Tracing input & output of message channels of Spring Integration - spring

I have build a small application using Spring Integration. I have also written some jUnit for more service and other classes.
I have used XML configuration for the channel and en-point configuration, I am wondering if I can test the input and output of a perticular channel.
Is there a way we can test the input and output of the channels?..
Update
I am trying to the below flow. How shall i proceed?
<int:channel id="getPresciption" />
<int:channel id="respPrescription" />
<int:channel id="storePrcedureChannell" />
<int-http:inbound-gateway
request-channel="getPresciption" reply-channel="respPrescription"
supported-methods="GET" path="/getAllPresciption">
<int-http:request-mapping
consumes="application/json" produces="application/json" />
</int-http:inbound-gateway>
<int:service-activator
ref="prescriptionServiceActivator" method="buildPrescription"
input-channel="getPresciption" output-channel="storePrcedureChannell" />
<int:service-activator
ref="prescriptionServiceActivator" method="storePrescription"
input-channel="storePrcedureChannell"></int:service-activator>
SO how can i write the Test contex?
Let below are the methods which are called by channel flow.
public Message<List<Prescription>> buildPrescription() {
//Do some processing
}
public Message<List<Prescription>> storePrescription(Message<List<Prescription>> msg) {
//Do something and return the List.
}

First of all you can take a look into the Spring Integration Testing Framework: https://docs.spring.io/spring-integration/reference/html/testing.html#test-context
And then use a MockIntegration.mockMessageHandler() together with the MockIntegrationContext.substituteMessageHandlerFor() to replace a real handler in the endpoint and verify incoming data from the channel.
If that is still hard for you, you always can inject those channels into your test class and add to them a ChannelInterceptor and verify messages in its preSend() implementation.

