I did one simple DSL which retrieves the data from database and doing simple conversion in the service activator.
#Bean
public IntegrationFlow mainFlow() {
return IntegrationFlows.from("userChannel")
.channel("queryChannel")
.handle("sampleConvertor","convertUser")
.get();
queryChannel is a jdbc outbound gateway and sampleConverter is the service Activator.
<int-jdbc:outbound-gateway query="select * from employee where employee_id=:payload"
request-channel="queryChannel" data-source="dataSource"/>
The issue is after retrieving the data from database, the flow is not going to serviceActivator and it simply returns back the database response.
In xml configuration, I used to invoke gateway inside the chain like below.
<int:gateway id="query.gateway" request-channel="queryChannel"/>
Please suggest what I am doing wrong here. Thanks in advance.
That's a bit unusual to combine Java DSL and XML configuration, but they still work together.
Your problem I think that you are missing the fact that your queryChannel has two subscriber at runtime, not a chain of call.
The first one is <int-jdbc:outbound-gateway> and the second is that .handle("sampleConvertor","convertUser"). Right, when you declare a channel in the IntegrationFlow, the next EIP-method produces a subscriber for this channel. At the same time when you use a channel like request-channel or input-channel in the XML configuration that brings a subscriber as well.
So, you have two subscriber on the DirectChannel with the RoundRobinLoadBalancingStrategy and therefore only one of them will handle a message and if it is a request-replly component, like that <int-jdbc:outbound-gateway> it will produce a message into the output-channel or to the replyChannel in the headers. In your case the story is exactly about a replyChannel and therefore you don't go to the .handle("sampleConvertor","convertUser") because it's not the next in the chain, but just a parallel universe by the round-robin algorithm.
If you really would like to reach that .handle("sampleConvertor","convertUser") after calling the <int-jdbc:outbound-gateway>, you should consider to use .gateway("queryChannel") instead of that .channel().
Related
I am trying to test a Spring Integration flow that starts off from a message-driven-channel-adapter configured as:
<int-jms:message-driven-channel-adapter id="myAdapter" ... />
My test goes like:
#SpringJUnitConfig(locations = {"my-app-context.xml"})
#SpringIntegrationTest(noAutoStartup = {"myAdapter"})
public class MyIntegrationFlowTest {
#Autowired
private MockIntegrationContext mockIntegrationContext;
#Test
public void myTest() {
...
MessageSource<String> messageSource = () -> new GenericMessage<>("foo");
mockIntegrationContext.substituteMessageSourceFor("myAdapter", messageSource);
...
}
}
I am however getting the following error:
org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'myAdapter' is expected to be of type 'org.springframework.integration.endpoint.SourcePollingChannelAdapter' but was actually of type 'org.springframework.integration.jms.JmsMessageDrivenEndpoint'
How should one specify an alternate source for the channel adapter for testing using the MockIntegrationContext, or by some other method?
The Message Driver Channel Adapter is really not a Source Polling Channel Adapter. So, the substituteMessageSourceFor() is indeed cannot be used for that type of components, which, essentially is a MessageProducerSupport implementation, not a SourcePollingChannelAdapter for a MessageSource.
The difference exists because not all protocols provides a listener-like hooks to spawn some self-managed task to subscribe to. The good example is JDBC, which is only passive system expecting requests. Therefore a polling channel adapter with a JdbcPollingChannelAdapter (which is a MessageSource) implementation must be used to interact with DB in event-driven manner.
Other systems (like JMS in your case) provides some listener (or consumer) API for what we can spawn a while task (see MessageListenerContainer in spring-jms) and let its MessageProducerSupport to emit messages to the channel.
Therefore you need to distinguish for yourself with what type of component you interact before choosing a testing strategy.
Since there is no extra layer in case of message-driver channel adapter, but rather some specific, self-managed MessageProducerSupport impl, we not only provide a particular mocking API, but even don't require to know anything else, but just standard unit testing feature and a message channel this endpoint is producing in the configuration.
