StopService onDestroy被調用，但服務沒有結束

Question

我嘗試使用TimerTask從服務器api下載數據，任務在後臺應用程序中循環。

我有一個服務類：

public class RequestNewInvoice extends Service { 

    private Timer timer; 
    private CheckTask checkTask; 
    private Handler handler; 
    private JSONParser jsonParser; 
    private JSONObject jsonObject; 
    private boolean startService = true; 

    private void init(){  
     this.handler = new Handler(new Handler.Callback() { 
      @Override 
      public boolean handleMessage(Message msg) { 
       Log.e("Message: ",msg.obj+""); 
       return false; 
      } 
     }); 

     this.timer = new Timer(); 
     this.checkTask = new CheckTask(); 
     this.startService = true; 
     timer.scheduleAtFixedRate(checkTask, 5000, 20 * 1000); 
    } 

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

    @Override 
    public int onStartCommand(final Intent intent, int flags, final int startId) { 
     init(); 
     return START_STICKY; 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     Log.e("SERVICE STOP", "true"); 
     startService = false; 
     checkTask.cancel(); 
     timer.cancel(); 
     timer.purge(); 
    } 

    private class CheckTask extends TimerTask{ 
     @Override 
     public void run() { 
      funcCheckInvoice(); 
     } 
    } 

    public void funcCheckInvoice(){ 
     try{ 
      if(startService){    
       Log.e("SERVICE START", "true"); 
       HttpParams httpParameters = new BasicHttpParams(); 
       HttpConnectionParams.setConnectionTimeout(httpParameters, SuperVAR.GET_CURRENT_SHIPMENT_TIMEOUT); 
       HttpConnectionParams.setSoTimeout(httpParameters, SuperVAR.GET_CURRENT_SHIPMENT_TIMEOUT); 

       httpClient = new DefaultHttpClient(httpParameters); 
       HttpGet httpGet = new HttpGet(SuperVAR.URL_GET_LIST_INVOICE_IN_CURRENT_SHIPMENT+"?"+ URLEncodedUtils.format(_REQUEST, "utf-8")+"unused="+System.currentTimeMillis()/1000); 

       httpGet.setHeader("token",token); 
       httpGet.setHeader("Cache-Control","no-cache"); 
       httpGet.setHeader("Cache-Control","no-store"); 

       HttpResponse httpResponse = httpClient.execute(httpGet); 
       HttpEntity httpEntity = httpResponse.getEntity(); 
       jsonObject = jsonParser.getJSONFromRESPONSE(httpEntity); 


       if(jsonObject == null){ 
         Message message = Message.obtain(); 
         message.obj = "get null.... internet like shit T_T"; 
         handler.sendMessage(message); 
       }else { 
         Message message = Message.obtain(); 
         message.obj = "download ok"; 
         handler.sendMessage(message); 
       } 
      }else { 
       Log.e("SERVICE START", "false"); 
       return; 
      } 
     }catch (Exception e){ 
      e.printStackTrace(); 
     } 
    } 
} 

當我在活動課運行stopService，服務調用的onDestroy功能，但仍定時器生活在。

如何銷燬計時器任務？

Answer 1

使用處理器和銷燬刪除回調任務

TimerTask scanTask; 
    final Handler handler = new Handler(); 
    Timer t = new Timer(); 

    scanTask = new TimerTask() { 
     public void run() { 
      handler.post(task); 
     }}; 
    t.schedule(scanTask, 5000, 20 * 1000); 

    Runnable task = new Runnable() { 
    @Override 
    public void run() { 
      //START YOUR JOB 
      (new FetchData()).execute(); 

    } 
}; 





@Override 
public void onDestroy() { 
    super.onDestroy(); 
    Log.e("SERVICE STOP", "true"); 
    startService = false; 
    checkTask.cancel(); 
    timer.cancel(); 
    timer.purge(); 
    handler.removeCallbacks(task); 

} 

public class FetchData extends AsyncTask<Void, Void, Void> 
{ 
    @Override 
    protected Void doInBackground(Void... params) 
    { 
      funcCheckInvoice(); 
    } 
} 

Answer 2

你已經開始你的服務作爲START_STICKY這可能是你爲什麼 你不能停止服務。

以下是START_STICKY的definition。

不斷從onStartCommand（意向，INT，INT）返回：如果當它開始這個 服務的進程被終止（從 onStartCommand（意向，INT，INT）回國後），然後把它留在開始狀態 但不保留此交付的意圖。稍後系統會嘗試 重新創建服務。由於它處於啓動狀態，因此 保證在創建 新服務實例後調用onStartCommand（Intent，int，int）;如果沒有任何掛起的啓動命令將 傳送到服務中，則將以空對象 對象調用它，因此您必須小心檢查此操作。

該模式對於明確開始的事物以及 停止運行任意時間段（例如執行背景音樂播放的服務 ）有意義。使用START_NOT_STICKY

嘗試，你也需要改變你呼籲取消爲您呼叫 scheduleAtFixedRate的方式。

private ScheduledThreadPoolExecutor scheduleTaskExecutor; 
private ScheduledFuture schedule; 
... 
scheduleTaskExecutor = (ScheduledThreadPoolExecutor) Executors.newScheduledThreadPool(5); 
schedule = scheduleTaskExecutor.scheduleAtFixedRate(checkTask, 5000, 20 * 1000); 


@Override 
public void onDestroy() 
{ 
    super.onDestroy(); 
    startService = false; 
    checkTask.cancel(); 

    schedule.cancel(true); 

}