ChatApplication.java

package chatapplication;

public class ChatApplication {

    public static void main (String args[]){

        ChatController  c   =   null;

        try {
            c = new ChatController(3666);

            System.out.println("connected");

            c.startReading();
            c.startWriting();

            c.close();
        } catch (java.io.IOException e){
            System.out.format("Couldn't not estabilish a connection (%s)", e.getMessage());
        }
    }

}

<<<<<<<<<< ChatController class >>>>>>>>>>>>>>>>>>

package chatapplication;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class ChatController extends Thread {

    private ServerSocket    server  = null;
    private Host            host    = null;
    private Scanner         reader  = null;

    public ChatController(int port) throws IOException{
        this.server = new ServerSocket(port);
        this.reader = new Scanner(System.in);
        this.host = new Host(server.accept());
    }

    public ChatController(String address, int port) throws IOException{
        this.host = new Host(new Socket(address, port));
        this.reader = new Scanner(System.in);
    }

    @Override
    public void run (){
        while (this.isConnected()){
            System.out.println(this.host.read());
        }
    }

    public void startReading () {
        this.start();
    }

    public void startWriting (){
        while (this.isConnected()){
            this.host.write(this.reader.nextLine());
        }
    }

    public boolean isConnected(){
        return this.host.isConnected();
    }

    public void close () throws IOException{
        this.host.close();
        if (server != null){
            server.close();
        }
    }

}

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Host class >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
package chatapplication;

import java.util.Scanner;
import java.io.PrintStream;
import java.net.Socket;

public class Host {

    private Socket              socket;
    private Scanner             reader;
    private PrintStream         writer;

    public Host (Socket socket) throws java.io.IOException{
        this.socket = socket;
        this.reader = new Scanner(socket.getInputStream());
        this.writer = new PrintStream(socket.getOutputStream());
    }

    /**
     * Writes content to the connected socket.
     * @param text, the content to send to the other socket.
     */
    public void write(String text){
        this.writer.println(text);
        this.writer.flush();
    }

    /**
     * Reads content from the connected socket.
     * @return the content read.
     */
    public String read(){
        return this.reader.nextLine();
    }

    /**
     * Close the connection.
     * @throws java.io.IOException
     */
    public void close() throws java.io.IOException {
        this.reader.close();
        this.writer.close();
        this.socket.close();
    }

    public boolean isConnected (){
        return !(this.socket.isInputShutdown() && this.socket.isOutputShutdown());
    }

}