Java Development

[klerisson]

Greetings!

Not sure what kind of problem I facing, but still quite interesting.

I have an UiApplication which start a thread to listen for incoming SMS and automatically answer them. This same class implements PhoneListener as bellow:

public class SMSSenderReceiver extends Thread implements PhoneListener {

	private static DatagramConnection _dc;
	private static int _callIdIncoming;
	private static int _callIdAnswered;
	public static String _phoneNumber;
	
	static {
	try {
		_dc = (DatagramConnection) Connector.open("sms://");
		} catch (IOException e) {
			System.out.println(e);
		}
	}

	public SMSSenderReceiver() {
		super();
		_callIdIncoming = -1;
		_callIdAnswered = -1;
		Phone.addPhoneListener(this);
	}

	public void run() {
		try {
			for (;;) {
				Datagram d = _dc.newDatagram(_dc.getMaximumLength());
				_dc.receive(d);
				String address = d.getAddress();
				if (address.startsWith("//")) {
					address = address.substring(2);
				}
				String answer = getResponseByPhone(address);
				if (answer != null) {
					answer.getBytes();
					Datagram returnpacket = _dc.newDatagram(_dc
							.getMaximumLength());
					returnpacket.setAddress(d.getAddress());
					returnpacket.setData(answer.getBytes(), 0, answer.length());
					_dc.send(returnpacket);
				}
			}
		} catch (IOException ioe) {
			System.out.println(ioe);
			Phone.removePhoneListener(this);
		}
	}

	private static String getResponseByPhone(final String phone) {
		TextResponses tr = TextResponses.getInstance();
		MultiMap mm = tr.getResponses();
		Enumeration valuesEnum = mm.keys();
		while (valuesEnum.hasMoreElements()) {
			String element = valuesEnum.nextElement().toString();
			if (mm.containsValue(element, phone)) {
				return element;
			} else {
				continue;
			}
		}
		return null;
	}

	//	public void missedCallSMSSender(final String address) {
	//		try {
	//			if(_callIdAnswered != _callIdIncoming){
	//				//				if (address.startsWith("//")) {
	//				//					address = address.substring(2);
	//				//				}
	//				String answer = this.getResponseByPhone(address);
	//				if (answer != null) {
	//					answer.getBytes();
	//					Datagram returnpacket = _dc.newDatagram(_dc
	//							.getMaximumLength());
	//					returnpacket.setAddress("//" + address);
	//					returnpacket.setData(answer.getBytes(), 0, answer
	//							.length());
	//					_dc.send(returnpacket);
	//				}
	//				_callIdAnswered = _callIdIncoming = -1;
	//				//_phoneCallsHash.remove("" + _callIdIncoming);
	//			}
	//		} catch (Exception e) {
	//			System.out.println(e);
	//		}
	//	}

	public void callIncoming(final int callId) {
		if(_callIdIncoming != callId){
			UiApplication.getUiApplication().invokeLater(new Runnable(){
				public void run() {
					_callIdIncoming = callId;
					PhoneCall phoneCall = Phone.getCall( callId );
					_phoneNumber = null;
					try {
						_phoneNumber = phoneCall.getDisplayPhoneNumber();

						String tempNumber = null;
						for(int i = _phoneNumber.length() -1 ;i >= 0; --i) {
							if(Character.isDigit(_phoneNumber.charAt(i))){
								tempNumber = _phoneNumber.charAt(i) + ((tempNumber == null) ? "" : tempNumber) ;
							}
						}
						_phoneNumber = tempNumber;

						System.out.println("**bleep** Phone Number: " + _phoneNumber);
					} catch(NullPointerException npe) {
						_phoneNumber = "0";
						System.out.println("NULL!!!!" + npe);
					}
				}
			});
		}
	}

	public void callAnswered(int callId) {
		_callIdAnswered = callId;
	}

	public void callDisconnected(int callId) {
		UiApplication.getUiApplication().invokeLater(new Runnable(){
			public void run() {
				//System.out.println("**bleep** Phone Number: " + _phoneNumber);
				//SMSSenderReceiver.this.missedCallSMSSender(_phoneNumber);
				String address = _phoneNumber;
				if(_callIdAnswered != _callIdIncoming){
					//					if (address.startsWith("//")) {
					//						address = address.substring(2);
					//					}
					String answer = getResponseByPhone(address);
					if (answer != null) {
						answer.getBytes();
						try {
							Datagram returnpacket = _dc.newDatagram(_dc.getMaximumLength());
							returnpacket.setAddress("//" + address);
							returnpacket.setData(answer.getBytes(), 0, answer
									.length());
							_dc.send(returnpacket);
						} catch(Exception e) {
							System.out.println(e);
						}
					}
					_callIdAnswered = _callIdIncoming = -1;
				}
			}
		});
	}
...

The goal is to send a SMS for each missed call. So, on incomingCall I catch the call Id and the phone number assign them to the static variables. If the call is answered I catch the call id also. Once the the call is disconnected I just check the call answered id and incoming id in case they differ from each other I got a miss call and I have to send a SMS.

The problem is once the callDisconneted is called I no longer have the _phoneNumber value. On incomingCall I able to see the number, but not after all. Why? Seems to be a basic fundamental about multi-thread.

Does anybody know what is happening?

Thanks in advance!

--

[RexDoug · Accepted solution]

This issue probably has to do with the fact that the call listener is actually coming into your code on the phone application thread. Each application gets a separate copy of static context. Consequently, you will not see the same data when you access this variable in your own application process.

You probably have two choices here: (a) send yourself a global event form the call listener, then pick up this event in your own process, or (b) use the runtime store to retain the value so that both processes can *see* it.