all may be done

week2_TinsaeGhilay/Task2/src/main/java/org/distributed/ChatHandler.java

@@ -19,11 +19,11 @@ public class ChatHandler {
     private String userId, corespondent;
     private Connection connection;
     private Session session;
-    int status = 0; // 0: offline, 1: online
+    private final String TAG = "Task2_queue_";
+    private final String BROKER_URL = "tcp://localhost:61616";
 
     // Initialize connection and session
     public void initializeSession() throws JMSException {
-        String BROKER_URL = "tcp://localhost:61616";
         ConnectionFactory factory = new ActiveMQConnectionFactory(BROKER_URL);
         this.connection = factory.createConnection();
         this.connection.start();
@@ -67,14 +67,14 @@ public class ChatHandler {
 
     // Create producer queue for sending messages
     private MessageProducer createProducer() throws JMSException {
-        String from = "queue_" + userId;
+        String from = TAG + userId;
         Queue prod = session.createQueue(from);
         return session.createProducer(prod);
     }
 
     // Create consumer queue for receiving messages
     private MessageConsumer createConsumer() throws JMSException {
-        String to = "queue_" + getCorespondent();
+        String to = TAG+ getCorespondent();
         Queue cons = session.createQueue(to);
         return session.createConsumer(cons);
     }
@@ -105,20 +105,21 @@ public class ChatHandler {
                     Message msg = consumer.receive(300);
                     if (msg instanceof TextMessage tm) {
 
+                        String sender = tm.getStringProperty("sender");
                         // Status handling for online/offline
                         if(tm.getText().isBlank() || tm.getText().isEmpty()) {
-                            setStatus(1);
+                            System.out.println("> " + sender + " is online.");
                             continue;
                         }
                       
                         // Exit condition because correspondent went offline
                         if(tm.getText().equalsIgnoreCase("exit")) { 
-                            setStatus(0);
+                            System.out.println("> " + sender + " is offline.");
                             continue;
                         }
 
-                        // Display received message
+                        // Display received message can be from anyone
-                        String sender = tm.getStringProperty("sender");
+                        //String sender = tm.getStringProperty("sender");
                         String body = tm.getText();
                         System.out.println("[" + sender + "]: " + body);
                     }
@@ -189,18 +190,4 @@ public class ChatHandler {
         this.corespondent = corespondent;
     }
 
-    // update status of correspondent and print status message
-    private void setStatus(int status) {
-
-        // just incase of duplicate status messages, if status is same, return
-        if(this.status == status) {
-            return; 
-        }
-        this.status = status;
-        if(status == 0) {
-            System.out.println(getCorespondent()+" is now offline.");
-        } else {
-            System.out.println(getCorespondent()+" is now online.");
-        }
-    }
 }