Related

Spring integration errorChannel, error handle

Scenario could be: my expectation could be 10 datapoint in batch, and I want to give response for {failed 5, pass 5} or sth.
my logic is to split the batch into data element and do validation.
successful validation will send to aggreagtor,
failed validation will throw error and pick up by error channel.
recipient-list-router take the errorChannel as inputChannel and 2 filter connect to it, the purpose is to filter some type of error to send response directly(eception unrelated to user input - server error or etc) and some type of client side error will go to aggregator to build response.
Is any problem with the logic?
My problem is I keep getting "Reply message received but the receiving thread has already received a reply" when build up the Result using service-activator after aggregator. this service-activator connect to replyChannel and it seems like there are some message already sent to this channel?
I checked my integration work flow only this service-activator and server error branch after "error filter" connect to replyChannel(but the handle is never called.)
Something wrong? BTW, can recipient-list-router or other type of endpoint connect to errorChannel? or it has to be service-activator as what I saw in all the example online?(but they are really simple example..)
Sample XML
<int:gateway id="myGateway" service-interface="someGateway" default-request-channel="splitChannel" error-channel="errorChannel" default-reply-channel="replyChannel" async-executor="MyThreadPoolTaskExecutor"/>
<int:splitter input-channel="splitChannel" output-channel="transformChannel" method="split">
<bean class="Splitter" />
</int:splitter>
<int:transformer id="transformer" input-channel="transformChannel" method="transform" output-channel="aggregateChannel">
<bean class="Transformer"/> // this may throw the validation error (filter_ErrorType_1), if it cannot transform
</int:transformer>
<int:aggregator id="aggregator"
input-channel="aggregateChannel"
output-channel="createAnswerChannel"
method="aggregate">
<bean class="MyAggregator" />
</int:aggregator>
<int:recipient-list-router id="myErrorRouter" input-channel="errorChannel">
<int:recipient channel="filter_ErrorType_1"/>
<int:recipient channel="filter_ErrorType_2"/>
<int:recipient channel="filter_ErrorType_3"/>
</int:recipient-list-router>
<int:filter input-channel="filter_ErrorType_1" output-channel="aggregateChannel" method="accept"></int:filter>
<int:filter input-channel="filter_ErrorType_2" output-channel="createErrorAnswerChannel" method="accept"></int:filter>
<int:filter input-channel="filter_ErrorType_3" output-channel="createErrorAnswerChannel" method="accept"></int:filter>
<int:service-activator input-channel='createErrorAnswerChannel' output-channel="replyChannel" method='buildError'>
<bean class="AnswerBuilder"/>
</int:service-activator>
<int:service-activator input-channel='createAnswerChannel' output-channel="replyChannel" method='build'>
<bean class="AnswerBuilder"/>
</int:service-activator>
Follow up:
<int:gateway id="myGateway" service-interface="someGateway" default-request-channel="splitChannel" error-channel="errorChannel" default-reply-channel="replyChannel" async-executor="MyThreadPoolTaskExecutor"/>
<int:splitter input-channel="splitChannel" output-channel="transformChannel" method="split">
<bean class="Splitter" />
</int:splitter>
<int:transformer id="transformer1" input-channel="toTransformer1" method="transform" output-channel="toTransformer2">
<bean class="Transformer1"/> // this may throw the validation error (filter_ErrorType_1), if it cannot transform
</int:transformer>
<int:transformer id="transformer2" input-channel="toTransformer2" method="transform" output-channel="toTransformer3">
<bean class="Transformer2"/> // this may throw the validation error (filter_ErrorType_2), if it cannot transform
</int:transformer>
<int:transformer id="transformer3" input-channel="toTransformer3" method="transform" output-channel="aggregateChannel">
<bean class="Transformer3"/> // this may throw the validation error (filter_ErrorType_3), if it cannot transform
</int:transformer>
???
// seems like you are proposing to have one gateway for each endpoint that may throw error.
// but in this case, take transfomer 1 for example, I cannot output the gateway directly to aggregate channel since for valid data it has to go to transformer 2
// but the failed message throwed by the error handler cannot pass transformer 2 because of afterall this is a error message not a valid data for transformer 2
// <int:service-activator input-channel="toTransformer1" output-channel="toTransformer2" ref="gateway1"/>
// <int:gateway id="gateway1" default-request-channel="toTransformer1" error-channel="errorChannel1"/>
// <int:transformer id="transformer" input-channel="toTransformer1" method="transform">
// <bean class="Transformer"/> // this may throw the validation error (filter_ErrorType_1), if it cannot transform
// </int:transformer>
// how to deal with this problem?
<int:service-activator input-channel='createErrorAnswerChannel' output-channel="replyChannel" method='buildError'>
<bean class="AnswerBuilder"/>
</int:service-activator>
<int:service-activator input-channel='createAnswerChannel' output-channel="replyChannel" method='build'>
<bean class="AnswerBuilder"/>
</int:service-activator>
I actually have complicated logic inside but I use transformer 123 to represent here.
Your question isn't clear. Please,be sure in the future provide more concrete info. Some config and StackTrace or logs are useful, too.
I guess that you have in the beginning of your flow <gateway> with configured error-channel. That's why you are receiving Reply message received but the receiving thread has already received a reply.
But I can't be sure, because there is no those words in your question. Right?
You can't rely on the errorChannel header there and come back for the reply eventually because the errorChannel header in case of Gateway is the same as replyChannel, and it is TemporaryReplyChannel - one-shot-usage channel and only for receive() operation.
Since we don't have any configuration or code from you we can't help you properly.
I suppose you need a middle-flow gateway via service-activator:
<service-activator id="gatewayTestService" input-channel="inputChannel"
output-channel="outputChannel" ref="gateway"/>
<gateway id="gateway" default-request-channel="requestChannel" error-channel="myErrorChannel"/>
or <chain> with <gateway> to perform validation and catch errors only there and return a desired reply for failures. That service-activator will be able to send them all to the <aggregator> afterward. In this case the <aggregator> can reply back to the gateway properly.
EDIT
errorChannel is a name for default global bean to catch any error messages from any Integration place. See more info in the http://docs.spring.io/spring-integration/reference/html/configuration.html#namespace-errorhandler.
So, that name is fully bad for your use case , because that myErrorRouter is going to handle ALL the errors!
The <int:recipient-list-router> sends message to all its recipients if it passes a selector or if there is no selector.
You don't need default-reply-channel on the <gateway> if it isn't publish-subscribe. You can just rely on the replyChannel header, which works if there is no output-channel defined.
What I'm talking about <service-activator> and <gateway> is pretty straight forward in front of your <transformer> after <splitter>:
<int:service-activator input-channel="transformChannel"
output-channel="aggregateChannel" ref="gateway"/>
<int:gateway id="gateway" default-request-channel="transformChannel" error-channel="validationErrorChannel"/>
<int:transformer id="transformer" input-channel="transformChannel" method="transform">
<bean class="Transformer"/> // this may throw the validation error (filter_ErrorType_1), if it cannot transform
</int:transformer>
So, splitter sends items to the service-activator. That one proceeds with the message to the gateway around transformer with custom error-channel exactly for one item. The transformer answers to the replyChannel exactly to that previous gateway. If it throws some Exception, it is handled by the validationErrorChannel process. Which should reply with some compensation message. That message is bubbled to the service-activator. Finally service-activator sends a result to the aggregateChannel. And it is black box for the service-activator if validation was good or not.
Hope that helps a bit.
EDIT2
I'm disappointed that you haven't accepted my advises in your code, but nevertheless that is how I see it:
<int:gateway id="myGateway" service-interface="someGateway" default-request-channel="splitChannel"
async-executor="MyThreadPoolTaskExecutor" />
<int:splitter input-channel="splitChannel" output-channel="transformChannel" method="split">
<bean class="Splitter" />
</int:splitter>
<int:service-activator input-channel="validateChannel" output-channel="aggregateChannel"
ref="validateGateway"/>
<gateway id="validateGateway" default-request-channel="toTransformer1" error-channel="myErrorChannel"/>
<chain input-channel="toTransformer1">
<int:transformer method="transform">
<bean class="Transformer1" />
</int:transformer>
<int:transformer method="transform">
<bean class="Transformer2" />
</int:transformer>
<int:transformer method="transform">
<bean class="Transformer3" />
</int:transformer>
</chain>
<int:service-activator input-channel="myErrorChannel" method="buildError">
<bean class="AnswerBuilder" />
</int:service-activator>
<int:aggregator id="aggregator"
input-channel="aggregateChannel"
output-channel="createAnswerChannel"
method="aggregate">
<bean class="MyAggregator" />
</int:aggregator>
<int:service-activator input-channel='createAnswerChannel' method='build'>
<bean class="AnswerBuilder" />
</int:service-activator>
Pay attention, how I chain transformers. So, you have one gateway for all your transformers and any error on any of them will be thrown to the gateway for error handling on the myErrorChannel.

