Sending 50+ messages causing issues lead to generic failure

Question

I am developing an application in which i need to send 100+ of messages. After going through few threads i came to know there is limitation on sending messages like 100 messages can be send in an hour. To do so i divide my recipient list into chunks and place delay of 5 seconds between each chunk and 3 seconds delay in every message. The delay between chunks increase after every chunk and when it gets to 100 seconds it will reset to 5 seconds. After that it worked OK for 50 messages but when i raise recipient list it causing issues some messages didn't go at first place and shown as error messages in native.

Is there any standard way to achieve this i may need to send 100+ messages , how can i send multiple messages without any failure at once. If i need to place delay what should be the appropriate delay between chunks or messages.

Thanks in advance.

private final int MAX_SMS_IN_ONE_TIME = 10;
private final int DELAY_BETWEEN_CHUNKS = 5000;

public void sendMessage(arguments){ 
    // Send long messages in chunk of 20 messages and put gap of increasing 5 seconds till 50 seconds and then reset.

    final Iterator iterator = messageChunks.iterator();
    new Thread(new Runnable() {
        @Override
        public void run(){

        int interval =1;
        while (iterator.hasNext()) {

            for (final Contact contact :
                (List<Contact>) iterator.next()) {

                sendSMS(body, contact.getmMobileNumbers().get(0));

                App.trackEvent("Message", "Sent", "Messages from our sms app");
            }
        }
        try {
            Log.i("chunk", "chunk # " + interval + " delay is " + DELAY_BETWEEN_CHUNKS);
            Thread.sleep(DELAY_BETWEEN_CHUNKS * interval);
            interval++;
            if (interval == 10) {
                interval = 1;
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        }
        }
    }).start();
}

public void sendSMS(final String message, final String phoneNo) {
    try {
        String SENT = "com.ebryx.smscustommessagegeneration"+""+System.currentTimeMillis()+""+((int)this.getmMessageId());
        Intent intentMessageASendStatus = new Intent(SENT);

        final PendingIntent pi = PendingIntent.getBroadcast(App.getContext(),  ((int)this.getmMessageId()),
                intentMessageASendStatus, PendingIntent.FLAG_CANCEL_CURRENT);
        final ArrayList<PendingIntent> sentPI = new ArrayList<PendingIntent>(){{add(pi);}};

        App.getContext().registerReceiver(new BroadcastReceiver(){
            @Override
            public void onReceive(Context arg0, Intent arg1) {


                switch (getResultCode())
                {
                    case Activity.RESULT_OK:

                        Log.i("tag","sent successfully ");
            break;
                    case SmsManager.RESULT_ERROR_GENERIC_FAILURE:

                        Log.i("tag","Generic Failure");
                break;

                    case SmsManager.RESULT_ERROR_NO_SERVICE:

                        Log.i("tag","No service failure");
            break;

        case SmsManager.RESULT_ERROR_NULL_PDU:
                        break;
                    case SmsManager.RESULT_ERROR_RADIO_OFF:

                        Log.i("tag","Airplane mode failure");
                        break;
                }
            }
        }, new IntentFilter(SENT));

        final SmsManager smsManager = SmsManager.getDefault();
        final ArrayList<String> parts = smsManager.divideMessage(message);

        new Timer().schedule(new TimerTask() {
                @Override
                public void run() {
                    smsManager.sendMultipartTextMessage(phoneNo, null, parts, sentPI, null);

                }}, 3000);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Answer 1

You should use two broadcast receiver with pending intent for SENT and DELIVER.

After message delivers you have to add callback mechanism to notify msg has been delivered and stat sending new message. This call should be synchronized.

1. Create a HashMap, and send to below method one by one according to status of delivery which we are getting in below delivery broadcast receiver.

       /**
        * Sends an SMS message to another device
        * 
        * @param phoneNumber Number to which msg send
        * @param message Text message
        */
   private void sendSMS(String phoneNumber, String message) {
       // Intent Filter Tags for SMS SEND and DELIVER
       String SENT = "SMS_SENT";
       String DELIVERED = "SMS_DELIVERED";
   // STEP-1___
       // SEND PendingIntent
       PendingIntent sentPI = PendingIntent.getBroadcast(this, 0, new Intent(
               SENT), 0);
   
       // DELIVER PendingIntent
       PendingIntent deliveredPI = PendingIntent.getBroadcast(this, 0,
               new Intent(DELIVERED), 0);
   // STEP-2___
       // SEND BroadcastReceiver
       BroadcastReceiver sendSMS = new BroadcastReceiver() {
           @Override
           public void onReceive(Context arg0, Intent arg1) {
               switch (getResultCode()) {
               case Activity.RESULT_OK:
                   Toast.makeText(getBaseContext(), "SMS sent",
                           Toast.LENGTH_SHORT).show();
                   break;
               case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                   Toast.makeText(getBaseContext(), "Generic failure",
                           Toast.LENGTH_SHORT).show();
                   break;
               case SmsManager.RESULT_ERROR_NO_SERVICE:
                   Toast.makeText(getBaseContext(), "No service",
                           Toast.LENGTH_SHORT).show();
                   break;
               case SmsManager.RESULT_ERROR_NULL_PDU:
                   Toast.makeText(getBaseContext(), "Null PDU",
                           Toast.LENGTH_SHORT).show();
                   break;
               case SmsManager.RESULT_ERROR_RADIO_OFF:
                   Toast.makeText(getBaseContext(), "Radio off",                            Toast.LENGTH_SHORT).show();
                   break;
               }
           }
       };
   
       // DELIVERY BroadcastReceiver
       BroadcastReceiver deliverSMS = new BroadcastReceiver() {
           @Override
           public void onReceive(Context arg0, Intent arg1) {
               switch (getResultCode()) {
               case Activity.RESULT_OK:
                    // TODO : notify from here to send new message.
                    // Add callback mechanism 
                   Toast.makeText(getBaseContext(), "SMS delivered",
                           Toast.LENGTH_SHORT).show();
                   break;
               case Activity.RESULT_CANCELED:
                   Toast.makeText(getBaseContext(), "SMS not delivered",
                           Toast.LENGTH_SHORT).show();
                   break;
               }
           }
       };
   // STEP-3___
       // ---Notify when the SMS has been sent---
       registerReceiver(sendSMS, new IntentFilter(SENT));
   
       // ---Notify when the SMS has been delivered---
       registerReceiver(deliverSMS, new IntentFilter(DELIVERED));
   
       SmsManager sms = SmsManager.getDefault();
       sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI);
    }
   }
   

2. You can also remove elements from your HashMap as your SMS DELIVERED This could be helpful for you to track how many messages are delivered successfully.