Question

I have the follwing code which is a thread pool in java which accepts only one client

public class ServerThread implements Runnable {

    ServerSocket serverSocket;
    Socket clientSocket;
    protected boolean isStopped = false;
    int serverPort = 6500;
    private String serverIpAddress = "127.0.0.1";
    DataInputStream is;
    ObjectOutputStream os=null;

    protected BlockingQueue queue = null;


    protected ExecutorService threadPool2 =
    Executors.newFixedThreadPool(1);

    public ServerThread(BlockingQueue queue) { 
        this.queue=queue;
    }

    public void run() {
        try {
            InetSocketAddress serverAddr = new InetSocketAddress(serverIpAddress, serverPort);
            serverSocket = new ServerSocket();
            serverSocket.bind(serverAddr);

            System.out.println("s-a creat");

        } catch (UnknownHostException e) {
            System.err.println("Don't know about host");
        } catch (IOException e) {
            e.printStackTrace();
        }


        while(!isStopped()){
            clientSocket=null;

            try{            
                clientSocket = serverSocket.accept();
    }
            catch(Exception e)
            {
                e.printStackTrace();        
            }

            WorkerServerRunnable workerRunnable = new WorkerServerRunnable(queue,clientSocket);
            this.threadPool2.execute(workerRunnable);

        }
        this.threadPool2.shutdown();
        System.out.println("Server Stopped.");
    }

    private synchronized boolean isStopped(){
        return this.isStopped;
    }

    public synchronized void stop() {
        this.isStopped = true;
        try {
            this.serverSocket.close();
        } catch (IOException e) {
            throw new RuntimeException("Error closing server", e);
        }

    }

}

But the problem is that I cannot get my server in ON state.
I mean once I press run I get the following error:

java.net.SocketException: Socket is not bound yet
at java.net.ServerSocket.accept(Unknown Source)
at servers.ServerThread.run(ServerThread.java:60)
at java.lang.Thread.run(Unknown Source)
java.net.BindException: Address already in use: JVM_Bind
at java.net.PlainSocketImpl.socketBind(Native Method)
at java.net.PlainSocketImpl.bind(Unknown Source)
at java.net.ServerSocket.bind(Unknown Source)
at java.net.ServerSocket.bind(Unknown Source)
at servers.ServerThread.run(ServerThread.java:44)
at java.lang.Thread.run(Unknown Source)

Even if I shutdown my whole app and run it again still the same error….has anyone any idea why?Thank u!

Answer 1

Some other program is already using port 6500. Check that you’re not running another instance of your program.

Try running

netstat -lp

to see what processes are using which ports. Make sure the port on which you wish to listen is not listed in the output from netstat.