Java android 意图服务只工作一次

Question

我想创建一个意图服务，它在整个应用程序中（在所有 activity 中）都有时间段并执行任务。我使用 Handler 。我在 activity 开始了一项服务。我看到只有一次服务工作（执行任务）为什么？这是我的服务：

public class SenderXML extends Service {

    public static boolean running = false;
    private Timer timer = new Timer();
    private SendXMLTask sendXMLTask;
    private Context context;

    static String convertStreamToString(java.io.InputStream is) {
        java.util.Scanner s = new java.util.Scanner(is).useDelimiter("\A");
        return s.hasNext() ? s.next() : "";
    }

    @Override
    public void onCreate() {
        super.onCreate();
        context = getApplicationContext();
        Gson gson = new Gson();
        MainActivity.xmlList = null;
        MainActivity.xmlList = new ArrayList<>();
        SharedPreferences sharedPref = getApplicationContext().getSharedPreferences("TAG", Context.MODE_PRIVATE);
        List<String> productFromShared1 = new ArrayList<>();
        String jsonPreferences1 = sharedPref.getString("TAG1", "");

        Type type1 = new TypeToken<List<String>>() {
        }.getType();
        productFromShared1 = gson.fromJson(jsonPreferences1, type1);
        if (productFromShared1 != null)
            MainActivity.xmlList.addAll(productFromShared1);
        Log.e("tworzenie serwisu ", "tworzenie");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e("Dziełanie serwisu ", "Dziełanie");
        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {

            @Override
            public void run() {
                Log.e("Dziełanie serwisu 1111", "Dziełanie 111");
                if (!MainActivity.xmlList.isEmpty()) {
                    if (NetworkUtil.isNetworkAvailable(context)) {
                        if (!running) {
                            sendXMLTask = new SendXMLTask();
                            sendXMLTask.execute();
                        }
                    }
                }
            }
        }, 1000 * 60 * 2);

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        if (running) {
            timer.cancel();
            sendXMLTask = new SendXMLTask();
            sendXMLTask.cancel(true);
            running = false;
        }
        Log.e("service ", "nie działa");
        super.onDestroy();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    class SendXMLTask extends AsyncTask<Void, Void, String> {

        @Override
        protected String doInBackground(Void... voids) {
            Log.e("xml ", MainActivity.xmlList.size() +"");
            running = true;
            HttpClient httpclient = HttpClientUtil.getHttpClient(getApplicationContext());
            HttpPost httppost = new HttpPost(Util.getServerUrl(getApplicationContext()) + "/SetData");
            ArrayList<NameValuePair> namevaluepairs = new ArrayList<>(2);
            namevaluepairs.add(new BasicNameValuePair("token", String.valueOf(E_Gps.TOKEN)));
            namevaluepairs.add(new BasicNameValuePair("xml", MainActivity.xmlList.get(0)));
            if (MainActivity.xmlList.size() > 0) {
                MainActivity.btTransfer.setBackgroundColor(Color.YELLOW);
            }
            try {
                httppost.setEntity(new UrlEncodedFormEntity(namevaluepairs));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            HttpResponse response = null;
            try {
                response = httpclient.execute(httppost);
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
            InputStream responseInputStream = null;
            try {
                responseInputStream = new BufferedInputStream(response.getEntity().getContent());
                try {
                    int tt = ResponseParser.getResponseType(responseInputStream);
                    if (tt == 0) {
                        return null;
                    }
                } catch (EmptyResponseException | UnknownAnswerName | XmlPullParserException e) {
                    e.printStackTrace();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            Log.e("xml", MainActivity.xmlList.get(0));
            Log.e("xml wys ", convertStreamToString(responseInputStream));
            return convertStreamToString(responseInputStream);
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if (s != null) {
                MainActivity.xmlList.remove(0);
                Gson gson = new Gson();
                String jsonCurProduct = gson.toJson(MainActivity.xmlList);
                SharedPreferences sharedPref = getApplicationContext().getSharedPreferences("TAG", Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = sharedPref.edit();
                editor.putString("TAG1", jsonCurProduct);
                editor.apply();
            }
            if (!MainActivity.xmlList.isEmpty()) {
                sendXMLTask = new SendXMLTask();
                sendXMLTask.execute();
            } else {
                MainActivity.btTransfer.setBackgroundColor(Color.GREEN);
            }
            running = false;
        }
    }
}

Answer 1

您是否尝试过使用警报管理器定期启动您的 Intent 服务？如果您还没有尝试过，可以按照此 link 进行操作 Alarm Manager Example

您可以使用警报管理器定期启动您的 Intent 服务。

Answer 2

当您在 Activity 中调用 startService() 时，将创建 Service（如果它尚不存在）并调用 onStartCommand()。除非您再次调用 startService()，否则不会再次调用 onStartCommand()。

由于您是在 onStartCommand() 中发布 Runnable，您应该让 Runnable 在一段时间后将自己重新发布到运行（如果您想要这到运行连续）。

确保在用完后停止 Service。

Java android 意图服务只工作一次

Java android intent service works only one time

java

android

android-intent

android-service