Server + Thread

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */


import java.net.*;
import java.io.*;

public class ChatServerThread extends Thread
{

    private ChatServer server = null;
    private Socket socket = null;
    private int ID = -1;
    private BufferedReader streamIn = null;
    private PrintWriter streamOut = null;

    public ChatServerThread(ChatServer _server, Socket _socket)
    {
        super();
        server = _server;
        socket = _socket;
        ID = socket.getPort();
    }

    public void send(String msg)
    {
        streamOut.println(msg);
    }

    public int getID()
    {
        return ID;
    }

    @Override
    public void run()
    {
        System.out.println("Server Thread " + ID + " running.");
        while (true && !this.isInterrupted())
        {
            try
            {
                server.handle(ID, streamIn.readLine());
            } catch (IOException ioe)
            {
                System.out.println(ID + " ERROR reading: " + ioe.getMessage());
                server.remove(ID);
                this.interrupt();
            }
        }
    }

    public void open() throws IOException
    {
        streamIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        streamOut = new PrintWriter(socket.getOutputStream(), true);
    }


    public void close() throws IOException
    {
        if (socket != null)
        {
            socket.close();
        }
        if (streamIn != null)
        {
            streamIn.close();
        }
        if (streamOut != null)
        {
            streamOut.close();
        }
    }
}

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */


import java.net.*;
import java.io.*;

public class ChatServer implements Runnable
{

    private ChatServerThread clients[] = new ChatServerThread[50];
    private ServerSocket server = null;
    private Thread thread = null;
    private int clientCount = 0;

    public ChatServer(int port)
    {
        try
        {
            System.out.println("Binding to port " + port + ", please wait  ...");
            server = new ServerSocket(port);
            System.out.println("Server started: " + server);
            start();
        } catch (IOException ioe)
        {
            System.out.println("Can not bind to port " + port + ": " + ioe.getMessage());
        }
    }

    @Override
    public void run()
    {
        while (thread != null && !thread.isInterrupted())
        {
            try
            {
                System.out.println("Waiting for a client ...");
                addThread(server.accept());
            } catch (IOException ioe)
            {
                System.out.println("Server accept error: " + ioe);
                stop();
            }
        }
    }

    private int findClient(int ID)
    {
        for (int i = 0; i < clientCount; i++)
        {
            if (clients[i].getID() == ID)
            {
                return i;
            }
        }
        return -1;
    }

    public synchronized void handle(int ID, String input)
    {
        if (input.equals(".bye"))
        {
            clients[findClient(ID)].send(".bye");
            remove(ID);
        } else
        {
            for (int i = 0; i < clientCount; i++)
            {
                clients[i].send(ID + ": " + input);
            }
        }
    }

    public synchronized void remove(int ID)
    {
        int pos = findClient(ID);
        if (pos >= 0)
        {
            ChatServerThread toTerminate = clients[pos];
            System.out.println("Removing client thread " + ID + " at " + pos);
            if (pos < clientCount - 1)
            {
                for (int i = pos + 1; i < clientCount; i++)
                {
                    clients[i - 1] = clients[i];
                }
            }
            clientCount--;
            try
            {
                toTerminate.close();
            } catch (IOException ioe)
            {
                System.out.println("Error closing thread: " + ioe);
            }
            toTerminate.interrupt();
        }
    }

    private void addThread(Socket socket)
    {
        if (clientCount < clients.length)
        {
            System.out.println("Client accepted: " + socket);
            clients[clientCount] = new ChatServerThread(this, socket);
            try
            {
                clients[clientCount].open();
                clients[clientCount].start();
                clientCount++;
            } catch (IOException ioe)
            {
                System.out.println("Error opening thread: " + ioe);
            }
        } else
        {
            System.out.println("Client refused: maximum " + clients.length + " reached.");
        }
    }

    public void start()
    {
        if (thread == null)
        {
            thread = new Thread(this);
            thread.start();
        }
    }

    public void stop()
    {
        if (thread != null)
        {
            thread.interrupt();
            thread = null;
        }
    }

    public static void main(String args[])
    {
        ChatServer server = null;

        server = new ChatServer(9988);

    }
}