scambio messaggi client-server

[deleted_2024.08.22]

Salve,

allora

SERVER

class server2 {
    
    
    public static void main(String args[]) throws IOException {
        String data = "Welcome to My Server"; //welcome message
        String data1 = "enter username"; //welcome message
        String message,servermessage;

        int idstats1 = 0; //verifyed username
        int idstats2 = 0; //verifyed password 
        int verify1 = 0;
        try {
            //Detecting the localhost's ip address
            InetAddress localaddr = InetAddress.getLocalHost();
            System.out.println ("Local IP Address : " + localaddr );
            System.out.println ("Local hostname : " + localaddr.getHostAddress());

            //Creating a server socket for connection
            ServerSocket srvr = new ServerSocket(1234);
            System.out.println("Waiting for connection on "+localaddr);
            
            
while(true){
            //Accept incoming connection
            Socket skt = srvr.accept();
            System.out.print("Server has connected!\n");

            //get Input and Output streams
            PrintWriter out = new PrintWriter(skt.getOutputStream(), true);
            out.flush();
            BufferedReader in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
            System.out.print("Sending string: '" + data1 + "'\n");
            out.println(data1); //sends welcome message

            
           
            
             
              
              
}
        } catch(BindException e) {
            e.printStackTrace();
            System.out.print("A server is already running on the same port.");        
        } catch(SocketException e) {
            e.printStackTrace();
            System.out.print("Client has disconnected rudely.");
        } catch(Exception e) {
            e.printStackTrace();
            System.out.print(e);    
        }
    }}

CLIENT

class LongClient {
    public static void main(String args[]) {
        
        
        String data="ciao";
        String data1="ciao2";
        try {
            
            
            Socket skt = new Socket("localhost", 1234);
            BufferedReader in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
            
                        BufferedWriter in2 = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
                        

            Scanner kbReader = new Scanner(System.in);
            PrintWriter out = new PrintWriter(skt.getOutputStream(), true);
            out.flush();

            String message, servermessage;
            InetAddress clientip = InetAddress.getLocalHost();
            System.out.println("Preparing to chat...");
            out.println("Client IP Address: " + clientip); // sends message to client giving ip
            out.println("Client hostname: " + clientip.getHostAddress()); // send message to client giving computer name

            
            
            
                if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("server>: " + servermessage);
                    
                 
                }
 if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("server>: " + servermessage);
                    
                 
                }
 
 
 
  ServerSocket srvr = new ServerSocket(1234);
            
            
            //Accept incoming connection
            Socket skt2 = srvr.accept();
            System.out.print("Server has connected!\n");

            //get Input and Output streams
            
            out.flush();
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
                message = kbReader.nextLine();
                out.println(message);

                out.println("Done");

                //message="bye";
                //out.println("bye");
                Thread.currentThread().sleep(300);
            
            
            
                //get Input and Output streams
           
            
            
            
            
            
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
            System.out.print("Sending string: '" + data1 + "'\n");
            out.println(data1); //sends welcome message

            in2.write(data, 200, 200);
            
//reads the line typed in
            
            

            out.close();
            in.close();
        } catch(Exception e) {
            System.out.print(e);
        }
    } 
}

Ora il mio problema e che come fa il client ad inviare messaggi al server.

Il server invia correttamente i due messaggi il client ma non riesco a inviare i messagi dal client al server. Come posso risolvere?

[deleted_2024.08.22]

Salve,

allora

SERVER

class server2 {
    
    
    public static void main(String args[]) throws IOException {
        String data = "Welcome to My Server"; //welcome message
        String data1 = "enter username"; //welcome message
        String message,servermessage;

        int idstats1 = 0; //verifyed username
        int idstats2 = 0; //verifyed password 
        int verify1 = 0;
        try {
            //Detecting the localhost's ip address
            InetAddress localaddr = InetAddress.getLocalHost();
            System.out.println ("Local IP Address : " + localaddr );
            System.out.println ("Local hostname : " + localaddr.getHostAddress());

