Sockets & inetd

Question

Hello!
It all worked just fine before I used inetd to start the server. When I use inetd I get this exception:
Network error: Address already in useSo, the inetd-stuff works, because the server is started, but...
This is my code:
Client:
public class Client {
    private int port = 7654;
    private String host = "ausone";
    ObjectOutputStream out = null;
    ObjectInputStream in = null;
    public Client (String host, int port) {
        this.host = host;
        this.port = port;
        setup ();
    private void setup () {
        try {
            Socket s = new Socket(host, port);
            System.out.println ( "Connected to: " +s.getInetAddress().getHostName() );
            out = new ObjectOutputStream (s.getOutputStream());
            in = new ObjectInputStream (s.getInputStream());
            } catch (IOException e) {
                System.out.println ("Could not connect to socket: "+e);
Server:
public class Server {
    private ServerSocket server;
    public static final int DEFAULT_PORT = 7654;
    public static void main(String[] args) {
        Server tcserver = new Server();
        tcserver.runServer();
    private void runServer() {
        ServerThread newServerThread = null;
        Socket newSocket = null;
        try {
            server = new ServerSocket (DEFAULT_PORT);           //<------ Here!!
            while (true) {
                System.out.println ("Waiting for client connection");
                for(int i = 0; i < 10; i++) {
                    newSocket = server.accept ();
                    newServerThread = new ServerThread (newSocket,i);
                    newServerThread.start ();
        } catch (EOFException eofException) {
            System.out.println ("Client terminated the connection.");
        } catch (IOException ioException) {
            System.out.println ("Network error: " + ioException.getMessage());
    private class ServerThread extends Thread {
        Socket connection = null;
        private ObjectOutputStream out;
        private ObjectInputStream in;
        public ServerThread(Socket socket, int num) {
            connection = socket;
            out = new ObjectOutputStream (connection.getOutputStream());
            in = new ObjectInputStream (connection.getInputStream());
            //send client answer
            try {
                String result = "testing";
                out.writeObject (result);
            } catch (IOException e) {
                System.out.println ("IO Error "+e);
}So, what is wrong!!!
And, another thing I noticed was that I can't use ObjectInputStream anymore, then I get a InvalideStreamHeader... or something like that.
Please! I really need some help...

Answer 1

Thanks for your answers, I'm sorry for my late reply.
I have one more question for you Sylvia.
Perhaps it's just me not knowing the best way to solv
my problem, it's like this: Under my applet, I have
native codes and libraries, I don't know if that makes
it any different. The problem is that if two or more
users connect to the server at the same time the
server-code "crashes". So I need separate processes (I
think), and I thought that using inetd was the way to
do it. Otherwise, how will the server know to which
user it will send the answer? Please correct me if I'm
wrong!
LinaLina, sounds like your native code is not thread safe. If fixing that is not an option, then you're probably right that you'll need separate processes. If you want to run things from inetd, then just skip all the socket handling stuff, and treat System.out as the OutputStream you would have got from the socket, and System.in as the InputStream you would have got.
It's usual in such circumstances to provide a command line option that tells the program whether to listen on a socket first, or just go straight into processing the connection it gets from inetd. That makes development a lot easier.
That said, starting a VM is very expensive, and each one takes a lot of memory. One possible alternative is to seperate out the native code into a seperate c/c++ program that can be invoked from the Java VM, and communicated with using sockets. How practical that is depends on the extent of the natiive API, and the frequency of calls to it.
Sylvia.