Spring Integration - TCP - Response Correlation - spring-integration

Question

I'm new to Spring Integration. The situation is that I've to connect to Tcp server dynamically(i.e. the DNS will be dynamically generated at runtime based on some params). Because of this I'm using Service Activator to manually create Tcp Connections and send messages. I've overridden CachingClientConnectionFactory to make use of shared connections concept(with single-use='false'). I was listening to messages using TcpReceivingChannelAdaptor by overriding "onMessage" method. The problem is that the server either responds with a Success or failure(with Generic messages) with no CorrelationID. Is there any way to correlate the request with the response ?
I tried using TcpOutboundGateway, but with this approach also I get the same problem. I used TcpConnectionSupport to send messages :
//Sample Code.
final String correlationId = "" // Dynamic unique number
TcpOutboundGateway outboundGateway = new TcpOutboundGateway(){
public synchronized boolean onMessage(Message<?> message) {
ByteArrayToStringConverter converter = new ByteArrayToStringConverter();
String response = converter.convert((byte[]) message
.getPayload());
logger.info(correlationId);
return false;
}
};
DefaultCachingClientConnectionFactory connFactory = new DefaultCachingClientConnectionFactory();
TcpConnectionSupport con = connFactory.obtainConnection();
GenericMessage<String> msg = new GenericMessage<String>("Sample Message" + correlationId);
con.registerListener(outboundGateway);
con.send(msg);
// DefaultCachingClientConnectionFactory is the subclass of CachingClientConnectionFactory.
When I send multiple messages, every time I get the same correlation printed in the "onMessage" method.
I read here that Outbound Gateway will correlate messages. Please help me. Maybe I'm doing something wrong.
Thanks

Answer 1

Unless you include correlation data in the message you can't correlate a response to a request.
The gateway achieves this by only allowing one outstanding request on a socket at a time; hence the reply has to be for the request. This is not very useful at high volume with a shared connection; hence the caching client cf was introduced. The gateway keeps a map of outstanding requests based on the connection id.
The gateway, in conjunction with the caching client connection factory should do what you need. However, overriding onMessage is not a good idea, because that's where the reply correlation is done.