Problems with unit testing a spring integration program

I am trying to unit test an xpath router, but having problems with it. here is my context file:
<int:channel id="toTransactionTypeRouterChannel" />
<int-xml:xpath-router id="transactionsTypeRouter"
input-channel="toTransactionTypeRouterChannel" resolution-required="false"
evaluate-as-string="true" default-output-channel="errorChannel">
<!-- Select node name of the first child -->
<int-xml:xpath-expression
expression="name(/soapNs:Envelope/soapNs:Body/schNs:processArchiveRequest/schNs:fulfillmentRequest/schNs:requestDetail/*[1])"
namespace-map="archiveNamespaceMap" />
<int-xml:mapping value="sch:bulkRequestDetail"
channel="bulkChannel" />
<int-xml:mapping value="sch:transactionalRequestDetail"
channel="transactionChannel" />
</int-xml:xpath-router>
<int:channel id="bulkChannel" />
<int:channel id="transactionChannel" />
<int:transformer input-channel="bulkChannel"
output-channel="consoleOut" expression="'Bulk channel has received the payload' " />
<int:transformer input-channel="transactionChannel"
output-channel="consoleOut" expression="'Transaction channel has received payload' " />
<int:transformer input-channel="errorChannel"
output-channel="consoleOut" expression="'Error channel has received payload' " />
As you can see here, there are 2 different routes(bulk,trans.) + error channel.Here is my unit test case for trans channel route:
#Test
public void testTransactionFlow() throws Exception {
try {
Resource bulkRequest = new FileSystemResource("src/main/resources/mock-message-examples/SampleProcessArchiveTransRequest.xml");
String transRequestStr= extractResouceAsString(bulkRequest);
toTransactionTypeRouterChannel.send(MessageBuilder.withPayload(transRequestStr).build());
Message<?> outMessage = testChannel.receive(0);
assertNotNull(outMessage);
context file for junit
<int:bridge input-channel="transactionChannel"
output-channel="testChannel"/>
<int:channel id="testChannel">
<int:queue/>
</int:channel>
As you can see, in the junit context file, I am connecting transactional channel to the test channel.in the junit test case, I am sending a payload to the router in the junit method, and trying to receive it from the input channel and use it for assertion. however the assertion fails, as the message from transaction channel directly goes to consoleOut before getting routed to inputChannel as given in the junit coontext file. How do I intercept the message before it goes to consoleOut? I also tried adding wireTap interceptors but they didnt work:
WireTap wireTap = new WireTap(someChannel);
boolean w = wireTap.isRunning();
transactionChannel.addInterceptor(wireTap);
Basically, I need a separate flow for unit testing.
With that configuration, you are just adding a second consumer to transactionChannel - messages will be round-robin distributed to the transformer and bridge.
You can unsubscribe the transformer for your test case by autowiring it by id as an EventDrivenConsumer and stop() it before sending your message.

