Question

I am learning how to send SMS in android, have seen the code as below:

public class SMSReceiver extends BroadcastReceiver
{
   @Override
   public void onReceive(Context context, Intent intent)
   {
   //---get the SMS message passed in---
   Bundle bundle = intent.getExtras();
   SmsMessage[] msgs = null;
   String str = “”;
   if (bundle != null)
   {
      //---retrieve the SMS message received---
      Object[] pdus = (Object[]) bundle.get(“pdus”);
      msgs = new SmsMessage[pdus.length];
      for (int i=0; i<msgs.length; i++){
         msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]);
         str += “SMS from “ + msgs[i].getOriginatingAddress();
         str += “ :”;
         str += msgs[i].getMessageBody().toString();
         str += “\n”;
   }
    //---display the new SMS message---
   Toast.makeText(context, str, Toast.LENGTH_SHORT).show();
  }
  }
}

Now my question is how do I know what are the contents of Intent object that are passed into onReceive function? As below:

Object[] pdus = (Object[]) bundle.get(“pdus”);

How do I know there is a “pdus” key in the bundle object?
I can’t find any clue in the API doc, anyone know where is the related information located?

I don’t only want to know what the SMS intent pass into onReceive function, but also the other system related Intent, but I can’t locate any related information in the API doc. I wonder does the information really exist?

Answer 1

You can check if the bundle contains a Key value pair with key pdus using bundle.containsKey("pdus") which returns true if there are any Protocol Data Units (PDUs which in your case are SMSes).

So, the check for processing the PDUs should be if (bundle != null && bundle.containsKey("pdus"))