I have implement the chat sever.When I start to type the message to the server It says"Server has close the connection: java.io.EOFException"
I don't what went wrong with my code.
Can you plz have a look at it or give me some advice.

public class threadMiddle extends Thread {
    
 
    public static int Port;    
    int numberOfClient ;
    JTextArea textArea;
    TextField numOfClient;
    String setNum;
    String ClientName;
    
    	// a unique ID for each connection
	private static int uniqueId;
	// an ArrayList to keep the list of the Client
	private ArrayList<ClientThread> al;
	// if I am in a GUI
	private serverUI sg;
	// to display time
	private SimpleDateFormat sdf;
	// the port number to listen for connection
	private int port;
	// the boolean that will be turned of to stop the server
	private boolean keepGoing;
	
    

    
    
    // This class gets portNumber, textArea and TextField from serverUI class.

        
        threadMiddle(int port,JTextArea a,TextField NOC){
        
        this.Port = port;
        textArea = a;
        numOfClient = NOC;
        sdf = new SimpleDateFormat("HH:mm:ss");
	// ArrayList for the Client list
	al = new ArrayList<ClientThread>();
     
        
    }
    

    
    
    public void run()
    {
        keepGoing=true;
        try
        {
            //develop socket with each client
            ServerSocket serverSocket = new ServerSocket(Port);
            
         
            while(keepGoing)
            {
                
                
                numberOfClient = Integer.valueOf(numOfClient.getText());
                
                
                
                
                  Socket clientSocket = serverSocket.accept();
                    if(!keepGoing)
                    break;
                    ClientThread t = new ClientThread(clientSocket);  // make a thread of it
                    al.add(t);									// save it in the ArrayList
                    t.start();
               
                numberOfClient++;
                
                
                
                
                // number of client in text field
                setNum = String.valueOf(numberOfClient);
                numOfClient.setText(setNum);                
                textArea.setText(textArea.getText()+"\nTotal connected client are "+numberOfClient);
            
                // start clientHandler to create a response for each of clients
             
              //  new clientHandler(clientSocket,textArea,numOfClient).start();
                
                        
            }
            
            
            
        }
        catch(Exception e)
        {
            
           e.printStackTrace();
        }
    }
        private void display(String msg) {
		String time = sdf.format(new Date()) + " " + msg;
		if(sg == null)
			System.out.println(time);
		else
			textArea.setText(time + "\n");
	}
	/*
	 *  to broadcast a message to all Clients
	 */
	private synchronized void broadcast(String message) {
		// add HH:mm:ss and \n to the message
		String time = sdf.format(new Date());
		String messageLf = time + " " + message + "\n";
		// display message on console or GUI
		if(sg == null)
			System.out.print(messageLf);
		else
			textArea.setText(messageLf);     // append in the room window
		
		// we loop in reverse order in case we would have to remove a Client
		// because it has disconnected
		for(int i = al.size(); --i >= 0;) {
			ClientThread ct = al.get(i);
			// try to write to the Client if it fails remove it from the list
			if(!ct.writeMsg(messageLf)) {
				al.remove(i);
				display("Disconnected Client " + ct.username + " removed from list.");
			}
		}
	}

	// for a client who logoff using the LOGOUT message
	synchronized void remove(int id) {
		// scan the array list until we found the Id
		for(int i = 0; i < al.size(); ++i) {
			ClientThread ct = al.get(i);
			// found it
			if(ct.id == id) {
				al.remove(i);
				return;
			}
		}
	}
    
    class ClientThread extends Thread {
		// the socket where to listen/talk
		Socket socket;
		ObjectInputStream sInput;
		ObjectOutputStream sOutput;
		// my unique id (easier for deconnection)
		int id;
		// the Username of the Client
		String username;
		// the only type of message a will receive
		ChatMessage cm;
		// the date I connect
		String date;

		// Constructore
		ClientThread(Socket socket) {
			// a unique id
			id = ++uniqueId;
			this.socket = socket;
			/* Creating both Data Stream */
			System.out.println("Thread trying to create Object Input/Output Streams");
			try
			{
				// create output first
				sOutput = new ObjectOutputStream(socket.getOutputStream());
				sInput  = new ObjectInputStream(socket.getInputStream());
				// read the username
				username = (String) sInput.readObject();
				display(username + " just connected.");
			}
			catch (IOException e) {
				display("Exception creating new Input/output Streams: " + e);
				return;
			}
			// have to catch ClassNotFoundException
			// but I read a String, I am sure it will work
			catch (ClassNotFoundException e) {
			}
            date = new Date().toString() + "\n";
		}