DeferredResult from JMS Request/Reply with ListenableFuture

I was looking for opportunities to improve the Rest Api we have exposed to external clients. During that exercise, I found I am barely taking advantage of the decision our integration team took to have backend integrations with JMS request/reply instead of traditional blocking SOAP request/reply.
Currently all the interactions to message broker are done using jmsOutboundGateway, because of which requesting thread has to wait for completion. In order to scale RestAPI, I want to send JMS reply using DeferredResult from Spring MVC controller. The controller interaction with message broker is depicted below:
Controller --> GatewayProxy --> JMSOutboundGateway
I am looking for opportunities to use ListenableFuture as return type of GatewayProxy, but I am unable to find a proper mean of achieving it using spring integration.
Below is the integration flow I am calling from controller:
<int:gateway
service-interface="ae.emaratech.ngx.service.PermitSearchService"
default-request-channel="permit_search_input_channel"
default-reply-timeout="${broker.jms.gateway.min.consumers}"/>
<int:channel id="permit_search_input_channel" />
<int:chain input-channel="permit_search_input_channel">
<int:header-enricher>
<int:header name="person_number" expression="payload"/>
</int:header-enricher>
<int:transformer expression="#formatString(#api_messages['FIND_PERM_BY_PERSNO_MSG'],headers)"/>
<int:header-filter header-names="JMS_*,jms_*,priority" pattern-match="true" />
<int:header-enricher>
<int:header name="jms_type" type="java.lang.String" value="1" overwrite="true"/>
</int:header-enricher>
<jms:outbound-gateway
request-destination="permitsInboundQueue"
reply-destination="permitsOutboundQueue"
receive-timeout="${broker.jms.gateway.timeout}"
correlation-key="Correlation_ID"
connection-factory="brokerConnectionFactory">
<jms:reply-listener concurrent-consumers="${broker.jms.gateway.min.consumers}" max-concurrent-consumers="${broker.jms.gateway.max.consumers}"/>
</jms:outbound-gateway>
<int-xml:xpath-filter throw-exception-on-rejection="true">
<int-xml:xpath-expression expression="not(boolean(/*/ErrorDetails))"/>
</int-xml:xpath-filter>
<int-xml:xslt-transformer
xsl-resource="classpath:/META-INF/spring/integration/permit-to-json.xsl"
result-type="StringResult" >
</int-xml:xslt-transformer>
<int:transformer expression="payload.toString()"/>
</int:chain>
Not sure what problem you have, but the feature looks like:
ListenableFuture<String> result = this.asyncGateway.async("foo");
result.addCallback(new ListenableFutureCallback<String>() {
#Override
public void onSuccess(String result) {
...
}
#Override
public void onFailure(Throwable t) {
...
}
});
It is available since version 4.1.

