Передача контекста из asynctask?

Question

Итак, у меня есть класс службы задач, который запускает асинтезу, а затем запускает уведомление, если условие выполнено. В методе sendnotification, где создается Intent, существует исключение нулевого указателя, контекст имеет все нулевые значения. Я не думаю, что правильно передаю контекст из асинтезы BloodLevelParse? Не уверен, что еще я могу попробовать. Вот класс:

public class TaskService extends IntentService { 

    private ArrayList<BloodLevels> BloodLevelList; 

    private String bloodLevel; 
    private String bloodType; 
    private Integer bloodLevelDays; 

    private MyProfileActivity myProfileActivity; 

    private BloodLevelParse bloodLevelParse; 

    public TaskService() { 
     super("TaskService"); 
    } 

    @Override 
    protected void onHandleIntent(Intent intent) { 

     // Pass through the blood type 
     Bundle bundle = intent.getExtras(); 
     bloodType = bundle.getString("currentBloodType2"); 

     // Only perform check if there is an internet connection 
     if (CheckNetwork.isInternetAvailable(TaskService.this)) { 

      // Check the current blood level for the given blood type 
      new BloodLevelParse(this).execute(bloodType); 

     } else { 
      Toast.makeText(
        TaskService.this, 
        "Unable to perform daily blood level check, no internet connection.", 
        Toast.LENGTH_LONG).show(); 
     } 

    } 

    private void sendNotification(Context context) { 

     NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
       this).setSmallIcon(R.drawable.ic_launcher) 
       .setContentTitle("Blood Level Notification") 
       .setContentText(bloodLevel); 

     Intent resultIntent = new Intent(this, MyProfileActivity.class); 

     // Because clicking the notification opens a new ("special") activity, 
     // there's no need to create an artificial back stack. 
     PendingIntent resultPendingIntent = PendingIntent.getActivity(this, 0, 
       resultIntent, PendingIntent.FLAG_UPDATE_CURRENT); 

     mBuilder.setContentIntent(resultPendingIntent); 

     // Sets an ID for the notification 
     int mNotificationId = 001; 
     // Gets an instance of the NotificationManager service 
     NotificationManager mNotifyMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); 
     // Builds the notification and issues it. 
     mNotifyMgr.notify(mNotificationId, mBuilder.build()); 

    } 

    public class BloodLevelParse extends 
      AsyncTask<String, Void, ArrayList<BloodLevels>> { 

     private Context myCtx; 

     public BloodLevelParse(Context ctx){ 
      // Now set context 
      this.myCtx = ctx; 
     } 

     protected ArrayList<BloodLevels> doInBackground(String... params) { 

      String bloodType = params[0]; 

      try { 

       // HTTP PROTOCOL 
       Document doc = Jsoup 
         .connect(
           "http://www.giveblood.ie/Current_Blood_Supply/") 
         .timeout(5000) 
         .userAgent(
           "Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6") 
         .cookie("auth", "token").get(); 

       // EXTRACT SPECIFIC ELEMENTS FROM THE HTML 
       Elements bloodsupplylines1 = doc.select("td.bloodsupplyline"); 
       Elements bloodsupplylines2 = bloodsupplylines1 
         .select("img[src~=(?i)\\.(png|jpe?g|gif)]"); 

       // CREATE LIST AND POPULATE IT WITH ELEMENTS RETRIEVE FROM HTML 
       List<String> BloodLevelRawList = new ArrayList<String>(); 

       for (Element bloodsupplyline : bloodsupplylines2) { 

        BloodLevelRawList.add(new String(bloodsupplyline 
          .attr("alt"))); 

       } 

       BloodLevelList = new ArrayList<BloodLevels>(); 

       for (int i = 0; i < BloodLevelRawList.size(); i += 2) { 
        // Only add to BloodLevelList if it is the blood type 
        // selected 
        if (BloodLevelRawList.get(i).equals(bloodType)) { 

         BloodLevelList.add(new BloodLevels(BloodLevelRawList 
           .get(i), BloodLevelRawList.get(i + 1))); 
        } 
       } 

      } 

      catch (IOException ioex) { 
       ioex.printStackTrace(); 
      } 

      return BloodLevelList; 

     } 

     @Override 
     protected void onPostExecute(ArrayList<BloodLevels> BloodLevelList) { 

      String bloodLevelReplace = BloodLevelList.get(0).getBloodLevel() 
        .replaceAll("Blood supply", ""); 

      bloodLevel = ("Current blood levels for " 
        + BloodLevelList.get(0).getBloodType() + " is" + bloodLevelReplace); 