		// what will run forever
		public void run() {
			// to loop until LOGOUT
			boolean keepGoing = true;
			while(keepGoing) {
				// read a String (which is an object)
				try {
					cm = (ChatMessage) sInput.readObject();
				}
				catch (IOException e) {
					display(username + " Exception reading Streams: " + e);
					break;				
				}
				catch(ClassNotFoundException e2) {
					break;
				}
				// the messaage part of the ChatMessage
				String message = cm.getMessage();

				// Switch on the type of message receive
				switch(cm.getType()) {

				case ChatMessage.MESSAGE:
					broadcast(username + ": " + message);
					break;
				case ChatMessage.LOGOUT:
					display(username + " disconnected with a LOGOUT message.");
					keepGoing = false;
					break;
				case ChatMessage.WHOISIN:
					writeMsg("List of the users connected at " + sdf.format(new Date()) + "\n");
					// scan al the users connected
					for(int i = 0; i < al.size(); ++i) {
						ClientThread ct = al.get(i);
						writeMsg((i+1) + ") " + ct.username + " since " + ct.date);
					}
					break;
				}
			}
			// remove myself from the arrayList containing the list of the
			// connected Clients
			remove(id);
			close();
		}
		
		// try to close everything
		private void close() {
			// try to close the connection
			try {
				if(sOutput != null) sOutput.close();
			}
			catch(Exception e) {}
			try {
				if(sInput != null) sInput.close();
			}
			catch(Exception e) {};
			try {
				if(socket != null) socket.close();
			}
			catch (Exception e) {}
		}

		/*
		 * Write a String to the Client output stream
		 */
		private boolean writeMsg(String msg) {
			// if Client is still connected send the message to it
			if(!socket.isConnected()) {
				close();
				return false;
			}
			// write the message to the stream
			try {
				sOutput.writeObject(msg);
			}
			// if an error occurs, do not abort just inform the user
			catch(IOException e) {
				display("Error sending message to " + username);
				display(e.toString());
			}
			return true;
		}
	}
}

I have implement the chat sever.When I start to type the message to the server It says"Server has close the connection: java.io.EOFException"
I don't what went wrong with my code.
Can you plz have a look at it or give me some advice.

public class threadMiddle extends Thread {
    
 
    public static int Port;    
    int numberOfClient ;
    JTextArea textArea;
    TextField numOfClient;
    String setNum;
    String ClientName;
    
    	// a unique ID for each connection
	private static int uniqueId;
	// an ArrayList to keep the list of the Client
	private ArrayList<ClientThread> al;
	// if I am in a GUI
	private serverUI sg;
	// to display time
	private SimpleDateFormat sdf;
	// the port number to listen for connection
	private int port;
	// the boolean that will be turned of to stop the server
	private boolean keepGoing;
	
    

    
    
    // This class gets portNumber, textArea and TextField from serverUI class.

        
        threadMiddle(int port,JTextArea a,TextField NOC){
        
        this.Port = port;
        textArea = a;
        numOfClient = NOC;
        sdf = new SimpleDateFormat("HH:mm:ss");
	// ArrayList for the Client list
	al = new ArrayList<ClientThread>();
     
        
    }
    

    
    
    public void run()
    {
        keepGoing=true;
        try
        {
            //develop socket with each client
            ServerSocket serverSocket = new ServerSocket(Port);
            
         
            while(keepGoing)
            {
                
                
                numberOfClient = Integer.valueOf(numOfClient.getText());
                
                
                
                
                  Socket clientSocket = serverSocket.accept();
                    if(!keepGoing)
                    break;
                    ClientThread t = new ClientThread(clientSocket);  // make a thread of it
                    al.add(t);									// save it in the ArrayList
                    t.start();
               
                numberOfClient++;
                
                
                
                
                // number of client in text field
                setNum = String.valueOf(numberOfClient);
                numOfClient.setText(setNum);                
                textArea.setText(textArea.getText()+"\nTotal connected client are "+numberOfClient);
            
                // start clientHandler to create a response for each of clients
             
              //  new clientHandler(clientSocket,textArea,numOfClient).start();
                
                        
            }
            
            
            
        }
        catch(Exception e)
        {
            
           e.printStackTrace();
        }
    }
        private void display(String msg) {
		String time = sdf.format(new Date()) + " " + msg;
		if(sg == null)
			System.out.println(time);
		else
			textArea.setText(time + "\n");
	}
	/*
	 *  to broadcast a message to all Clients
	 */
	private synchronized void broadcast(String message) {
		// add HH:mm:ss and \n to the message
		String time = sdf.format(new Date());
		String messageLf = time + " " + message + "\n";
		// display message on console or GUI
		if(sg == null)
			System.out.print(messageLf);
		else
			textArea.setText(messageLf);     // append in the room window
		
