MessageManager.java

/*
 * class MESSAGEMANAGER
 * Controls message queues
*/

// For BlockingQueue, ArrayBlockingQueue
import java.util.concurrent.*;

public class MessageManager {

 private Connection _connection;
 
 private User user; // Person using program
 private User partner; // Interlocutor

 private BlockingQueue<Message> inbox;
 private BlockingQueue<Message> outbox;

 private boolean incomingSignal = false;
 private boolean outgoingSignal = false;

 public MessageManager() {
 user = new User();
 partner = new User ();

 inbox = new ArrayBlockingQueue(20);
 outbox = new ArrayBlockingQueue(20);
 }

 public void setConnection(Connection connection) {
 _connection = connection;
 }

 public User getUser() {
 return user;
 }

 public User getPartner() {
 return partner;
 }

 public void sendMessage(String msgContent) {
	 //int senderID = user.getID();
	 //int receiverID = partner.getID();
 int senderID = 1;
 int receiverID = 2; // just for testing
	 long timestamp = System.currentTimeMillis() / 1000L;

 // Create new Message instance
 Message msgObject = new Message(
			 msgContent, senderID, receiverID, senderID);

 try {
 outbox.put(msgObject);
 } catch (InterruptedException e) {
 System.out.println(e);
 }
 outboxNotify();
 }

 public void displayMessage(Message incomingMsg) {
 try {
 inbox.put(incomingMsg);
 } catch (InterruptedException e) {
 System.out.println(e);
 }
 inboxNotify();
 }

 public Message getOutboxMessage(){
 try {
 return outbox.take();
 } catch (InterruptedException e) {
 System.out.println(e);
 return null;
 }
 }

 // Source: http://tutorials.jenkov.com/java-concurrency/thread-signaling.html#spuriouswakeups
 // Protected against missed signals and spurious wakeups
 // Technically unsafe to swallow InterruptedException:
 // http://www.ibm.com/developerworks/java/library/j-jtp05236/index.html
 public void outboxWait() {
 synchronized(outbox) {
 while (!outgoingSignal) {
 try {
 outbox.wait();
 } catch (InterruptedException e) {
 System.out.println(e);
 }
 }
 }
 }

 public void outboxNotify() {
 synchronized(outbox) {
 outgoingSignal = true;
 outbox.notify();
 }
 }

 public Message getInboxMessage(){
 try {
 return inbox.take();
 } catch (InterruptedException e) {
 System.out.println(e);
 return null;
 }
 }


 public void inboxWait() {
 synchronized(inbox) {
 while (!incomingSignal) {
 try {
 inbox.wait();
 } catch (InterruptedException e) {
 System.out.println(e);
 }
 }
 }
 }

 public void inboxNotify() {
 synchronized(inbox) {
 incomingSignal = true;
 inbox.notify();
 }
 }
}