WIP: Broadcast messages in application layer

In the current WIP status: Prepares creation of a BroadcastMessage class which will not have any specific recipients by making Message abstract and creating a subclass OneToOneMessage. Rest of the code is just dealing with the interface changes.

src/applications/PingApplication.java

@@ -11,6 +11,7 @@ import report.PingAppReporter;
 import core.Application;
 import core.DTNHost;
 import core.Message;
+import core.OneToOneMessage;
 import core.Settings;
 import core.SimClock;
 import core.SimScenario;
@@ -123,10 +124,10 @@ public class PingApplication extends Application {
 		if (type==null) return msg; // Not a ping/pong message
 
 		// Respond with pong if we're the recipient
-		if (msg.getTo()==host && type.equalsIgnoreCase("ping")) {
+		if (msg.isFinalRecipient(host) && type.equalsIgnoreCase("ping")) {
 			String id = "pong" + SimClock.getIntTime() + "-" +
 				host.getAddress();
-			Message m = new Message(host, msg.getFrom(), id, getPongSize());
+			Message m = new OneToOneMessage(host, msg.getFrom(), id, getPongSize());
 			m.addProperty("type", "pong");
 			m.setAppID(APP_ID);
 			host.createNewMessage(m);
@@ -137,7 +138,7 @@ public class PingApplication extends Application {
 		}
 
 		// Received a pong reply
-		if (msg.getTo()==host && type.equalsIgnoreCase("pong")) {
+		if (msg.isFinalRecipient(host) && type.equalsIgnoreCase("pong")) {
 			// Send event to listeners
 			super.sendEventToListeners("GotPong", null, host);
 		}
@@ -176,7 +177,7 @@ public class PingApplication extends Application {
 		double curTime = SimClock.getTime();
 		if (curTime - this.lastPing >= this.interval) {
 			// Time to send a new ping
-			Message m = new Message(host, randomHost(), "ping" +
+			Message m = new OneToOneMessage(host, randomHost(), "ping" +
 					SimClock.getIntTime() + "-" + host.getAddress(),
 					getPingSize());
 			m.addProperty("type", "ping");