      // Get the number of days from the blood level string 
      Scanner in = new Scanner(bloodLevel).useDelimiter("[^0-9]+"); 
      int bloodLevelDays = in.nextInt(); 

      // Send notification if no. of days blood level supply goes below 5 
      if (bloodLevelDays < 5) { 

       TaskService taskService = new TaskService(); 
       taskService.sendNotification(myCtx); 
      } 

     } 

    } 

} 

EDIT: В соответствии с ответом tyczj, я не нуждался в AsyncTask, глупый меня. Вот рабочая версия:

public class TaskService extends IntentService { 

private ArrayList<BloodLevels> BloodLevelList; 

private String bloodLevel; 
private String bloodType; 
private Integer bloodLevelDays; 

public TaskService() { 
    super("TaskService"); 
} 

@Override 
protected void onHandleIntent(Intent intent) { 

    // Pass through the blood type from AlarmReceiver 
    Bundle bundle = intent.getExtras(); 
    bloodType = bundle.getString("currentBloodType2"); 

    // Only perform check if there is an internet connection 
    if (CheckNetwork.isInternetAvailable(TaskService.this)) { 

     try { 

      // HTTP PROTOCOL 
      Document doc = Jsoup 
        .connect(
          "http://www.giveblood.ie/Current_Blood_Supply/") 
        .timeout(5000) 
        .userAgent(
          "Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6") 
        .cookie("auth", "token").get(); 

      // EXTRACT SPECIFIC ELEMENTS FROM THE HTML 
      Elements bloodsupplylines1 = doc.select("td.bloodsupplyline"); 
      Elements bloodsupplylines2 = bloodsupplylines1 
        .select("img[src~=(?i)\\.(png|jpe?g|gif)]"); 

      // CREATE LIST AND POPULATE IT WITH ELEMENTS RETRIEVE FROM HTML 
      List<String> BloodLevelRawList = new ArrayList<String>(); 

      for (Element bloodsupplyline : bloodsupplylines2) { 

       BloodLevelRawList.add(new String(bloodsupplyline 
         .attr("alt"))); 

      } 

      BloodLevelList = new ArrayList<BloodLevels>(); 

      for (int i = 0; i < BloodLevelRawList.size(); i += 2) { 
       // Only add to BloodLevelList if it is the blood type 
       // selected 
       if (BloodLevelRawList.get(i).equals(bloodType)) { 

        BloodLevelList.add(new BloodLevels(BloodLevelRawList 
          .get(i), BloodLevelRawList.get(i + 1))); 
       } 
      } 

     } 

     catch (IOException ioex) { 
      ioex.printStackTrace(); 
     } 

     String bloodLevelReplace = BloodLevelList.get(0).getBloodLevel() 
       .replaceAll("Blood supply", ""); 

     bloodLevel = ("Current blood levels for " 
       + BloodLevelList.get(0).getBloodType() + " is" + bloodLevelReplace); 

     // Get the number of days from the blood level string 
     Scanner in = new Scanner(bloodLevel).useDelimiter("[^0-9]+"); 
     int bloodLevelDays = in.nextInt(); 

     // Send notification if no. of days blood level supply goes below 5 
     if (bloodLevelDays < 5) { 

      this.sendNotification(this); 

     } 

    } else { 
     Toast.makeText(
       TaskService.this, 
       "Unable to perform daily blood level check, no internet connection.", 
       Toast.LENGTH_LONG).show(); 
    } 

} 

private void sendNotification(Context context) { 

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
      this).setSmallIcon(R.drawable.ic_launcher) 
      .setContentTitle("Blood Level Notification") 
      .setContentText(bloodLevel); 

    Intent resultIntent = new Intent(this, MyProfileActivity.class); 

    // Because clicking the notification opens a new ("special") activity, 
    // there's no need to create an artificial back stack. 
    PendingIntent resultPendingIntent = PendingIntent.getActivity(this, 0, 
      resultIntent, PendingIntent.FLAG_UPDATE_CURRENT); 

    mBuilder.setContentIntent(resultPendingIntent); 

    // Sets an ID for the notification 
    int mNotificationId = 001; 
    // Gets an instance of the NotificationManager service 
    NotificationManager mNotifyMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); 
    // Builds the notification and issues it. 
    mNotifyMgr.notify(mNotificationId, mBuilder.build()); 

} 

}

Answer 1

для одного, почему вы используете в качестве IntentService в AsyncTask? IntentService уже работает на отдельном потоке, поэтому использование AsyncTask не является неотделимым.

также поскольку IntentService является Context из которой можно вывести все, что вам нужно сделать, это вызов TaskService.this и у вас есть Context