Selectors and ServerSocketChannel

Hi I've problem with Selectors/Channels
I've found somewhere in web:
server:

Code:

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byte[] data = new byte[255];
                for (int i = 0; i < data.length; i++) data[i] = (byte) i;
               
                    ServerSocketChannel server = ServerSocketChannel.open();
                    server.configureBlocking(false);
                    server.socket().bind(new InetSocketAddress(9000));
                    Selector selector = Selector.open();
                    server.register(selector, SelectionKey.OP_ACCEPT);
                    while (true) {
                      selector.select();
                      Set readyKeys = selector.selectedKeys();
                      Iterator iterator = readyKeys.iterator();
                      while (iterator.hasNext()) {
                        SelectionKey key = (SelectionKey) iterator.next();
                        iterator.remove();
                        if (key.isAcceptable()) {
                          SocketChannel client = server.accept();
                          System.out.println("Accepted connection from " + client);
                          client.configureBlocking(false);
                          ByteBuffer source = ByteBuffer.wrap(data);
                          SelectionKey key2 = client.register(selector, SelectionKey.OP_WRITE);
                          key2.attach(source);
                        } else if (key.isWritable()) {
                          SocketChannel client = (SocketChannel) key.channel();
                          ByteBuffer output = (ByteBuffer) key.attachment();
                          if (!output.hasRemaining()) {
                            output.rewind();
                          }
                          client.write(output);
                        }
                        key.channel().close();
                      }
                    }

---

and client:

Code:

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public static void main(String[] args) throws Exception {
                    int port = 1919;
                    SocketAddress address = new InetSocketAddress("127.0.0.1", 9000);
                    SocketChannel client = SocketChannel.open(address);
                    ByteBuffer buffer = ByteBuffer.allocate(4);
                    IntBuffer view = buffer.asIntBuffer();
                   
                    for (int expected = 0;; expected++) {
                      client.read(buffer);
                      int actual = view.get();
                      buffer.clear();
                      view.rewind();
                      if (actual != expected) {
                        System.err.println("Expected " + expected + "; was " + actual);
                        break;
                      }
                      System.out.println(actual);
                    }
                  }

---

When I connect to server first time, everything is ok, server is working but when i try connect to server second time client gives me error:

Code:

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Exception in thread "main" java.net.ConnectException: Connection refused: connect
        at sun.nio.ch.Net.connect(Native Method)
        at sun.nio.ch.SocketChannelImpl.connect(Unknown Source)
        at java.nio.channels.SocketChannel.open(Unknown Source)
        at LClient.main(LClient.java:100)

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my firewall is off, I'm trying to use Selectors, but second conenction to server gives me that error,
please,
help
Peter