Question About Streams

Question

I have two threads, each with
socket.getOutputStream()).writeObject(message);
in a server, and a client reading messages from both threads (everything uses the same socket). Sometimes, a message is not recieved; is this because one message overwrites eachother, or do streams naturally lose data from time to time? Would syncronizing the threads help me at all? I really don't know how to tackle this problem.

Answer 1

Here's the shell of a little app I built a while ago that seems to work pretty well. Left parts of the implementation to you:
import java.io.*;
import java.net.*;
import java.util.Vector;
public class Server {
     private static class Connection implements Runnable {
          private Socket socket;
          private ObjectInputStream ois;
          private ObjectOutputStream oos;
          public Connection( Socket socket ) {
               this.socket = socket;
               try {
                    ois = new ObjectInputStream(socket.getInputStream());
                    oos = new ObjectOutputStream(socket.getOutputStream());
               } catch (Exception ex) {
                    ex.printStackTrace();
          public void run() {
               Object message;
               try {
                    while( (message = ois.readObject()) != null ) {
                    System.out.println("Read an object.");
                         // this is where you'd handle the deserialization
               } catch (Exception ex) {
                    ex.printStackTrace();
          public void sendMessage( Object message ) {
               try {
                    oos.writeObject(message);
               } catch (Exception ex) {
                    ex.printStackTrace();
     private static ServerSocket server;
     private static Vector<Connection> connections;
     public static void main( String[] argv ) throws Throwable {
          server = new ServerSocket(8080);
          connections = new Vector<Connection>();
          while( true ) {
               Connection connection = new Connection(server.accept());
               synchronized(connections) { connections.add(connection); }
               new Thread(connection).start();
}