Client - Server MultiThreading

[The_Real_Gimmy]

Ciao a tutti! Premetto che sono nuovo riguardo la programmazione java e ad oggetti. Ho la seguente situazione: ho un server che quando viene contattato dal client genera un thread e una socket e scambia dati con il client. Fin qui tutto ok, pero ora vorrei che quando il client contatta il server, quest'ultimo generi 3 o piu thread ognuno dei quali calcola dei dati e li passa, sempre sulla stessa socket in modo concorrente al client.

Server.java

import java.util.*;
import java.lang.*;
import java.io.*;
import java.net.*;
 
/**
* This is to help people to write Client server application
*  I tried to make it as simple as possible... the client connect to the server
*  the client send a String to the server the server returns it in UPPERCASE thats all
*/
public class Server {
 
        // the socket used by the server
        private ServerSocket serverSocket;
		public int i=0;
        // server constructor
        Server(int port) {
               
                /* create socket server and wait for connection requests */
                try
                {
                        serverSocket = new ServerSocket(port);
                        System.out.println("Server waiting for client on port " + serverSocket.getLocalPort());
 
                        while(true)
                        {
                                Socket socket = serverSocket.accept();  // accept connection
                                System.out.println("New client asked for a connection");
								for(i=0; i<3; i++){
									TcpThread t = new TcpThread(socket);    // make a thread of it
							//		TcpThread t2 = new TcpThread(socket);    // make a thread of it
							//		TcpThread t3 = new TcpThread(socket);    // make a thread of it
									System.out.println("Starting thread " + i);
									t.start();
							//		t2.start();
							//		t3.start();
								}
								
                        }
                }
                catch (IOException e) {
                        System.out.println("Exception on new ServerSocket: " + e);
                }
        }               
 
//        you must "run" server to have the server run as a console application
        public static void main(String[] arg) {
                // start server on port 1500
                new Server(1500);
        }
       
        /** One instance of this thread will run for each client */
        class TcpThread extends Thread {
                // the socket where to listen/talk
                Socket socket;
                DataInputStream Sinput;
                DataOutputStream Soutput;
               
                TcpThread(Socket socket) {
                        this.socket = socket;
                }
                synchronized public void run() {
                        /* Creating both Data Stream */
                        System.out.println("Thread " + i + " trying to create Object Input/Output Streams");
                        try
                        {
                                // create output first
                                Soutput = new DataOutputStream(socket.getOutputStream());
                        //        Soutput.flush();
                                Sinput  = new DataInputStream(socket.getInputStream());
                        }
                        catch (IOException e) {
                                System.out.println("Exception creating new Input/output Streams: " + e);
                                return;
                        }
                        System.out.println("Thread " + i + " waiting for a String from the Client");
                        // read a String (which is an object)
                        try {		
						
							// creazione vettore di interi
							double[] vettore = new double[10];
							for(int i=0; i<10; i++){
								vettore[i] = Math.random()*Integer.MAX_VALUE;
							}
							// individuazione del valore var1
							double var1=0;
							for(int i=0; i<10; i++){
								if(i==0)
									var1=vettore[i];
								if(var1>vettore[i])
									var1=vettore[i];
							}
						// mi faccio inviare il var2 dal professor
                            double var2 = (double) Sinput.readDouble();
                        //        var1 = var1.toUpperCase();
							System.out.println("Ricevuto var2 = " + var2);
						// se il mio var1 è > del suo var2 allora glielo invio
							if(var1>var2){
								System.out.println("var1 = " + var1 + " > var2 = " + var2 + " => INVIO\n\n");
								Soutput.writeDouble(var1);
                        //      Soutput.flush();
							}else{
								System.out.println("var1 = " + var1 + " < var2 = " + var2 + " => NON INVIO\n\n");
							}
                        }
                        catch (IOException e) {
                                System.out.println("Exception reading/writing Streams: " + e);
                                return;                               
                        }
                        // will surely not happen with a String
                    //    catch (ClassNotFoundException o) {                               
                    //    }
                        finally {
                                try {
                                        Soutput.close();
                                        Sinput.close();
                                }
                                catch (Exception e) {                                       
                                }
                        }
                }
        }
		
}

Client.java

import java.util.*;
import java.lang.*;
import java.io.*;
import java.net.*;
 
public class Client {
 
		public static double var2=0;
 
        DataInputStream Sinput;                // to read the socker
        DataOutputStream Soutput;              // to write on the socket
        Socket socket;
 
        // Constructor connection receiving a socket number
        Client(int port) {
                // we use "localhost" as host name, the server is on the same machine
                // but you can put the "real" server name or IP address
                try {
                        socket = new Socket("localhost", port);
                }
                catch(Exception e) {
                        System.out.println("Error connectiong to server:" + e);
                        return;
                }
                System.out.println("Connection accepted " + socket.getInetAddress() + ":" + socket.getPort());
 
                /* Creating both Data Stream */
                try
                {
                        Sinput  = new DataInputStream(socket.getInputStream());
                        Soutput = new DataOutputStream(socket.getOutputStream());
                }
                catch (IOException e) {
                        System.out.println("Exception creating new Input/output Streams: " + e);
                        return;
                }
                // now that I have my connection
    //            String test = "aBcDeFgHiJkLmNoPqRsTuVwXyZ";
	

	
                // send the string to the server
                System.out.println("Client sending \"" + var2 + "\" to server");
                try {
                        Soutput.writeDouble(var2);
                //        Soutput.flush();
                }
                catch(IOException e) {
                        System.out.println("Error writing to the socket: " + e);
                        return;
                }
                // read back the answer from the server
                double response;
                try {
                        response = (double) Sinput.readDouble();
                        System.out.println("Read back from server: " + response);
						var2=response;
                }
                catch(Exception e) {
                        System.out.println("Problem reading back from server: " + e);
                }
               
                try{
                        Sinput.close();
                        Soutput.close();
                }
                catch(Exception e) {}
        } 
 
        public static void main(String[] arg) throws IOException {
				
				BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
				String sceltaString;
				int scelta=0;
				do{
					System.out.println("\nCosa vuoi fare?");
					System.out.println("1) Contattare i Telescopi. ( var2 attuale = " + var2 + " )");
					System.out.println("2) Terminare l'esperimento.");
					System.out.print("Scelta: ");
					
					System.out.flush();
					sceltaString = in.readLine();
					
					scelta = Integer.parseInt(sceltaString);
					
					
					switch (scelta){
						case 1:
							new Client(1500);
						break;
						
						case 2:
							System.exit(0);
 
						default:
							System.out.println("\n!! Scegli il numero 1 o il numero 2 !! \n");
					}	
					
				}while(scelta!=2);
        }
}

Grazi a chiunque possa aiutarmi!