Question

这是我的代码：

public class LocationIntentService extends IntentService{

JSONParser parser=new JSONParser();
public int idMax=0,success=-1;


private int idAccident,rating,idTypef;
private float logitude,latitude;
private String date;

public ArrayList<Accident> allAccidents=new ArrayList<>();
Accident accident;
public ArrayList<Accident> a=new ArrayList<>();


public LocationIntentService() {
    super("LocationIntentService");

}

@Override
protected void onHandleIntent(Intent intent) {

       AlarmManager alarmManager = (AlarmManager)             getSystemService(ALARM_SERVICE);
        PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()   + 9000, pendingIntent);

    try {
            Log.i(TAG, "service has now started");
           new requestLocation().execute().get();

            Log.i(TAG, ""+allAccidents.size());
        }


        catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }



     }



    private class requestLocation extends AsyncTask<Void, Void, String> {
    @Override
    protected void onPreExecute() {

    }

    @Override
    protected String doInBackground(Void... params) {
        double lat,lon;

        String connect = Utility.lOCATION_SERVICE + "id=" + idMax;
        List<NameValuePair> params1 = new ArrayList<NameValuePair>();
        JSONObject json = parser.makeHttpRequest(connect, "POST", params1);
        if (json != null) {
            try {
                success = json.getInt("success");
                idMax= json.getInt("idMax");
                if (success == 1) {

                    JSONArray arr = json.getJSONArray("accidents");

                    for (int i = 0; i < arr.length(); i++) {
                        idAccident =      arr.getJSONObject(i).getInt("idAccident");

                        lon = arr.getJSONObject(i).getDouble("longitude");
                        logitude= (float) lon;

                        lat = arr.getJSONObject(i).getDouble("latitude");
                        latitude= (float) lat;

                        rating= arr.getJSONObject(i).getInt("rating");

                        date= arr.getJSONObject(i).getString("date");
                        idTypef= arr.getJSONObject(i).getInt("idTypef");

                        accident=new   Accident(idAccident,rating,idTypef,logitude,latitude,date);
                        allAccidents.add(accident);

                    }


                }
            }catch(JSONException e){
                e.printStackTrace();
            }
        }
        return null;
    }
    @Override
    protected void onPostExecute (String result){

    }
}

我的日志显示大小正在改变arraylist所以它工作得很好但问题是我不知道如何从另一个类访问这个arraylist所以我将此方法添加到此类

      public ArrayList<Accident> getAccidents(){
        return this.allAccidents;

      }

我从另一个班级尝试过这个：

  ArrayList<Accident> all=new ArrayList<>();
  LocationIntentService l=new LocationIntentService();

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


       all=l.getAccidents();

        Toast.makeText(getApplicationContext(), " "+all.size(),     Toast.LENGTH_LONG).show();

}

但问题是吐司显示为0 所以任何人都可以帮助我PLZ

Answer 1

请更换此

@Override
protected void onHandleIntent(Intent intent) {

       AlarmManager alarmManager = (AlarmManager)             getSystemService(ALARM_SERVICE);
        PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()   + 9000, pendingIntent);

    try {
            Log.i(TAG, "service has now started");
           new requestLocation().execute().get();

            Log.i(TAG, ""+allAccidents.size());
        }


        catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }



     }

由此

private Handler handler;
@Override
    protected void onHandleIntent(Intent intent) {

            handler = new Handler();
            Timer timer = new Timer();
            TimerTask hourlyTask = new TimerTask() {
                @Override
                public void run () {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {

                            try {
                                Log.i(TAG, "service has now started");
                                new requestLocation().execute().get();
                                Log.i(TAG, "size :"+allAccidents.size());
                                Log.i(TAG, "id : "+idMax);
                            }

                            catch (InterruptedException e) {
                                e.printStackTrace();
                            } catch (ExecutionException e) {
                                e.printStackTrace();
                            }



                        }
                    });
                }
            };
            timer.schedule(hourlyTask, 0l, 9000);

    }

访问从数据库读取的数据从另一个类

1 个答案: