Question

I’ve recently gotten into trying to make server-client connections. I was able to make a 1 on 1 connection with no problems, but now i’m trying to make a server that accepts multiple clients and i’m running into a problem where i can’t make the server listen to connections while there is one established… I’m not sure if i made myself clear but here’s my code:

-The main loop that waits for connections:

public class ChatMultiServer {

public static void main(String []args){

    int socknum = 124;
    ServerSocket serverSocket;
    Socket clientSocket;

    while(true){

    ////opens socket
    try{
        System.out.println("Opening port...");
        new ServerSocket(124).close();
        serverSocket = new ServerSocket(socknum);
    }catch(Exception e){System.out.println("Error 101 = failed to bind to port "+socknum+"."); break;}
    //////accepts connection
    try{
        System.out.println("Waiting for connections...");
        clientSocket = serverSocket.accept();
    }catch(Exception e){System.out.println("Error 102 = failed to accept port "+socknum+"."); break;}
    /////
    try{
        System.out.println("Initializing thread...");
        new Thread(new CMSThread(clientSocket));
    }catch(Exception e){System.out.println("Error 103 = failed to create thread."); break;}
    try{
        serverSocket.close();
    }catch(Exception e){System.out.println("Error 105 = failed to close socket.");}
    }
}

}

-The thread that handles the connections:

public class CMSThread extends Thread{
Socket socket;
BufferedReader in;
PrintWriter out;
String username;
char EOF = (char)0x00;
public CMSThread(Socket s){
    socket = s;
    run();
}
public void run(){
    try{
    System.out.println("Setting up streams...");
    in = (new BufferedReader(new InputStreamReader(socket.getInputStream())));
    out = new PrintWriter(socket.getOutputStream());
    }catch(Exception e){System.out.println("Error 204 = failed to get streams");}
    try{
        out.print("Welcome! you can quit at any tyme by writing EXIT.\nLet me introduce myself, I'm 'testprogram 1', but that doesn't really matter since you'll do the talking.\nWhat's your name?"+EOF);
        out.flush();
        username = in.readLine();
        out.print("<b>"+username+"</b>, that's a nice name.\nWell, i'll shut up now. Have fun talking to yourself while whoever is running the server observes your conversation.\n"+EOF);
        out.flush();    
    }catch(Exception e){System.out.println("Are you effin kidding me!? -.-   whatever... Error 666 = failed to chat.");}
}

}

My problem, once again, is that when the server gets a connection with a client(I’m using actionscript for the clients just because it’s easier to make a GUI), it just waits until the thread is done running to start the loop again. I’m trying to make it loop at the same time as the thread handles the chat.

I was thinking maybe i needed to make a thread for the loop as well as the thread for handling the connection, but i’m not sure as to how i would go about doing that… Please let me know if my hypothesis was somewhat right, and if it was, some guidance towards the answer would be nice.

PS: I’m sorry if my code is a bit messy or if this is a stupid question, i haven’t made a java program in a while…

Answer 1

You aren’t actually starting your new Threads – you are just directly calling run(). As far as I can see, this means that you will be executing run() in the main thread that creates each CMSThread object.

To start a Thread, you have to call thread.start().

Also, I’m not sure why you are wrapping your CMSThread in another Thread – CMSThread extends Thread so it can be started in its own right. The wrapper Thread isn’t being started either.

So you need:

        new CMSThread(clientSocket).start();

and remove the run() call from the constructor of CMSThread