Spring integration chain error handling

Need help in error handling in a chain during splitter and aggregator flow for a synchronous channel.
Below is the Use case and it will be synchronous channel. So in the chain there will be a set of service activator to perform the business logic. Now if there is any exception in the service activator present in the chain, I want that to be handled in the chain itself and continue with the other splitted messages.
Inorder to do that, I have tried adding header enricher for error handler in the chain.But did not work. Any suggestion.
Object1 contains List < Object2 >
Flow:
List < Object1 > --> Splitter1 (for Object1) --> Splitter2 (for Object2) --> Chain --> Aggregator --> Aggregator
Code
<int:chain input-channel="ch3" output-channel="ch10" >
<int:header-enricher>
<int:error-channel ref="exception1" ></int:error-channel>
</int:header-enricher>
<int:service-activator ref="myService" method="method1"></int:service-activator>
<int:service-activator ref="myService" method="method2"></int:service-activator>
<int:service-activator ref="myService" method="method3"></int:service-activator>
<int:service-activator ref="myService" method="method4"></int:service-activator>
</int:chain>
<!-- Exception channel for chain and the output should go to the chain output channel -->
<int:chain input-channel="exception1" output-channel="ch10" >
<int:service-activator ref="exp" method="myException"></int:service-activator>
</int:chain>
Unfortunately it doesn't work that way. The error-channel header is for the asynchronous cases, too. It allows to override the default behavior in the MessagePublishingErrorHandler for PollableChannel and channels with Executor. In other words when we really can't do try...catch if talk in raw Java words.
So, to fix your requirements you really should rely on the try...catch function for that particular <service-activator>. It is called like ExpressionEvaluatingRequestHandlerAdvice and must be configured as on the <request-handler-advice-chain>.
In your case you should configure that Advice like:
<bean class="ExpressionEvaluatingRequestHandlerAdvice">
<property name="trapException" value="true"/>
<property name="onFailureExpression" value="#exception"/>
<property name="failureChannel" value="myErrorChannel"/>
</bean>
The trapException="true" allows do not re-throw the exception to the top level. In your case to the <splitter>.
The onFailureExpression says what to send to the failureChannel from the catch block.
The failureChannel is your desired error-channel to handle <service-activator> failures.
The source code looks like, by the way:
try {
Object result = callback.execute();
if (this.onSuccessExpression != null) {
this.evaluateSuccessExpression(message);
}
return result;
}
catch (Exception e) {
Exception actualException = this.unwrapExceptionIfNecessary(e);
if (this.onFailureExpression != null) {
Object evalResult = this.evaluateFailureExpression(message, actualException);
if (this.returnFailureExpressionResult) {
return evalResult;
}
}
if (!this.trapException) {
throw actualException;
}
return null;
}
Since we prevent re-throw with trapException="true", we end up on the return null. And having <service-activator> with null-payload loyalty we allow our <splitter> to go ahead with other messages.
HTH

how to write output channel from itemWriter in spring batch and spring integration?

firstly thanks for attention, i combined spring batch and spring integration, i defined a job flow and retrieve files from ftp adapter and sent to jobChannel, and process on it with spring batch , i want to write to output channel and consume the channel after processing, my code is:
<int-ftp:outbound-gateway id="gatewayGET"
local-directory-expression="'./backup/' +#remoteDirectory"
session-factory="ftpSessionFactory"
request-channel="toGetChannel"
reply-channel="toProcessChannel"
command="get"
temporary-file-suffix=".writing"
command-options="-P"
expression="payload.remoteDirectory + '/' + payload.filename"/>
<int:channel id="toProcessChannel">
<int:interceptors>
<int:wire-tap channel="logger2"/>
</int:interceptors>
</int:channel>
<int:channel id="outboundJobRequestChannel"/>
<int:channel id="replyJobChannel"/>
<service-activator input-channel="jobLaunchReplyChannel"/>
<int:transformer input-channel="toProcessChannel" output-channel="outboundJobRequestChannel">
<bean class="ir.isc.macna.configuration.FileMessageToJobRequest">
<property name="fileParameterName" value="fileName"/>
</bean>
</int:transformer>
<batch-int:job-launching-gateway request-channel="outboundJobRequestChannel"
reply-channel="jobLaunchReplyChannel"/>
and my writer code is:
#Component
#StepScope
public class MacnaFileWriter implements ChunkMessageChannelItemWriter<FileInfo> {
#Autowired
#Qualifier("replyJobChannel")
private MessageChannel messageChannel;
#Override
public void write(List<? extends FileInfo> list) throws Exception {
// send Message to replyJobChannel channel with Send method
}
}
and use ftp adapter to write files on the server:
<int-ftp:outbound-gateway session-factory="ftpSessionFactory"
request-channel="replyJob"
command="mput"
auto-create-directory="true"
expression="payload"
remote-directory-expression="payload.remoteDirectory + '/' + payload.filename + '.out'"
reply-channel="output"/>
Is this standard way to run batch job and consume result?
MessageChannel has send method. For this purpose you can use MessageBuilder to create a Message<?> for your payload.
Since it is just a <channel> there is no difference with any other MessageChannel to consume. The standard way define a consumer like this:
<service-activator input-channel="jobLaunchReplyChannel"/>
However it isn't clear why you are going to send messages to the jobLaunchReplyChannel, when this channel is specific for the result from <batch-int:job-launching-gateway> (JobLaunchingGateway class):
jobExecution = this.jobLaunchingMessageHandler.launch(jobLaunchRequest);
So, that jobExecution is sent to the jobLaunchReplyChannel.
See Spring Batch Integration Documentation.
Maybe do you need AsyncItemWriter or ChunkMessageChannelItemWriter?

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