Dynamic TCP Server with Spring Integration using Java DSL

Question

I am trying to create a TCP server and client by reading the property files which contains the detail of the connections. I am using Dynamic and runtime Integration Flows with the help of following reference document ( 9.20 Dynamic and runtime Integration Flows)

The code is working fine while creating the client but when I am creating the server using the same with changes in the code as follow:

    IntegrationFlow flow = f -> f
            .handle(Tcp.inboundAdapter(Tcp.netServer(2221)
                    .serializer(TcpCodecs.crlf())
                    .deserializer(TcpCodecs.lengthHeader1())
                    .id("server")))
            .transform(Transformers.objectToString());

    IntegrationFlowRegistration theFlow = this.flowContext.registration(flow).register();

I am getting the following error:

Caused by: java.lang.IllegalArgumentException: Found ambiguous parameter type [class java.lang.String] for method match: [public java.lang.Class<?> org.springframework.integration.dsl.IntegrationComponentSpec.getObjectType(), public S org.springframework.integration.dsl.MessageProducerSpec.outputChannel(java.lang.String), public S org.springframework.integration.dsl.MessageProducerSpec.outputChannel(org.springframework.messaging.MessageChannel), public org.springframework.integration.ip.dsl.TcpInboundChannelAdapterSpec org.springframework.integration.ip.dsl.TcpInboundChannelAdapterSpec.taskScheduler(org.springframework.scheduling.TaskScheduler), public S org.springframework.integration.dsl.MessageProducerSpec.errorMessageStrategy(org.springframework.integration.support.ErrorMessageStrategy), public S org.springframework.integration.dsl.MessageProducerSpec.phase(int), public S org.springframework.integration.dsl.MessageProducerSpec.autoStartup(boolean), public S org.springframework.integration.dsl.MessageProducerSpec.sendTimeout(long)]
    at org.springframework.util.Assert.isNull(Assert.java:155)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.findHandlerMethodsForTarget(MessagingMethodInvokerHelper.java:843)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:362)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:231)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.<init>(MessagingMethodInvokerHelper.java:225)
    at org.springframework.integration.handler.MethodInvokingMessageProcessor.<init>(MethodInvokingMessageProcessor.java:60)
    at org.springframework.integration.handler.ServiceActivatingHandler.<init>(ServiceActivatingHandler.java:38)
    at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:924)
    at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:904)
    at org.springframework.integration.dsl.IntegrationFlowDefinition.handle(IntegrationFlowDefinition.java:891)
    at org.springframework.integration.samples.dynamictcp.DynamicTcpClientApplication.lambda$1(DynamicTcpClientApplication.java:194)
    at org.springframework.integration.config.dsl.IntegrationFlowBeanPostProcessor.processIntegrationFlowImpl(IntegrationFlowBeanPostProcessor.java:268)
    at org.springframework.integration.config.dsl.IntegrationFlowBeanPostProcessor.postProcessBeforeInitialization(IntegrationFlowBeanPostProcessor.java:96)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:423)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1702)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:583)
    ... 16 common frames omitted

Please help me with above issue. Also I have found the code for dynamic tcp client but no code is present for dynamic tcp server(any resource or link where I can take an idea to create dynamic server).

Answer 1

You are mixing responsibility. The Tcp.inboundAdapter() must be a first in the IntegrationFlow chain. Consider to use this instead:

IntegrationFlow flow =  
   IntegrationFlows.from(Tcp.inboundAdapter(Tcp.netServer(2221)
                .serializer(TcpCodecs.crlf())
                .deserializer(TcpCodecs.lengthHeader1())
                .id("server")))
        .transform(Transformers.objectToString())
        .get();