                        actor.setDescription(object.getString("lat"));
                        //actor.setDob(object.getString("dob"));
                        actor.setCountry(object.getString("log"));  
                        //actor.setHeight(object.getString("tag3"));
                        //actor.setSpouse(object.getString("tag4"));
                        //actor.setChildren(object.getString("tag1"));
                        actor.setImage(object.getString("offer_image")); 
                        actorsList.add(actor);
                    }
                    return true;
                //}
                //------------------>>

            } catch (ParseException e1) {
                e1.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return false;
        }

        protected void onPostExecute(Boolean result) {
            dialog.cancel();
            adapter.notifyDataSetChanged();
            if(result == false)
                Toast.makeText(getApplicationContext(), "Unable to fetch data from server", Toast.LENGTH_LONG).show();

        }
    }


}

无法从android中的服务器（PHP，mysql）获取数据，使用lattitude和longitude获取图像视图...显示某些时间图像视图...有时无法从服务器获取数据