week2_TinsaeGhilay/Task2/src/main/java/org/distributed/ChatHandler2.java

@@ -0,0 +1,242 @@
+package org.distributed;
+import java.util.Scanner;
+import javax.jms.*;
+import org.apache.activemq.ActiveMQConnectionFactory;
+
+public class ChatHandler2 {
+
+    private String userId, corespondent;
+    private Connection connection;
+    private Session senderSession, receiverSession;
+    private final String TAG = "Task2_queue_";
+    private final String BROKER_URL = "tcp://localhost:61616";
+    /**
+     * Initialize JMS session
+     * @throws JMSException
+     */
+    public void initializeSession() throws JMSException {
+        ConnectionFactory factory = new ActiveMQConnectionFactory(BROKER_URL);
+        this.connection = factory.createConnection();
+        this.connection.start();
+        this.senderSession = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
+        this.receiverSession = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
+    }
+
+    /**
+     * Start conversation loop
+     * @param sc
+     * @throws JMSException
+     */
+    public void startConversation(Scanner sc) throws JMSException {
+
+        // init receiving thread
+        Thread t = setupReceiver(userId);
+
+        // Continuous input loop
+        try {
+            while (sc.hasNextLine()){
+
+                // handle user input and send messages
+                // or if exit command, break loop
+                if(!respond(sc)){ 
+                    break;
+                }
+            }
+        } catch (Exception e) {
+            System.err.println("Error in continuous conversation: " + e.getMessage());
+        } finally {
+            t.interrupt();
+        }
+    }
+
+    /**
+     * Handle user input and send messages
+     * @param sc
+     * @throws JMSException
+     */
+    private boolean respond(Scanner sc) throws JMSException {
+        String line = sc.nextLine();
+
+        // exit condition
+        if (line.equalsIgnoreCase("exit")) {
+            System.out.println("Exiting conversation...");
+            return false;
+        }
+
+        // Send message to receiver
+        sendMessage(createProducer(corespondent), line);
+        return true;
+    }
+
+
+    // Setup producer and consumer for a receiver
+    private Thread setupReceiver(String receiver) throws JMSException {
+        MessageConsumer contact = createConsumer();
+
+        // add consumer to contacts map
+        return getThread(contact);
+    }
+
+    /**
+     * Create a producer for a given contact ID so we can send messages
+     * @param id
+     * @return MessageProducer
+     * @throws JMSException
+     */
+    private MessageProducer createProducer(String id) throws JMSException {
+        String from = TAG + id;
+        Queue prod = senderSession.createQueue(from);
+        return senderSession.createProducer(prod);
+    }
+
+
+    /**
+     * Subscribe to topics meant for this user
+     * @return MessageConsumer
+     * @throws JMSException
+     */
+    private MessageConsumer createConsumer() throws JMSException {
+        String to = TAG + userId;
+        Queue cons = receiverSession.createQueue(to);
+        return receiverSession.createConsumer(cons);
+    }
+
+    /**
+     * Send a messag
+     * @param producer
+     * @param line
+     * @throws JMSException
+     */
+    private void sendMessage(MessageProducer producer, String line) throws JMSException {
+
+        TextMessage m = senderSession.createTextMessage(line);
+        // add sender identity to message
+        m.setStringProperty("sender", userId);
+        producer.send(m);
+    }
+
+    /**
+     * Close session and connection
+     * @throws JMSException
+     */
+    public void closeSession() throws JMSException {
+        if (senderSession != null) {
+            senderSession.close();
+        }
+        if( receiverSession != null) {
+            receiverSession.close();
+        }
+        if (connection != null) {
+            connection.close();
+        }
+    }
+
+    /**
+     * Returns a thread object to handle receiving messages
+     * @param consumer
+     * @return Thread
+     */
+    private Thread getThread(MessageConsumer consumer) {
+
+        Thread receivingThread = new Thread(() -> {
+            try {
+
+                while (!Thread.currentThread().isInterrupted()) {
+
+                    // receive message with timeout
+                    Message msg = consumer.receive(100); // 100ms timeout
+                    if (msg instanceof TextMessage tm) {
+
+                        // message contents
+                        String sender = tm.getStringProperty("sender");
+                        String body = tm.getText();
+
+                        boolean isEmptyMessage = body.isBlank() || body.isEmpty();
+
+                        // display only if not blocked and not empty
+                        if (!isEmptyMessage) {
+                            System.out.println("[" + sender + "]: " + body);
+                        }
+                        
+                    }
+                }
+            } catch (javax.jms.JMSException e) {
+                // Silently handle interruption - normal shutdown behavior
+                if (!Thread.currentThread().isInterrupted()) {
+                    System.err.println("Error receiving message: " + e.getMessage());
+                }
+            }
+        });
+
+        
+        receivingThread.start();
+        // we are returning this so we can interrupt it later
+        return receivingThread;
+    }
+
+
+    /**
+     * Prompt for user ID
+     * @param sc
+     */
+    public void promptForUser(Scanner sc){
+
+        System.out.print("Enter your user ID: ");
+        setUserId(prompt(sc));
+        // Instructions
+        System.out.print("Welcome "+getUserId());
+        System.out.println(" -> Type 'exit' to quit.");
+    }
+
+    /**
+     * Prompt for correspondent ID
+     * @param sc
+     */
+    public void promptForCorespondent(Scanner sc){
+
+        System.out.print("Who do you want to chat with? ");
+        String contact = prompt(sc);
+        setCorespondent(contact);
+        System.out.println("You can start with: " + getCorespondent());
+    }
+
+    /**
+     * Generic prompt method prompts for whatever we need
+     * @param sc Scanner object
+     * @return String
+     */
+    private String prompt(Scanner sc) {
+
+        String user = "";
+
+        while (user.isEmpty()) {
+            try {
+                user = sc.next();
+
+            } catch (Exception e) {
+                System.err.println("Error reading correspondent ID: " + e.getMessage());
+                return null;
+            }
+        }
+        return user;
+    }
+
+    // Setters and getters
+    // user
+    public void setUserId(String userId) {
+        this.userId = userId;
+    }
+
+    public String getUserId() {
+        return userId;
+    }
+
+    // correspondent
+    public String getCorespondent() {
+        return corespondent;
+    }
+
+    public void setCorespondent(String corespondent) {
+        this.corespondent = corespondent;
+    }
+}

