Merge origin/master

assignments/src/MV3500Cohort2024JulySeptember/homework2/Bavlsik/BavlsikClient.java

@@ -12,6 +12,7 @@ import java.util.Scanner;
  * @author tbavlsik
  */
 public class BavlsikClient {
+
     public final static String LOCALHOST = "0:0:0:0:0:0:0:1"; //Local host
 
     /**
@@ -21,19 +22,36 @@ public class BavlsikClient {
     public static void main(String[] args) throws Exception {
         Socket socket = new Socket(LOCALHOST, 2317);
 
-        new Thread(new Reader(socket)).start();
+        Thread readerThread = new Thread(new Reader(socket));
+        readerThread.start();
 
         PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
         Scanner scanner = new Scanner(System.in);
         while (scanner.hasNextLine()) {
-            out.println(scanner.nextLine());
+            String msg = scanner.nextLine();
+            //If the client wants to exit, type quit and close the socket
+            if(msg.equalsIgnoreCase("quit")){
+                socket.close();
+            }
+            //Checks to see if client or server closed socket, if so, end the program
+            if (socket.isClosed()) {
+                System.out.println("Connection closed. Exiting...");
+                break;
+            }
+            else{
+                out.println(msg);
+            }
         }
+        readerThread.join();
     }
 
     private static class Reader implements Runnable {
+
         private BufferedReader in;
+        private Socket socket;
 
         public Reader(Socket socket) throws IOException {
+            this.socket = socket;
             in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
         }
 
@@ -45,9 +63,15 @@ public class BavlsikClient {
                     System.out.println(message);
                 }
             } catch (IOException e) {
-                System.out.println("Error reading from server: " + e);
+                System.out.println("Disconnected from server.");
+            } finally {
+                try {
+                    socket.close();
+                } catch (IOException e) {
+                    System.out.println("Error closing socket: " + e);
+                }
             }
         }
     }
-    
+
 }

assignments/src/MV3500Cohort2024JulySeptember/homework2/Bavlsik/BavlsikServer.java

@@ -9,14 +9,18 @@ import java.io.PrintWriter;
 import java.net.InetAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
 /**
- *
+ * This class establishes a passcode protected chat server. Each client that connects
+ * is handled by a new thread and messages are broadcast to all connected clients.
  * @author tbavlsik
  */
 public class BavlsikServer {
+
     // the set clientWriters contains form all sockets the active PrintStream  
     private static Set<PrintWriter> clientWriters = new HashSet<>();
 
@@ -24,25 +28,40 @@ public class BavlsikServer {
      * @param args the command line arguments
      */
     public static void main(String[] args) {
+        ArrayList passcodes = new ArrayList<>(Arrays.asList(1, 29, 97));//Very secret passcode, wonder where those numbers came from...
         System.out.println(BavlsikServer.class.getName() + " has started..."); // it helps debugging to put this on console first
-        try (ServerSocket listener = new ServerSocket(2317)) {            
+        try (ServerSocket listener = new ServerSocket(2317)) {
             while (true) {
                 Handler handler = new Handler(listener.accept()); // create a new thread writing and reading to and from the new socket
                 OutputStream os = handler.socket.getOutputStream();
                 PrintStream ps = new PrintStream(os);
-                
+
                 InetAddress remoteAddress = handler.socket.getInetAddress();
                 int remotePort = handler.socket.getPort();
+
                 String message = remoteAddress.getHostName() + "=" + remoteAddress.getHostAddress() + ", " + remotePort + " has connected to the server.";
                 System.out.println(message);
-                ps.println("Welcome " + remoteAddress.getHostName() + "=" + remoteAddress.getHostAddress() + ", " + remotePort + " to the group chat!");
-                for (PrintWriter writer : clientWriters) {
+                BufferedReader reader = new BufferedReader(new InputStreamReader(handler.socket.getInputStream()));
+                ps.println("Enter a passcode:");
+                String passInput = reader.readLine(); // read the entire line as a string
+
+                int pass = Integer.parseInt(passInput.trim());
+
+                //Validate the client entered passcode
+                if (passcodes.contains(pass)) {
+                    ps.println("Welcome " + remoteAddress.getHostName() + "=" + remoteAddress.getHostAddress() + ", " + remotePort + " to the group chat!");
+                    for (PrintWriter writer : clientWriters) {
                         writer.println(message);
                     }
-                ps.flush();
-                handler.start();               
+                    ps.flush();
+                    handler.start();
+                } else {//Kick the client from the server.
+                    ps.println("Not a valid passcode.");
+                    System.out.println(remoteAddress.getHostName() + "=" + remoteAddress.getHostAddress() + ", " + remotePort + " entered an incorrect passcode; disconnecting.");
+                    handler.socket.close();
+                }
             }
-        }catch (IOException e) {
+        } catch (IOException e) {
             System.err.println("Problem with " + BavlsikServer.class.getName() + " networking: " + e);
 
