Outer class manipulation from Inner class

Question about the task

Chat (part 15)

Java Multithreading, Level 6, Lesson 15

Resolved

What am I doing wrong here?

protected void notifyConnectionStatusChanged(boolean clientConnected) {
    Client.this.clientConnected = clientConnected;
    synchronized (Client.this) { notify(); }
}

Let's write the implementation of the SocketThread class. We'll start with simple helper methods.

Add methods that will be available to subclasses but not accessible to other classes outside the package:
1) void processIncomingMessage(String message) - It should display the message on the console.
2) void informAboutAddingNewUser(String userName) - It should display a message indicating that a participant named userName has joined the chat.
3) void informAboutDeletingNewUser(String userName) - It should display a message indicating that the participant named userName has left the chat.
4) void notifyConnectionStatusChanged(boolean clientConnected) - This method
must: a) Set the external Client object's clientConnected field equal to the passed argument.
b) Notify (wake) the Client class's waiting main stream.

Hint: use synchronization at the level of the current instance of the outer class and use the notify() method. The SocketThread class's outer class is the Client class.

Requirements:

The processIncomingMessage() method should display the message received as an argument.
The informAboutAddingNewUser() method should display a message indicating that a user has connected to the chat.
The informAboutDeletingNewUser() method should display a message indicating that a user has left the chat.
The notifyConnectionStatusChanged() method should set the value of the clientConnected field of the outer Client object equal to the passed argument.
The notifyConnectionStatusChanged() method should call the notify() method on the outer Client object.

package com.codegym.task.task30.task3008; import java.io.IOException; import java.net.ServerSocket; import java.net.Socket; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; public class Server { private static Map<String, Connection> connectionMap = new ConcurrentHashMap<>(); public static void main (String[] args) { try (ServerSocket serverSocket = new ServerSocket(ConsoleHelper.readInt())) { ConsoleHelper.writeMessage("Server is running"); while (true) { try (Socket socket = serverSocket.accept()) { new Handler(socket).start(); } catch (Exception e) { System.out.println(e.getMessage()); } } } catch (Exception e) { e.getMessage(); } } public static void sendBroadcastMessage (Message message) { try { for (Map.Entry<String, Connection> entry : connectionMap.entrySet()) { Connection connection = entry.getValue(); connection.send(message); } } catch (IOException e) { ConsoleHelper.writeMessage("Message couldn't be sent."); } } private static class Handler extends Thread { private Socket socket; public Handler (Socket socket) { this.socket = socket; } @Override public void run() { String userName = null; ConsoleHelper.writeMessage("A connection has been established with " + socket.getRemoteSocketAddress()); try (Connection connection = new Connection(socket)) { userName = serverHandshake(connection); sendBroadcastMessage(new Message(MessageType.USER_ADDED, userName)); notifyUsers(connection, userName); serverMainLoop(connection, userName); } catch (Exception e) { ConsoleHelper.writeMessage("An error occurred while communicating with the remote address."); } finally { if (userName != null) connectionMap.remove(userName); sendBroadcastMessage(new Message(MessageType.USER_REMOVED, userName)); } ConsoleHelper.writeMessage("Connection with " + socket.getRemoteSocketAddress() + " closed."); } private String serverHandshake (Connection connection) throws IOException, ClassNotFoundException { Message nameRequest = new Message(MessageType.NAME_REQUEST); Message response; connection.send(nameRequest); while(true) { response = connection.receive(); if(response.getType() != MessageType.USER_NAME || response.getData().isEmpty() || response == null || connectionMap.containsKey(response.getData())) { connection.send(nameRequest); continue; } connectionMap.put(response.getData(),connection); connection.send(new Message (MessageType.NAME_ACCEPTED)); return response.getData(); } // Message nameRequest = new Message(MessageType.NAME_REQUEST); // Message response; // // do { // connection.send(nameRequest); // response = connection.receive(); // } while (response == null || // response.getType() != MessageType.USER_NAME || // response.getData() == null || // response.getData().isEmpty() || // connectionMap.containsKey(response.getData())); // // connectionMap.put(response.getData(), connection); // connection.send(new Message (MessageType.NAME_ACCEPTED)); // // return response.getData(); } private void notifyUsers (Connection connection, String userName) throws IOException { for (Map.Entry<String, Connection> entry : connectionMap.entrySet()) { if (!entry.getKey().equals(userName)) { connection.send(new Message(MessageType.USER_ADDED, entry.getKey())); } } } private void serverMainLoop (Connection connection, String userName) throws IOException, ClassNotFoundException { while (true) { Message received = connection.receive(); if (received.getType() == MessageType.TEXT) { sendBroadcastMessage(new Message (received.getType(), userName + ": " + received.getData())); } else { ConsoleHelper.writeMessage("Error. Message type is not \"TEXT\"."); } } } } }

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Andrew

Level 29 , Seattle, United States

28 May 2019, 16:19

solution

Managed to figure it out. Needed to call notify on the Client object, not on the SocketThread. Didn't change anything for the clientConnected statement.