discussion entre serveur/client via TCP

import java.net.*;
import java.io.*;
 
 
public class serveurTCP {
	
	static int port = 9333;
	
	public static void main(String[] args)throws Exception {
		
			ServerSocket serveur = new ServerSocket(port); //initialisation du serveur sur l'adresse local et sur le port 9333
			Socket client = serveur.accept(); //on accepte le prochain client qui essaye de se connecter
			String ligne;
			try {
				// on cré reader, le buffer qui se cre a partir de l'objet inputstreamreader et qui recupere le flux du client
				BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
				//la on recupere le flux d'ecriture vers le client
				BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
				String message = "votre ligne a bien ete lu par le serveur";
				writer.write(message);
				while((ligne = reader.readLine()) != null)
					System.out.println(ligne);
				writer.flush();
				writer.close();
				reader.close();
			
		}catch(Exception e) {
			System.out.println("fatal error");
			e.printStackTrace();
		}
	}
	
 
}
 Et voici le code de ma socket cliente:

import java.net.*;
import java.io.*;
 
public class clientTcp {
	
	public static void main(String[] args)throws Exception {
		InetAddress ip = InetAddress.getLocalHost();
		int port = 9333;
		Socket client = new  Socket(ip, port);
		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
		String donneEnvoye = "yoann";
		writer.write(donneEnvoye);
		BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
		String donneLu = null;
		while((donneLu = reader.readLine()) != null)
		System.out.println(donneLu);
		
		writer.flush();
		writer.close();
		reader.close();
	}
	
 
}

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

public class clientTcp {
	
	public static void main(String[] args)throws Exception {
		InetAddress ip = InetAddress.getLocalHost();
		int port = 9333;
		Socket client = new  Socket(ip, port);
		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
		String donneEnvoye = "yoann";
		writer.write(donneEnvoye);
		writer.flush();
		BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
		String donneLu = null;
		while((donneLu = reader.readLine()) != null)
		System.out.println(donneLu);
		
		writer.close();
		reader.close();
	}
	

}

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


public class serveurTCP {
	
	static int port = 9333;
	
	public static void main(String[] args)throws Exception {
		
			ServerSocket serveur = new ServerSocket(port); //initialisation du serveur sur l'adresse local et sur le port 9333
			Socket client = serveur.accept(); //on accepte le prochain client qui essaye de se connecter
			String ligne;
			try {
				// on cré reader, le buffer qui se cre a partir de l'objet inputstreamreader et qui recupere le flux du client
				BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
				//la on recupere le flux d'ecriture vers le client
				BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
				String message = "votre ligne a bien ete lu par le serveur";
				writer.write(message);
				writer.flush();
				while((ligne = reader.readLine()) != null)
					System.out.println(ligne);
				writer.close();
				reader.close();
			
		}catch(Exception e) {
			System.out.println("fatal error");
			e.printStackTrace();
		}
	}
	

}

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;

public class serveurTCP {
	
	static int port = 9333;
	
	public static void main(String[] args)throws Exception {
		
			ServerSocket serveur = new ServerSocket(port); //initialisation du serveur sur l'adresse local et sur le port 9333
			Socket client = serveur.accept(); //on accepte le prochain client qui essaye de se connecter
			String ligne;
			try {
				// on cré reader, le buffer qui se cre a partir de l'objet inputstreamreader et qui recupere le flux du client
				BufferedReader
				reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
				//la on recupere le flux d'ecriture vers le client
				BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
				String message = "votre ligne a bien ete lu par le serveur\n";
				writer.write(message);
				writer.flush();
				while((ligne = reader.readLine()) != null)
					System.out.println(ligne);
				writer.close();
				reader.close();
			
		}catch(Exception e) {
			System.out.println("fatal error");
			e.printStackTrace();
		}
	}
	

}



class clientTcp {
	
	public static void main(String[] args)throws Exception {
		InetAddress ip = InetAddress.getLocalHost();
		int port = 9333;
		Socket client = new  Socket(ip, port);
		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
		String donneEnvoye = "yoann\n";
		writer.write(donneEnvoye);
		writer.flush();
		BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
		String donneLu = null;
		while((donneLu = reader.readLine()) != null)
		System.out.println(donneLu);
		
		writer.close();
		reader.close();
	}
	

}

package com.daedric.net;



import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.io.ObjectOutputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.net.Socket;

import java.util.Scanner;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;



/**

 * @author Thomas

 */

public class Connection {

	private InputStream		in;



	private Lock			lock;



	private PrintWriter		out;



	private OutputStream	outstream;



	private Scanner			sc;



	public Socket			sock;



	public Connection(Socket i) throws IOException {



		sock = i;

		in = sock.getInputStream();

		outstream = sock.getOutputStream();

		out = new PrintWriter(outstream, true);

		sc = new Scanner(in);

		lock = new ReentrantLock();



