How to create a simple rendezvous client-server socket cannel?

I'm trying to create a simple RendezvousChannel for client-server communication. My applications start both fine, but the message is never send. Why?

client:

@Component
public class Sender {
    @Autowired
    @Qualifier("clientChannel")
    private MessageChannel chan;

    @PostConstruct
    public void send() {
        MessagingTemplate template = new MessagingTemplate();
        Message<?> message = new Message<String>() {
            @Override
            public String getPayload() {
                return "TEST";
            }

            @Override
            public MessageHeaders getHeaders() {
                return new MessageHeaders(null);
            }
        };

        System.out.println("sending...");
        Message<?> result = template.sendAndReceive(chan, message);
        System.out.println("send: " + result.getPayload());
    }
}


@MessageEndpoint
public class ClientEndpoint {
    @Bean
    public MessageChannel clientChannel() {
        return new RendezvousChannel();
    }

    @Bean
    public TcpConnectionFactoryFactoryBean clientFactory() {
        TcpConnectionFactoryFactoryBean fact = new TcpConnectionFactoryFactoryBean();
        fact.setType("client");
        fact.setHost("localhost");
        fact.setPort(5555);
        fact.setUsingNio(true);
        fact.setSingleUse(true);
        return fact;
    }

    @Bean
    public TcpOutboundGateway out(TcpNioClientConnectionFactory factory, @Qualifier("clientChannel") MessageChannel clientChannel) throws Exception {
        TcpOutboundGateway gate = new TcpOutboundGateway();
        gate.setConnectionFactory(factory);
        gate.setReplyChannel(clientChannel);
        return gate;
    }
}

server:

@Component
public class Receiver {
    @ServiceActivator(inputChannel = "serverChannel", poller = @Poller(fixedDelay = "1000", maxMessagesPerPoll = "1"))
    public String hello(String input) throws Exception {
        System.out.println("Hello: " + input);
        return "Hello: " + input;
    }
}

@MessageEndpoint
public class ServerEndpoint {
    @Bean
    public TcpInboundGateway serverGateway(TcpConnectionFactoryFactoryBean factory, @Qualifier("serverChannel") MessageChannel serverChannel) throws Exception {
        TcpInboundGateway gate = new TcpInboundGateway();
        gate.setConnectionFactory(factory.getObject());
        gate.setRequestChannel(serverChannel);
        return gate;
    }

    @Bean
    public TcpConnectionFactoryFactoryBean clientFactory() {
        TcpConnectionFactoryFactoryBean fact = new TcpConnectionFactoryFactoryBean();
        fact.setType("server");
        fact.setHost("localhost");
        fact.setPort(5555);
        fact.setUsingNio(true);
        fact.setSingleUse(true);
        return fact;
    }

    @Bean
    public MessageChannel serverChannel() {
        return new RendezvousChannel();
    }
}

First I start the server, then the client. The client keeps ganging at "sending...", and the server never receives a message. Why?