tcp-outbound-gateway - failed to send Message to channel

[thehin]

Hello,

I am trying to follow the tcp sample off GitHub (http://git.springsource.org/spring-i...ver/readme.txt) and I am getting an error when trying to send a message to a tcp server. The error I get is "failed to send Message to channel." Below is my xml configuration. What am I doing wrong :-(. I am using Spring Integration 2.0.1 RELEASE.

<beans:beans xmlns:beans="http://www.springframework.org/schema/beans"
			 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
			 xmlns="http://www.springframework.org/schema/integration"
			 xmlns:context="http://www.springframework.org/schema/context"
			 xmlns:jms="http://www.springframework.org/schema/integration/jms"
			 xmlns:ip="http://www.springframework.org/schema/integration/ip"			 
			 xmlns:tx="http://www.springframework.org/schema/tx"
			 xsi:schemaLocation="http://www.springframework.org/schema/beans
								 http://www.springframework.org/schem...-beans-3.0.xsd
								 http://www.springframework.org/schema/context
								 http://www.springframework.org/schem...ontext-3.0.xsd
								 http://www.springframework.org/schema/integration
								 http://www.springframework.org/schem...ntegration.xsd
								 http://www.springframework.org/schema/integration/jms
								 http://www.springframework.org/schem...ration-jms.xsd
								 http://www.springframework.org/schema/integration/ip
								 http://www.springframework.org/schem...gration-ip.xsd
								 http://www.springframework.org/schema/tx
								 http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">		

	<beans:bean id="appContext" class="com.company.transport.util.AppContext" />
	
	<ip:tcp-connection-factory id="clientTcpConnectionFactory" type="client" host="localhost" port="59260" using-nio="true" so-timeout="10000" />
	<gateway id="gw" service-interface="com.company.transport.client.monitor.TransportClientMonitorGateway" default-request-channel="outgoingTcpMonitorChannel"/>
	<channel id="outgoingTcpMonitorChannel" />
	
	<ip:tcp-outbound-channel-adapter channel="outgoingTcpMonitorChannel" connection-factory="clientTcpConnectionFactory" />
	
	<ip:tcp-connection-factory id="crLfServer"
		type="server"
		port="59260"/>
			
	<ip:tcp-inbound-channel-adapter
		connection-factory="crLfServer"
		channel="serverBytes2StringChannel"/>
	
	<channel id="toSA" />
	
	<transformer id="serverBytes2String"
		input-channel="serverBytes2StringChannel"
		output-channel="toSA" 
		expression="new String(payload)"/>	
	
	<beans:bean id="transportClientMonitor" class="com.company.transport.client.monitor.TransportClientMonitor" init-method="run" />
	
</beans:beans>

[oleg.zhurakousky]

I see that you are connecting gateway to an adapter.
Gateways are by-directional while adapters are uni-directional so there will be no reply for he gateway. That is just from the first look.

Also, could you please explain your use case?

[Gary Russell]

The channel 'toSA' has no subscriber. You need to consume messages sent to it by the inbound-channel-adapter.

[thehin]

OK. So I scoured around the web for some more examples. I happened to stumble upon a post on this forum. I tried copying it and created the Gateway and Service in code but I get a new error: failure occurred in gateway sendAndReceive, failed to send Message to channel 'input'. Below is my new configuration.

<beans:beans xmlns:beans="http://www.springframework.org/schema/beans"
			 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
			 xmlns="http://www.springframework.org/schema/integration"
			 xmlns:context="http://www.springframework.org/schema/context"
			 xmlns:jms="http://www.springframework.org/schema/integration/jms"
			 xmlns:ip="http://www.springframework.org/schema/integration/ip"			 
			 xmlns:tx="http://www.springframework.org/schema/tx"
			 xsi:schemaLocation="http://www.springframework.org/schema/beans
								 http://www.springframework.org/schem...-beans-3.0.xsd
								 http://www.springframework.org/schema/context
								 http://www.springframework.org/schem...ontext-3.0.xsd
								 http://www.springframework.org/schema/integration
								 http://www.springframework.org/schem...ntegration.xsd
								 http://www.springframework.org/schema/integration/jms
								 http://www.springframework.org/schem...ration-jms.xsd
								 http://www.springframework.org/schema/integration/ip
								 http://www.springframework.org/schem...gration-ip.xsd
								 http://www.springframework.org/schema/tx
								 http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">		

