TimerTask计划每15分钟刷新一次app数据。如何在课外执行一次timertask

Question

每隔15分钟安排一次TimerTask来刷新应用程序的数据。如何在没有感情计划的计时器任务的情况下在课外执行一次timertask。因为我必须每15分钟不断更新应用程序的数据。有一种情况我需要立即更新课外的数据。

public class SplashActivity extends AppCompatActivity {

 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);
        }
        final Handler handler = new Handler();
        timer = new Timer();




        TimerTask doAsynchronousTask = new TimerTask() {
            @Override
            public void run() {
                handler.post(new Runnable() {
                    public void run() {
                        try {
                            if (timer == null) {
                                cancel();
                            }
                            Boolean isInternetPresent = internetCheck.isConnectingToInternet();
                            if(isInternetPresent)
                            new MyAsyncTask().execute();
                            else
                                System.out.println("Internet connection not presents ");
                        } catch (Exception e) {
                            // TODO Auto-generated catch block
                        }
                    }
                });
            }
        };
        timer.schedule(doAsynchronousTask, 0, 900000);
        }

 public  class MyAsyncTask extends AsyncTask<String, String, String> {


        @Override
        protected String doInBackground(String... params) {
            long s_time = System.currentTimeMillis();
            android.util.Log.i("Start  ", " Time value in millisecinds " + s_time);
            String xmlDataOverHttp = PostData();
            long e_time = System.currentTimeMillis();
            android.util.Log.i("End  ", " Time value in millisecinds " + e_time);
            Myregistry registry= AppRegistry.getInstance();
            Serializer serializer = new Persister();
            MyObject example = null;
            try {
                example = serializer.read(MyObject.class, student_xml);
            } catch (Exception e) {
                e.printStackTrace();
            }
            SharedPreferences.Editor editor = sharedpreferences.edit();
            editor.putString(MyObjectXMl, xmlDataOverHttp);
            editor.apply();
            registry.setObject(example);
            return xmlDataOverHttp;
        }


        public String PostData() {
        Boolean s = false;
        HttpParams params = new BasicHttpParams();
        params.setParameter(CoreProtocolPNames.PROTOCOL_VERSION,
                HttpVersion.HTTP_1_1);
        HttpClient httpClient = new DefaultHttpClient(params);
        String url = "http://localhost:8080" +"/get_xml_data?id=" + 1;
        System.out.println("url----------" + url);
        HttpPost httpPost = new HttpPost(url);
        HttpResponse httpResponse = null;
        try {
            httpResponse = httpClient.execute(httpPost);
        } catch (IOException e) {
            e.printStackTrace();
        }
        HttpEntity httpEntity = httpResponse.getEntity();
        String token = readResponse(httpResponse);
        return token;
    }

这里MyAsyncTask是计时器任务中的计划，每15分钟后调用一次。如何在类外调用此MyAsyncTask调用，而不会影响计划的计时器任务。我没有将MyAsyncTask类设为静态。