So, the solution for you is something like:
#SpringIntegrationTest(noAutoStartup = {"myAdapter"}) - that's fully correct in your code: we really have to stop the real channel adapter to not pollute our testing environment.
You just need to inject into your test class a MessageChannel that id="myAdapter" is producing to. In your test code you just build a Message and send it into this channel. No need to worry about a MockIntegrationContext at all.
A very simple example with Spring Integration 5.3.2: a single integration flow, registered using the spring-integration DSL with the IntegrationFlowContext:
`
MessageChannel startChannel = MessageChannels.direct("channel").get();
StandardIntegrationFlow flow = IntegrationFlows.from(startChannel)
.log().get();
flowContext.registration(flow)
.autoStartup(false)
.register();
flow.start();
startChannel.send(MessageBuilder.withPayload("test").build());`
Yields org.springframework.messaging.MessageDeliveryException: Dispatcher has no subscribers for channel.
Why? Adding a single .transform(e->e) (for example) resolves the problem, but obviously is a strange workaround.
That’s definitely an expected behavior. You declare a MessageChannel and send a message into it, but there are no subscribers declared for that channel . Therefore you really see a difference when you add that transform(). You should decide for yourself what is your logic and what you would like to do when there is the message in that channel. You may consider to use other channel types, but still consider to process messages somehow.
I have a simple IntegrationFlow sending SOAP messages with MarshallingWebServiceOutboundGateway. The deal is that, normally, the target service responds with empty message. It can of course return soap fault, but, on success, we expect an empty response. Now the problem is that if we get an empty response, SI recognizes it as "no response" and does not execute steps that are after the gateway in the IntegrationFlow. This happens even if gateway is set with setIgnoreEmptyResponses(false). According to documentation, it only works if it received an empty String, but response returned from the service is represented as null in my case.
I want to be able to continue the flow no matter if external service responds with empty or non-empty response. What would be the best way to achieve that?
EDIT1: It feels especially odd, because it stops execution of the IntegrationFlow even if both handlers are subscribed to publishSubscribeChannel (instead of being directly on the main flow). I would expect all subscribers to be executed unless the previous one produced an exception, but this is not what happens.
MarshallingWebServiceOutboundGateway outboundGateway = new MarshallingWebServiceOutboundGateway(
gatewaysUtils.buildOutboundUriToX(webServiceProperties.getServicePath()),
jaxb2Marshaller, messageFactory);
outboundGateway.setIgnoreEmptyResponses(false);
IntegrationFlows.from(channelName())
.transform(getKafkaMarshaller()::deserialize)
.handle(getOutboundGateway())
.handle(messageStatusRegistrator.registerMessageStatus())
.get();
EDIT2: Having tried the publishSubscribeChannel again, it worked this time around. It feels a bit hacky to me, but apparently it does work without any side-effects (for now). Fixed flow below. One thing to be careful about is scenario, when the service returns a non-empty, non-error response, which can potentially cause "output-channel or replychannel header available" if you do not provide the header or replyChannel explicitly.
IntegrationFlows.from(channelName())
.transform(getKafkaMarshaller()::deserialize)
.publishSubscribeChannel(channel -> channel
.subscribe(subflow -> subflow
.handle(getOutboundGateway()))
.subscribe(subflow -> subflow
.handle(messageStatusRegistrator::registerMessageStatus)))
.get();
I need to throttle the movement of messages between some JMS (activeMQ) queues to ensure I dont overrun an external service used during message processing.
I have done this in the past with Camel but given that this project is otherwise entirely Spring based, I figured I'd give spring-integration a whirl.
I am happy to see that in 5.0.7 the Java DSL is in core and would really like to use it instead of xml.
But...I cant seem to find good/current docs for using the DSL to do even simple things like create the input and output messageChannels for JMS.
Could anyone point me to any current example of using the java DSL to create channels that I can use to consume and produce messages with...and then later use in a bridge with some throttling applied?