		// we loop in reverse order in case we would have to remove a Client
		// because it has disconnected
		for(int i = al.size(); --i >= 0;) {
			ClientThread ct = al.get(i);
			// try to write to the Client if it fails remove it from the list
			if(!ct.writeMsg(messageLf)) {
				al.remove(i);
				display("Disconnected Client " + ct.username + " removed from list.");
			}
		}
	}

	// for a client who logoff using the LOGOUT message
	synchronized void remove(int id) {
		// scan the array list until we found the Id
		for(int i = 0; i < al.size(); ++i) {
			ClientThread ct = al.get(i);
			// found it
			if(ct.id == id) {
				al.remove(i);
				return;
			}
		}
	}
    
    class ClientThread extends Thread {
		// the socket where to listen/talk
		Socket socket;
		ObjectInputStream sInput;
		ObjectOutputStream sOutput;
		// my unique id (easier for deconnection)
		int id;
		// the Username of the Client
		String username;
		// the only type of message a will receive
		ChatMessage cm;
		// the date I connect
		String date;

		// Constructore
		ClientThread(Socket socket) {
			// a unique id
			id = ++uniqueId;
			this.socket = socket;
			/* Creating both Data Stream */
			System.out.println("Thread trying to create Object Input/Output Streams");
			try
			{
				// create output first
				sOutput = new ObjectOutputStream(socket.getOutputStream());
				sInput  = new ObjectInputStream(socket.getInputStream());
				// read the username
				username = (String) sInput.readObject();
				display(username + " just connected.");
			}
			catch (IOException e) {
				display("Exception creating new Input/output Streams: " + e);
				return;
			}
			// have to catch ClassNotFoundException
			// but I read a String, I am sure it will work
			catch (ClassNotFoundException e) {
			}
            date = new Date().toString() + "\n";
		}

		// what will run forever
		public void run() {
			// to loop until LOGOUT
			boolean keepGoing = true;
			while(keepGoing) {
				// read a String (which is an object)
				try {
					cm = (ChatMessage) sInput.readObject();
				}
				catch (IOException e) {
					display(username + " Exception reading Streams: " + e);
					break;				
				}
				catch(ClassNotFoundException e2) {
					break;
				}
				// the messaage part of the ChatMessage
				String message = cm.getMessage();

				// Switch on the type of message receive
				switch(cm.getType()) {

				case ChatMessage.MESSAGE:
					broadcast(username + ": " + message);
					break;
				case ChatMessage.LOGOUT:
					display(username + " disconnected with a LOGOUT message.");
					keepGoing = false;
					break;
				case ChatMessage.WHOISIN:
					writeMsg("List of the users connected at " + sdf.format(new Date()) + "\n");
					// scan al the users connected
					for(int i = 0; i < al.size(); ++i) {
						ClientThread ct = al.get(i);
						writeMsg((i+1) + ") " + ct.username + " since " + ct.date);
					}
					break;
				}
			}
			// remove myself from the arrayList containing the list of the
			// connected Clients
			remove(id);
			close();
		}
		
		// try to close everything
		private void close() {
			// try to close the connection
			try {
				if(sOutput != null) sOutput.close();
			}
			catch(Exception e) {}
			try {
				if(sInput != null) sInput.close();
			}
			catch(Exception e) {};
			try {
				if(socket != null) socket.close();
			}
			catch (Exception e) {}
		}

		/*
		 * Write a String to the Client output stream
		 */
		private boolean writeMsg(String msg) {
			// if Client is still connected send the message to it
			if(!socket.isConnected()) {
				close();
				return false;
			}
			// write the message to the stream
			try {
				sOutput.writeObject(msg);
			}
			// if an error occurs, do not abort just inform the user
			catch(IOException e) {
				display("Error sending message to " + username);
				display(e.toString());
			}
			return true;
		}
	}
}

can you post the full error message including the line number

It's OIException I can connect to the server but later on when i type some it will automatically close the connection

It's OIException I can connect to the server but later on when i type some it will automatically close the connection

That is definitely not the full error message,Please paste the full error message with the line number and the stacktrace, do this by putting ex.printStackTrace() in your try catch exceptions, and first you said there was an EOFException now an OIException, is there even an OIException???

Edited 4 Years Ago by DavidKroukamp: n/a

java.io.EOFException
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2553)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1296)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:350)
at Client$ListenFromServer.run(Client.java:226)

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