Sockets and oblect passing between servers

Question

Hi ..
This is my first try to make program that uses sockets
i have read the java's tutorial but what i cant understand is how can send objects instead of strings between the server and client ?
thank you in advance

Answer 1

i have created the server and client classes with success
i have used the out = new ObjectOutputStream(kkSocket.getOutputStream());
in = new ObjectInputStreamkkSocket.getInputStream());
for input and output for the client (same goes for the server class) and the code runs as expected!!!
as i have seen in some exaples they use the bufferedOutputStream and the BufferedInputStream
when i tied to use it the program dind't worked ..why?
( i have used the out = new ObjectOutputStream(new BufferedOutputStream(kkSocket.getOutputStream()));
in = new ObjectInputStream(new BufferedInputStream(kkSocket.getInputStream()));
here is the complete code
public class myServer {
      public static void main(String[] args) throws IOException {
             ServerSocket serverSocket = null;
             try {
                 serverSocket = new ServerSocket(4444);
                 System.out.println(serverSocket.toString());
                         } catch (IOException e) {
                 System.err.println("Could not listen on port: 4444.");
                 System.exit(1);
             Socket clientSocket = null;
              try {
                 clientSocket = serverSocket.accept();
             } catch (IOException e) {
                 System.err.println("Accept failed.");
                 System.exit(1);
             ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(clientSocket.getOutputStream()));
             ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(clientSocket.getInputStream()));
             MyObject inputLine, outputLine;
             outputLine = new MyObject(1);
             out.writeObject(outputLine);
             try {
                  while ((inputLine = (MyObject)in.readObject()) != null) {
                       System.out.println("server writes" + inputLine.getInt());
                       outputLine = new MyObject(inputLine.getInt());
                       out.writeObject(outputLine);
                       out.flush();
             catch (ClassNotFoundException ex){}
             out.close();
             in.close();
             clientSocket.close();
             serverSocket.close();
public class myClient {
     public static void main(String[] args) throws IOException {
        Socket kkSocket = null;
        ObjectOutputStream out = null;
        ObjectInputStream in = null;
        try {
             kkSocket = new Socket(InetAddress.getAllByName("192.168.178.21")[0],4444);
            out = new ObjectOutputStream(new BufferedOutputStream(kkSocket.getOutputStream()));
            in = new ObjectInputStream(new BufferedInputStream(kkSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: taranis.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: taranis.");
            System.exit(1);
        MyObject fromServer = new MyObject(-10);
        MyObject responseToServer;
        try {
             while ((fromServer = (MyObject)in.readObject()) != null) {
                  //pause for a while
                  for (int i =0 ; i <1000;i++);
                  System.out.println("Client Writes: " + fromServer.getInt());
                 if (fromServer.getInt()==12)break;
                 responseToServer = new MyObject(fromServer.getInt()+1);
                 System.out.println("Client Rensponses: " + responseToServer.getInt());
                 out.writeObject(responseToServer);
                 out.flush();
         catch(ClassNotFoundException e){}
        out.close();
        in.close();
        kkSocket.close();
public class MyObject implements Serializable{
     private static final long serialVersionUID = 1L;
     String str;
     int myInt;
     MyObject(int a){
          str = "A String";
          myInt = a;
     public int getInt(){
          return myInt;
}