Śledzę samouczki UDP na stroniehttp://docs.oracle.com/javase/tutorial/networking/datagrams/broadcasting.html , Skopiowałem cały kod i skompilowałem go, teraz Jeśli najpierw skompiluję klienta, a potem serwer, serwer wypisze to w konsoli

Exception in thread "main" java.net.BindException: Address already in use: Cannot bind
at java.net.PlainDatagramSocketImpl.bind0(Native Method)
at java.net.PlainDatagramSocketImpl.bind(Unknown Source)
at java.net.DatagramSocket.bind(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at java.net.DatagramSocket.<init>(Unknown Source)
at QuoteServerThread.<init>(QuoteServerThread.java:19)
at MulticastServerThread.<init>(MulticastServerThread.java:10)
at MulticastServer.main(MulticastServer.java:3)

Linia 19 QuoteServerThread to

socket = new DatagramSocket(12345);

Linia MulticastServerThread 10 to

public MulticastServerThread() throws IOException {
    super("MulticastServerThread"); // line 10
}

Linia MulticastServer 3 to

public class MulticastServer {
    public static void main(String[] args) throws java.io.IOException {
        new MulticastServerThread().start(); // line 3
    }
}

Jeśli najpierw uruchomię serwer, a następnie klienta, klient wypisuje go w konsoli

Exception in thread "main" java.net.BindException: Address already in use: Cannot bind
at java.net.PlainDatagramSocketImpl.bind0(Native Method)
at java.net.PlainDatagramSocketImpl.bind(Unknown Source)
at java.net.DatagramSocket.bind(Unknown Source)
at java.net.MulticastSocket.<init>(Unknown Source)
at java.net.MulticastSocket.<init>(Unknown Source)
at MulticastClient.main(MulticastClient.java:9)

Linia MulticastClient 9 to

MulticastSocket socket = new MulticastSocket(12345);

Patrząc na błędy, wydaje mi się, że ma to coś wspólnego ze słuchaniem portów, jak mogę to naprawić?

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