week2_TinsaeGhilay/Task3/src/main/java/org/distributed/ChatHandler.java

@@ -9,8 +9,7 @@ public class ChatHandler {
 
     private String userId, corespondent;
     private Connection connection;
-    private Session /*session,*/ senderSession, receiverSession;
+    private Session senderSession, receiverSession;
-    private int status = 0; // 0: offline, 1: online
     private final Map<String, MessageProducer> blocked = new ConcurrentHashMap<>();
     private final String TAG = "Task3_queue_";
     private final String BROKER_URL = "tcp://localhost:61616";
@@ -22,7 +21,6 @@ public class ChatHandler {
         ConnectionFactory factory = new ActiveMQConnectionFactory(BROKER_URL);
         this.connection = factory.createConnection();
         this.connection.start();
-        //this.session = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         this.senderSession = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         this.receiverSession = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
     }
@@ -65,17 +63,18 @@ public class ChatHandler {
         // commands to block or unblock contact
         if(line.startsWith("-")){
             delegateBlockingManagement(sc,line);
-            //return true;
+            // handling edge case where instead of user, exit comand is given
+            return !corespondent.equalsIgnoreCase("exit");
         }
 
         if (line.equalsIgnoreCase("exit")) {
             System.out.println("Exiting conversation...");
-            //return false;
+            return false;
         }
 
         // Send message to receiver
         sendMessage(createProducer(corespondent), line);
-        return !line.equalsIgnoreCase("exit");//true;
+        return true;
     }
 
 
@@ -88,8 +87,17 @@ public class ChatHandler {
 
         // block command is -b followed by contact id
         if(line.startsWith("-b")){
-            blockContact(line);
+            try {
-            promptForCorespondent(sc);
+                boolean wasCorespondent = blockContact(line);
+                // if we blocked current correspondent, prompt for new one
+                if(wasCorespondent){
+                    System.out.println("You have blocked your current correspondent. Please choose a new one.");
+                    promptForCorespondent(sc);
+                }
+            } catch (JMSException e) {
+                System.err.println(e.getMessage());
+            }
+            return;
         }
 
         // unblock command is -u followed by contact id
@@ -116,7 +124,6 @@ public class ChatHandler {
         MessageConsumer contact = createConsumer();
 
         // add consumer to contacts map
-        //contacts.put(receiver, contact);
         return getThread(contact);
     }
 
@@ -136,21 +143,32 @@ public class ChatHandler {
      * Block a contact
      * @param command
      */
-    private void blockContact(String command) {
+    private boolean blockContact(String command) throws JMSException {
         // remove the command part to get the contact id
         String contact = command.replace("-b", "").trim();
-        try {
+        if(contact.isEmpty()){
-            MessageProducer ignored = createProducer(contact);
+            throw new JMSException("No contact specified to block.");
-            // remove from contacts map
-            // and close his ass
-            if(ignored != null){
-                ignored.close();
-                blocked.put(contact, ignored);
-                System.out.println(contact + " has been blocked.");
-            }
-        } catch (JMSException e) {
-            System.err.println("Error unblocking consumer: " + e.getMessage());
         }
+        
+        boolean isCurrentCorespondent = contact.equals(getCorespondent());
+        MessageProducer ignored = createProducer(contact);
+
+        // check if already blocked
+        if(blocked.containsKey(contact)){
+            System.out.println(contact + " is already blocked.");
+            return isCurrentCorespondent;
+        }
+        // remove from contacts map
+        // and close his ass
+        if(ignored != null){
+            ignored.close();
+            blocked.put(contact, ignored);
+            System.out.println(contact + " has been blocked.");
+            return isCurrentCorespondent;
+        }else{
+            throw new JMSException("Could not block contact: " + contact);
+        }   
+        
     }
 