Well, looks like our JMS chapter in the Reference Manual leaks of the Java DSL samples, similar to what we have so far with AMQP, for example:
https://docs.spring.io/spring-integration/docs/5.0.7.RELEASE/reference/html/amqp.html#_configuring_with_the_java_dsl_2
https://docs.spring.io/spring-integration/docs/5.0.7.RELEASE/reference/html/amqp.html#_configuring_with_the_java_dsl_4
I believe we can add similar paragraphs into the JMS chapter as well. Please, raise a JIRA on the matter and we will address it soon. Meanwhile I suggest you to open a org.springframework.integration.jms.dsl.Jms factory for appropriate builder to use.
On the other hand I can suggest you to take a look into the existing test-case of some possible configurations: https://github.com/spring-projects/spring-integration/blob/master/spring-integration-jms/src/test/java/org/springframework/integration/jms/dsl/JmsTests.java
For example to read from the queue you need a configuration like this:
#Bean
public IntegrationFlow jmsMessageDrivenFlow() {
return IntegrationFlows
.from(Jms.messageDrivenChannelAdapter(jmsConnectionFactory(), DefaultMessageListenerContainer.class)
.outputChannel(jmsMessageDrivenInputChannel())
.destination("jmsMessageDriven")
.configureListenerContainer(c -> c.clientId("foo")))
.<String, String>transform(String::toLowerCase)
.channel(jmsOutboundInboundReplyChannel())
.get();
}
To send to the JMS you need something like this:
#Bean
public IntegrationFlow jmsOutboundFlow() {
return f -> f
.handle(Jms.outboundAdapter(jmsConnectionFactory())
.destinationExpression("headers." + SimpMessageHeaderAccessor.DESTINATION_HEADER)
.configureJmsTemplate(t -> t.id("jmsOutboundFlowTemplate")));
}
I'm currently implementing a flow on a Spring Integration-based (ver. 3.0.1.RELEASE) application that requires to store messages on a JMS queue to be picked up later.
For that, I've been trying to use a Spring Integration JMS Inbound Channel Adapter with a custom selector, and then picking up the message from the queue by changing the JMS selector of the JMSDestinationPollingSource to some matching ID included as a header property.
One of the requirements for this is that I cannot add a new service or a JAVA method, so I've been trying to sort it out using a Control Bus, but keep receiving the same error when I send the message to set the messageSelector to something different.
Inbound Channel Adapter definition:
<int-jms:inbound-channel-adapter id="inboundAdapter"
channel="inboundChannel"
destinationName="bufferQueue"
connection-factory="connectionFactory"
selector="matchingID = 'NO VALUE'">
<int:poller fixed-delay="1000"/>
</int-jms:inbound-channel-adapter>
Message:
#'inboundAdapter.source'.setMessageSelector("matchingID = 'VALUE'")
Error:
EvaluationException: The method 'public void org.springframework.integration.jms.JmsDestinationPollingSource.setMessageSelector(java.lang.String)' is not supported by this command processor. If usign the Control Bus, consider adding #ManagedOperation or #ManagedAttribute.
Which, AFAIK, means that the JmsDestinationPollingSource class is not Control Bus manageable, as it's not passing the ControlBusMethodFilter.
Is this approach nonviable, or is there something I'm missing? Is there any way to set the selector dynamically using SI XML configuration files only?
First of all it is strange to use Java tool and don't allow to write code on Java...
But that is your choice, or as you said requirements.
Change the employer! ;-)
That's correct: Control Bus allows only #ManagedOperation and #ManagedAttribute method. Since JmsDestinationPollingSource.setMessageSelector. We can make it like that. But does it make so much sense if we can reach it a bit different approach?
<int:outbound-channel-adapter id="changeSelectorChannel"
ref"inboundAdapter.source method="setMessageSelector"/>
where a new selector expression should be as a payload of the Message to this channel.