	}



	public void flush() throws IOException {

		lock.lock();

		getOutputStream().flush();

		this.out.flush();

		lock.unlock();

	}



	public synchronized boolean sendFile(String file) {

		return sendFile(new File(file));

	}



	public boolean sendFile(File file) {

		lock.lock();

		try {

			FileInputStream inf = new FileInputStream(file);

			int c = 0;

			while ((c = inf.read()) > -1)

				outstream.write(c);

			outstream.flush();



		}

		catch (FileNotFoundException e) {

			e.printStackTrace();

			return false;

		}

		catch (IOException e) {

			e.printStackTrace();

			return false;

		}

		finally {

			lock.unlock();

		}

		return true;



		//

	}



	public InputStream getInputStream() {

		return in;

	}



	/**

	 * @return the outstream

	 */

	public OutputStream getOutputStream() {

		return outstream;

	}



	public PrintWriter getPrintWriterStream() {

		return out;

	}



	/**

	 * @return the sc

	 */

	public Scanner getScan() {

		return sc;

	}



	/**

	 * @return the sock

	 */

	public Socket getSock() {

		return sock;

	}



	public void sendMes(Object Mess) {

		lock.lock();

		// System.out.println("message envoye => " + Mess);

		this.out.println(Mess);

		this.out.flush();

		lock.unlock();



	}



	public void sendObj(Object Mess) {

		lock.lock();

		try {

			ObjectOutputStream out = new ObjectOutputStream(getOutputStream());

			out.writeObject(Mess);

			out.flush();

		}

		catch (IOException e) {

			e.printStackTrace();

		}

		finally {

			lock.unlock();

		}

	}



	/**

	 * @param sock

	 *            the sock to set

	 */

	public void setSock(Socket sock) {

		this.sock = sock;

	}



	public String toString() {

		return "" + sock.getInetAddress();

	}



	public boolean is(String ip) {

		String localIp = this.toString();

		return ip.compareTo(localIp = localIp.indexOf('/') > 0 ? localIp

				.substring(localIp.indexOf('/') + 1) : localIp) == 0 ? true

				: false;

	}



	/**

	 * ferme toutes les connections

	 * 

	 */

	protected void close() {

		try {

			this.flush();

			this.getInputStream().close();

			this.getOutputStream().close();

			this.getSock().close();

		}

		catch (IOException e) {

			e.printStackTrace();

		}



	}

}

package com.daedric.dmess.message;

import java.io.Serializable;

import javax.swing.ImageIcon;

import com.daedric.swing.text.TextStylizer;

public class Message implements Requestable, Serializable {

        private static final long       serialVersionUID        = -1061459363120194710L;
        private TextStylizer            doc                                     = null;
        private ImageIcon[]                     img                                     = null;
        private String                          dest                            = null;
        private String                          emetteur                        = null;
        private MessageType                     type                            = null;
        private MessengerAction         mac                                     = null;
        private Object                          arg                                     = null;

        public <T extends Serializable> Message(MessageType t, MessengerAction ac,
                        T arg, String emetteur) {

                this(t, ac, arg, null, emetteur, null, new ImageIcon[0]);
	}

        public <T extends Serializable, K extends TextStylizer> Message(
                        MessageType t, String dest, String emetteur, K doc,
			ImageIcon... img) {
                this(t, null, null, dest, emetteur, doc, img);
        }

	public <T extends Serializable, K extends TextStylizer> Message(
                        MessageType t, MessengerAction ac, T arg, String dest,
                        String emetteur, K doc, ImageIcon... img) {
                this.dest = dest;
		this.arg = arg;
                this.emetteur = emetteur;
                this.doc = doc;
                this.img = img;
		this.type = t;
                this.mac = ac;
                if (this.type == null || this.emetteur == null)
                        throw new NullPointerException("arguments null : type ="
				+ this.type + "\nemetteur =" + this.emetteur);
	}

	public TextStylizer getDoc() {
		return doc;
	}

	public ImageIcon[] getImg() {
		return img;
	}

	public String getDest() {
		return dest;
	}

	public String getEmetteur() {
		return emetteur;
	}

	public MessageType getMessageType() {
		return type;
	}

	@SuppressWarnings("unchecked")
	public <T extends Serializable> T getArg() {
		if (arg instanceof Serializable)
			return (T) arg;
		return null;
	}

	public MessengerAction getMessageAction() {
		return mac;
	}

	public String toString() {
		return "emetteur = " + this.getEmetteur() + "\ndestinataire = "
				+ this.getDest() + "\nMessageType = " + this.getMessageType()
				+ "\nMessageAction = " + this.getMessageAction() + "\narg = "
				+ this.getArg();
	}
}

Socket client = new Socket("xx.xx.xx.xxx", 9333);