Why is it broken ?!! I tried with diffenrent approaches it stiil fails to pass

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I tried with a bunch of ways but none of them passes . I don't have a clue where did the infinite loop come from even if I change the loops into finite loops (using counter)

Let's start writing the main functionality of the Client class.

1) Add a public void run() method. It should create a helper SocketThread, wait until it establishes a connection with the server, and then in a loop, read messages from the console and send them to the server. The loop will terminate either when the client shuts down or the user enters the 'exit' command'.
To inform the main thread that the connection is established on the helper thread, use the Client object's wait() and notify() methods.

The implementation should:
a) Create a new socket thread using the getSocketThread() method.
b) Mark the created thread as a daemon. This is necessary so that the helper thread is automatically interrupted when the program exits.
c) Start the helper thread.
d) Make the current thread wait until it receives a notification from another thread.
Hint: use wait() and object level synchronization. If an exception occurs while waiting, notify the user and exit the program.
d) Once the thread receives a notification, check the value of clientConnected. If it is true, display "Connection established. To exit, enter 'exit'.". If it is false, display "An error occurred while working with the client.".
e) Read messages from the console until the client is connected. If 'exit' is entered, then exit the loop.
g) After each string is read, if the shouldSendTextFromConsole() method returns true, send the text using the sendTextMessage() method.

2) Add the public static void main(String[] args) method. It must create a new Client object and call its run() method.

Requirements:

The main() method should create a new Client object and call its run() method.
The run() method should create and start a new thread that is obtained using the getSocketThread() method.
The thread created using the getSocketThread() method should be marked as a daemon (setDaemon(true)).
After starting the new socketThread, the run() method should wait until it is awakened.
As long as the clientConnected flag is true, messages should be read from the console using the ConsoleHelper.readString() method.
If the "exit" command is entered, you should interrupt the message-reading loop.
If the shouldSentTextFromConsole() method returns true, the sendTextMessage() method should be called with the input text used as an argument.

package com.codegym.task.task30.task3008; import java.net.*; import java.util.Map; import java.io.*; import java.util.concurrent.ConcurrentHashMap; public class Server { private static Map<String, Connection> connectionMap = new ConcurrentHashMap<String, Connection>(); public static void sendBroadcastMessage(Message message) { for(Map.Entry<String, Connection> pair : connectionMap.entrySet()) { try { ((Connection) pair.getValue()).send(message); } catch(IOException e ) { ConsoleHelper.writeMessage("The message couldn't be sent "); } } } public static void main(String[] args){ ServerSocket serverSocket = null ; try{ int port = ConsoleHelper.readInt(); serverSocket = new ServerSocket(port); ConsoleHelper.writeMessage("The server is running "); while(true){ Socket socket = serverSocket.accept(); Handler handler = new Handler(socket); handler.start(); } } catch(Exception e){ try{ if( serverSocket != null) serverSocket.close(); } catch(IOException ex){ } ConsoleHelper.writeMessage(e.getMessage()); } } private static class Handler extends Thread { private final Socket socket ; private Connection connection ; private String userName ; public Handler(Socket socket) throws IOException { this.socket = socket; } @Override public void run() { String userName = null; Connection connection = null; do { try { ConsoleHelper.writeMessage("New connection was established with a remote address " + socket.getRemoteSocketAddress()); connection = new Connection(socket); } catch (Exception ig) { break; } try { userName = serverHandshake(connection); } catch (Exception ig) { try { connection.close(); } catch (IOException e) { e.printStackTrace(); } break; } try { sendBroadcastMessage(new Message(MessageType.USER_ADDED, userName)); notifyUsers(connection, userName); serverMainLoop(connection, userName); } catch (Exception e) { } finally { connectionMap.remove(userName); sendBroadcastMessage(new Message(MessageType.USER_REMOVED, userName)); try { connection.close(); } catch (IOException e1) { e1.printStackTrace(); } } } while (false); ConsoleHelper.writeMessage("Connection closed: " + socket.getRemoteSocketAddress()); } private String serverHandshake(Connection connection) throws IOException,ClassNotFoundException{ for(int i =0 ; i < 1000; i++) { connection.send(new Message(MessageType.NAME_REQUEST,"Enter your username" )); Message response = connection.receive(); if(!isValidResponse(response)) continue; if(!isValidUsername(response.getData())) continue ; connectionMap.put(response.getData(), connection); connection.send(new Message(MessageType.NAME_ACCEPTED, "Request accepted")); return response.getData(); } return null ; } private void notifyUsers(Connection connection, String userName) throws IOException{ for(Map.Entry<String , Connection > pair : connectionMap.entrySet()){ if(pair.getKey().equals(userName)) continue; connection.send(new Message(MessageType.USER_ADDED, pair.getKey())); } } private void serverMainLoop(Connection connection, String userName) throws IOException, ClassNotFoundException{ Message messageReceived = null ; while(true) { if((messageReceived = connection.receive()).getType() == MessageType.TEXT) { Message messageToBeSent = new Message(MessageType.TEXT, userName + ": "+ messageReceived.getData()); sendBroadcastMessage(messageToBeSent); } else ConsoleHelper.writeMessage("message couldn't get sent"); } } private boolean isValidResponse(Message response) { return !(response == null || response.getType() != MessageType.USER_NAME ); } private boolean isValidUsername(String username) { return !(username.isEmpty() || connectionMap.containsKey(username)); } private void closeConnection(Connection connection) { if(connection != null) { try { connection.close(); } catch(IOException ex) { } } } } }

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Anonymous #10436715

Level 38

1 May 2020, 11:32

solution

Hi. Replace this:

synchronized(connection) {
	  try {
	if(!clientConnected) wait();
	    notify();

with this:

synchronized (this) {
    wait();
}

SOUFIANE DAHIMI

Level 32 , Marrakech, Morocco

1 May 2020, 17:15

Thanks a lot