error in main

Code:

---

        else if (args[0].equals("-s")) {
            if (args.length < 2) {
                System.out.println("You must specify a port number. E.g, java cw1 -s 231");
            }
            else {
                System.out.println("Please enter a secret key which both the client and server will share:");
                BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
                String line = r.readLine().trim();

               
                SECRET_KEY = line;
               
                try {
                    int port = Integer.parseInt(args[1]);
                    serverStart(port);
                }
                catch (NumberFormatException e) {
                    System.out.println("Invalid port number");
                }       
            } 
        }

---

this is the serverStart method

Code:

---

    public static void serverStart(int port) throws IOException {
        ServerSocket s = new ServerSocket(port);
        System.out.println("Server is now awaiting for incoming connections on port " + port);

        while (true) {
            try {
                Socket client = s.accept();

                DataOutputStream out = new DataOutputStream(new BufferedOutputStream(client.getOutputStream()));
                DataInputStream in = new DataInputStream(new BufferedInputStream(client.getInputStream()));
            }
            catch (Exception e ) {}
        }
    }

---

so basically in the command line i do
java cw1 -s 123

but before it should start listening on port 123, it should ask me for the key which it does. i enter 'hello' and it gives me error

Code:

---

C:\Documents and Settings\admin\Desktop\Cryptography>java cw1 -s 123
java cw1 -s 123
Please enter a secret key which both the client and server will share:
hello
Exception in thread "main" 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.<init>(Unknown Source)
        at java.net.ServerSocket.<init>(Unknown Source)
        at cw1.serverStart(cw1.java:62)
        at cw1.main(cw1.java:36)

---

Never heard of Windows listening on NTP automatically, but who knows ...

Try a much higher port, e.g. 10010. The ports below 1024 are reserved for "well-known services" anyway and often taken.