	<beans:bean id="appContext" class="com.company.transport.util.AppContext" />
	
	<gateway id="gw" 
	             service-interface="com.company.transport.client.monitor.TransportClientMonitorGateway"
	             default-request-channel="input"
	             default-reply-channel="replies"/>

	<ip:tcp-connection-factory id="client"
		type="client"
		host="localhost"
		port="4700"
		single-use="true"
		so-timeout="10000"
                using-nio="true"
        />
	
	<channel id="input" />	
	<channel id="replies" />
	
	<ip:tcp-outbound-gateway id="outGateway"
		request-channel="input"
		reply-channel="replies"
		connection-factory="client"
		request-timeout="10000"
		reply-timeout="10000"
		/>
		
	<!-- Server side -->
	
	<ip:tcp-connection-factory id="crLfServer"
		type="server"
		port="4700"/>
			
	<ip:tcp-inbound-gateway id="gatewayCrLf"
		connection-factory="crLfServer"
		request-channel="toSA" />
		
	<channel id="toSA" />

	<service-activator id="SA" 
		input-channel="toSA"
		ref="echoService"
		method="test"
	/>

	<beans:bean id="echoService" class="com.company.transport.client.monitor.EchoService" />
	
	
	<beans:bean id="transportClientMonitor" class="com.company.transport.client.monitor.TransportClientMonitor" init-method="run" />
	
</beans:beans>


public interface TransportClientMonitorGateway {
	public byte[] send(String text);
}

public class EchoService {
	public String test(byte[] bytes) {
		return "echo:" + new String(bytes);
	}

}

[Gary Russell]

If you are just trying to test the client side, you can just consume messages on the server side with a <stream:stdout-channel-adapter/>. As Oleg implies, though, this configuration implies your gateway method returns void.

[Gary Russell]

My previous post was a follow up to my first post.

This new configuration uses tcp gateways instead of channel adapters.

As Oleg said, please describe your use case and we can help you with the config.

[Gary Russell]

BTW, when posting code or config, please surround it with

[ code ]

[ /code ]

(No spaces inside the brackets).

[thehin]

My use case is to have interprocess communication between a Java application running as a service via the Java Service Wrapper and a standalone Java application. I thought using TCP communication between processes would be ideal. I would like a simple command and response, telnet, like communication. I was planning on using JSON text data back and forth between the two processes. If you can suggest a better alternative then I am willing to give that a shot.

Thanks again.

[Gary Russell]

OK; it was just confusing that you were using channel adapters in the first example, when the sample you cited (from git) uses gateways. So, I assumed you changed them for a reason. Also, not having a consumer for the toSA channel would fail.

Your second attempt looks like it should work, but you don't really need the replies channel on the client side, you can let everything default to the reply channel in the outbound message's headers.

Can you provide a stack trace of the failure so I can see more details?

[thehin]

This is the stack trace I get with the 2nd configuration I had posted above: I noticed the message, "dispatcher has no subscribers.

2011-01-11 14:14:19,687  WARN [main] org.springframework.integration.gateway.GatewayProxyFactoryBean$MethodInvocationGateway - failure occurred in gateway sendAndReceive
org.springframework.integration.MessageDeliveryException: failed to send Message to channel 'input'
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:165)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:128)
	at org.springframework.integration.core.MessagingTemplate.doSend(MessagingTemplate.java:288)
	at org.springframework.integration.core.MessagingTemplate.doSendAndReceive(MessagingTemplate.java:318)
	at org.springframework.integration.core.MessagingTemplate.sendAndReceive(MessagingTemplate.java:239)
	at org.springframework.integration.core.MessagingTemplate.convertSendAndReceive(MessagingTemplate.java:274)
	at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:225)
	at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceive(MessagingGatewaySupport.java:204)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.invokeGatewayMethod(GatewayProxyFactoryBean.java:300)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.doInvoke(GatewayProxyFactoryBean.java:269)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.invoke(GatewayProxyFactoryBean.java:260)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
	at $Proxy0.send(Unknown Source)
	at com.company.transport.client.monitor.TransportClientMonitor.run(TransportClientMonitor.java:34)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeCustomInitMethod(AbstractAutowireCapableBeanFactory.java:1544)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1485)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at com.company.transport.client.monitor.TransportClientMonitor.main(TransportClientMonitor.java:114)
Caused by: java.lang.IllegalStateException: Dispatcher has no subscribers.
	at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:104)
	at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:97)
	at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:44)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:157)
	... 33 more