Socket Threads

package SocketTCP;

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

public class SocketClient {
    public static void main(String[] args) throws IOException {

        BufferedReader userInput = new BufferedReader(new InputStreamReader(System.in));
        Socket socketClient = new Socket("localhost", 5056);

        DataOutputStream toServer;
        toServer = new DataOutputStream(socketClient.getOutputStream());

        DataInputStream fromServer;
        fromServer = new DataInputStream(socketClient.getInputStream());

        String phrase;
        phrase = userInput.readLine();

        toServer.writeBytes(phrase + '\n');
        String phraseModifiee = fromServer.readLine();

        System.out.println("Reçu du serveur : " + phraseModifiee);
        socketClient.close();
    }
}





package SocketTCP;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) throws IOException {
        // server is listening on port 5056
        ServerSocket ss = new ServerSocket(5056);

        // running infinite loop for getting
        // client request
        while (true) {
            Socket s = null;

            try {
                // socket object to receive incoming client requests
                s = ss.accept();

                System.out.println("A new client is connected : " + s);

                // obtaining input and out streams
                BufferedReader fromClient = new BufferedReader(new InputStreamReader(s.getInputStream()));
                DataOutputStream toClient = new DataOutputStream(s.getOutputStream());

                System.out.println("Assigning new thread for this client");

                // create a new thread object
                Thread t = new ClientHandler(s, fromClient, toClient);

                // Invoking the start() method
                t.start();

            } catch (Exception e) {
                s.close();
                e.printStackTrace();
            }
        }
    }
}


package SocketTCP;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.Date;

class ClientHandler extends Thread
{

    final BufferedReader dis;
    final DataOutputStream dos;
    final Socket s;


    // Constructor
    public ClientHandler(Socket s, BufferedReader dis, DataOutputStream dos)
    {
        this.s = s;
        this.dis = dis;
        this.dos = dos;
    }

    @Override
    public void run()
    {
        try {

            String phrase = dis.readLine();
            System.out.println("Reçu du client : "+phrase);
            String phraseMaj = phrase.toUpperCase();
            dos.writeBytes(phraseMaj);
        }
        catch (IOException e){
            e.printStackTrace();
        }
        try
        {
            this.dis.close();
            this.dos.close();

        }catch(IOException e){
            e.printStackTrace();
        }
    }
}