             // Provide more helpful information to user if exception occurs due to running twice at one time
@@ -50,10 +69,11 @@ public class BavlsikServer {
                 System.err.println("*** Be sure to stop any other running instances of programs using this port!");
             }
         }
-            
+
     }
-    
+
     private static class Handler extends Thread {
+
         public final Socket socket;
         private PrintWriter out;
         private BufferedReader in;
@@ -71,10 +91,10 @@ public class BavlsikServer {
                 synchronized (clientWriters) {
                     clientWriters.add(out);
                 }
-
+                //Read in the message sent by the client and then send it to all other connected clients
                 String message;
                 while ((message = in.readLine()) != null) {
-                    String outputMessage = socket.getInetAddress().getHostName() + "=" + socket.getInetAddress().getHostAddress() + ", " + socket.getPort()+ ": " + message;
+                    String outputMessage = socket.getInetAddress().getHostName() + "=" + socket.getInetAddress().getHostAddress() + ", " + socket.getPort() + ": " + message;
                     System.out.println(outputMessage);
                     for (PrintWriter writer : clientWriters) {
                         writer.println(outputMessage);
@@ -83,6 +103,9 @@ public class BavlsikServer {
             } catch (IOException e) {
                 System.out.println("Error handling client: " + e);
             } finally {
+                //if a client disconnects or is kicked from the server, close the socket and broadcast the message to the chat
+                String disconnectMessage = (socket.getInetAddress().getHostName() + "=" + socket.getInetAddress().getHostAddress() + ", " + socket.getPort() + " has disconnected.");
+                System.out.println(disconnectMessage);
                 try {
                     socket.close();
                 } catch (IOException e) {
@@ -92,8 +115,11 @@ public class BavlsikServer {
                 synchronized (clientWriters) {
                     clientWriters.remove(out);
                 }
+                for (PrintWriter writer : clientWriters) {
+                    writer.println(disconnectMessage);
+                }
             }
         }
     }
-    
+
 }

assignments/src/MV3500Cohort2024JulySeptember/homework2/Bavlsik/README.md

@@ -3,8 +3,18 @@
 ***
 
 ## Description
-Modification of TcpExample3 and adding some code to implement a chat room with multiple clients.
+Modification of TcpExample3 and adding some code to implement a passcode protected 
+chat room with multiple clients.
 
-The 'BavlsikServer' class sets up a server that listens for incoming client connections on port 2317. When a client connects, the server creates a new handler thread for managing communication with that client. Each client's messages are broadcast to all other connected clients.
+The 'BavlsikServer' class sets up a server that listens for incoming client connections 
+on port 2317. When a client connects, the server creates a new handler thread for 
+managing communication with that client. After the connection is established, 
+the server prompts the client for a passcode. If the client enters a valid passcode 
+they are added to teh chat room where each client's messages are broadcast to all 
+other connected clients. If the passcode is entered incorrectly, they client is 
+disconnected from the server. If a client enters 'quit' they disconnect from the server.
 
-The 'BavlsikClient' class connects to a server running on localhost at port 2317. It sends user input from the console to the server and displays messages received from the server.
+The 'BavlsikClient' class connects to a server running on localhost at port 2317. 
\ No newline at end of file
+If the client enters a correct passcode, they are added to the chatroom, if it is 
+incorrect they are disconnecte. The client then sends user input from the console 
+to the server and displays messages received from the server.
\ No newline at end of file