            //Creating a server socket for connection
            ServerSocket srvr = new ServerSocket(1234);
            System.out.println("Waiting for connection on "+localaddr);
            
            
while(true){
            //Accept incoming connection
            Socket skt = srvr.accept();
            System.out.print("Server has connected!\n");

            //get Input and Output streams
            PrintWriter out = new PrintWriter(skt.getOutputStream(), true);
            out.flush();
            BufferedReader in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
            System.out.print("Sending string: '" + data1 + "'\n");
            out.println(data1); //sends welcome message

            
           
            
             
              
              
}
        } catch(BindException e) {
            e.printStackTrace();
            System.out.print("A server is already running on the same port.");        
        } catch(SocketException e) {
            e.printStackTrace();
            System.out.print("Client has disconnected rudely.");
        } catch(Exception e) {
            e.printStackTrace();
            System.out.print(e);    
        }
    }}

CLIENT

class LongClient {
    public static void main(String args[]) {
        
        
        String data="ciao";
        String data1="ciao2";
        try {
            
            
            Socket skt = new Socket("localhost", 1234);
            BufferedReader in = new BufferedReader(new InputStreamReader(skt.getInputStream()));
            
                        BufferedWriter in2 = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
                        

            Scanner kbReader = new Scanner(System.in);
            PrintWriter out = new PrintWriter(skt.getOutputStream(), true);
            out.flush();

            String message, servermessage;
            InetAddress clientip = InetAddress.getLocalHost();
            System.out.println("Preparing to chat...");
            out.println("Client IP Address: " + clientip); // sends message to client giving ip
            out.println("Client hostname: " + clientip.getHostAddress()); // send message to client giving computer name

            
            
            
                if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("server>: " + servermessage);
                    
                 
                }
 if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("server>: " + servermessage);
                    
                 
                }
 
 
 
  ServerSocket srvr = new ServerSocket(1234);
            
            
            //Accept incoming connection
            Socket skt2 = srvr.accept();
            System.out.print("Server has connected!\n");

            //get Input and Output streams
            
            out.flush();
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
                message = kbReader.nextLine();
                out.println(message);

                out.println("Done");

                //message="bye";
                //out.println("bye");
                Thread.currentThread().sleep(300);
            
            
            
                //get Input and Output streams
           
            
            
            
            
            
            
            
            System.out.print("Sending string: '" + data + "'\n");
            out.println(data); //sends welcome message
            System.out.print("Sending string: '" + data1 + "'\n");
            out.println(data1); //sends welcome message

            in2.write(data, 200, 200);
            
//reads the line typed in
            
            

            out.close();
            in.close();
        } catch(Exception e) {
            System.out.print(e);
        }
    } 
}

Ora il mio problema e che come fa il client ad inviare messaggi al server.

Il server invia correttamente i due messaggi il client ma non riesco a inviare i messagi dal client al server. Come posso risolvere?

Per far si che il client invia messaggi il server ho utilizzato il

                   
 BufferedWriter in2 = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
            Socket skt = new Socket("localhost", 1234);


            in2.write("ciao", 200, 200);

ed nel server ho utilizzato il BufferedReader ed evidentemente non funziona

[deleted_2024.08.22]

Per far si che il client invia messaggi il server ho utilizzato il

                   
 BufferedWriter in2 = new BufferedWriter(new OutputStreamWriter(skt.getOutputStream()));
            Socket skt = new Socket("localhost", 1234);


            in2.write("ciao", 200, 200);

ed nel server ho utilizzato il BufferedReader ed evidentemente non funziona

La cosa strana e se nel server mado una stringa con

out.println(data);

il client la riceve con

   
              if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("server>: " + servermessage);
                    
                 
                }

mentre poi dopo aver ricevuto questo messaggio faccio la prova a inviare con out.println("prova") il server con

 if (in.ready()) {
                    servermessage = in.readLine();
                    System.out.println("client>: " + servermessage);
                    
                 
                }

il server non riceve nessun messaggio, come mai?