 
@@ -219,6 +237,7 @@ public class ChatHandler {
 
     /**
      * Returns a thread object to handle receiving messages
+     * checks if sender is blocked before displaying
      * @param consumer
      * @return Thread
      */
@@ -232,13 +251,18 @@ public class ChatHandler {
                     // receive message with timeout
                     Message msg = consumer.receive(100); // 100ms timeout
                     if (msg instanceof TextMessage tm) {
-                        // handle received message
-                        String sender = tm.getStringProperty("sender");
 
-                        // display message if sender is not blocked
+                        // message contents
-                        if (!isBlocked(sender)) {
+                        String sender = tm.getStringProperty("sender");
-                            String body = tm.getText();
+                        String body = tm.getText();
-                            displayMessage(sender, body);
+
+                        // display conditions
+                        boolean isBlocked = blocked.containsKey(sender);
+                        boolean isEmptyMessage = body.isBlank() || body.isEmpty();
+
+                        // display only if not blocked and not empty
+                        if (!isBlocked && !isEmptyMessage) {
+                            System.out.println("[" + sender + "]: " + body);
                         }
                         
                     }
@@ -258,47 +282,6 @@ public class ChatHandler {
     }
 
 
-    /**
-     * Display received message
-     * Checks if sender is blocked
-     * checks if message is empty for status update
-     * checks for exit condition
-     * @param tm
-     * @throws JMSException
-     */
-
-    private void displayMessage(String sender, String body) {
-        
-        
-        // Exit condition because correspondent went offline
-        if(body.equalsIgnoreCase("exit")) { 
-            setStatus(0);
-            return;
-        }
-
-        // display only if not empty
-        if(!body.isBlank() || !body.isEmpty()) {
-            // Status handling for online/offline
-            System.out.println("[" + sender + "]: " + body);
-        }
-        setStatus(1);
-
-    }
-
-    /**
-     * Check if sender is blocked
-     * if sender is blocked, print info message
-     * @param sender
-     * @return
-     */
-    private boolean isBlocked(String sender) {
-        boolean isBlocked = blocked.containsKey(sender);
-        if(isBlocked){
-            System.out.println(" >> Message from '"+sender+"' ignored. because user is blocked.");
-        }
-        return isBlocked;
-    }
-
     /**
      * Prompt for user ID
      * @param sc
@@ -306,7 +289,6 @@ public class ChatHandler {
     public void promptForUser(Scanner sc){
 
         System.out.print("Enter your user ID: ");
-        //userId = prompt(sc);
         setUserId(prompt(sc));
         // Instructions
         System.out.print("Welcome "+getUserId());
@@ -327,6 +309,7 @@ public class ChatHandler {
             System.out.println(contact + " is currently blocked. Unblock to chat.");
             return;
         }
+        System.out.println("You can start with: " + getCorespondent());
     }
 
     /**
@@ -367,30 +350,5 @@ public class ChatHandler {
 
     public void setCorespondent(String corespondent) {
         this.corespondent = corespondent;
-        System.out.println("You can chat with: " + corespondent);
-        // reset old status when new corepondent is set
-        setStatus(0);
-    }
-
-    /**
-     * Updates corespondents status
-     * @param status
-     */
-    private void setStatus(int status) {
-
-        // just in case of duplicate status messages, if status is same, return
-        if(this.status == status) {
-            return; 
-        }
-
-        // update status
-        this.status = status;
-
-        // and print accordingly
-        if(status == 0) {
-            System.out.println(getCorespondent()+" is now offline.");
-        } else {
-            System.out.println(getCorespondent()+" is now online.");
-        }
     }
 }