Using an ExpressionEvaluatingRequestHandlerAdvice in a split/aggregate integration flow - spring-integration

Question

I'm looking to implement an integration flow where at some point a split/aggregate writes a bunch of files, returning true or false if an exception occurred in writing one of the files.
It works fine when all files are written without error, I get a list full of trues and can validate my business logic.
I've tried to use a ExpressionEvaluatingRequestHandlerAdvice to get a false when writing one the files failed (regardless of the details of the failure), to no avail:
#Bean
public IntegrationFlow mainFlow() {
return IntegrationFlows.from(...)
...
.split()
.<MyClass, Boolean>route(pp -> pp.getPattern == null,
mm -> mm.subFlowMapping(true, aSubflow()))
.subFlowMapping(false, anotherSubflow()))
// the following line works when I don't use an advice, but does not handle exceptions from above
//.handle((p, h) -> true)
.aggregate()
.<List<Boolean>>handle((p, h) -> p.stream().allMatch(b -> b))
...
.get();
}
public IntegrationFlow aSubflow() {
return f -> f.handle(Files.outboundGateway(...),
c -> c.advice(fileSystemAdvice()));
}
#Bean
public Advice advice() {
var advice = new ExpressionEvaluatingRequestHandlerAdvice();
advice.setSuccessChannelName("filesystemSuccess.input");
advice.setOnSuccessExpressionString("payload + ' was successful'");
advice.setFailureChannelName("filesystemFailure.input");
advice.setOnFailureExpressionString("payload + ' failed'");
advice.setTrapException(true);
return advice;
}
#Bean
public IntegrationFlow success() {
// logging works fine, but that's not what I want
//return f -> f.handle(System.out::println);
return f -> f.handle((p, h) -> true);
}
#Bean
public IntegrationFlow failure() {
// logging works fine
//return f -> f.handle(System.out::println);
return f -> f.handle((p, h) -> false);
}
With this configuration, I get the a DestinationResolutionException no output-channel or replyChannel header available.
What's the correct way to branch the outbound of the success/failure flows back to the split/aggregate flow (just before the aggregate)?
UPDATE:
I also tried to use a gateway as mentioned in the documentation (the splitRouteAggregate() example), but still get the same exception.
UPDATE #2
Here is a minimal failing example: no route, no subflow, just moving a file:
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Bean
public IntegrationFlow myFlow() {
return IntegrationFlows
.from(Files.inboundAdapter(new File("./")).patternFilter("dummy.txt")
.autoCreateDirectory(true).recursive(false)
.useWatchService(true).watchEvents(FileReadingMessageSource.WatchEventType.CREATE))
.handle(Files.outboundGateway(new File("./out"))
.deleteSourceFiles(true)
.fileExistsMode(FileExistsMode.REPLACE)
.autoCreateDirectory(false),
c -> c.advice(advice())
)
.<Object, Boolean>transform(p -> !Boolean.FALSE.equals(p))
.log(LoggingHandler.Level.INFO, m -> m.getHeaders().getId() + ": " + m.getPayload())
.get();
}
#Bean
public Advice advice() {
var advice = new ExpressionEvaluatingRequestHandlerAdvice();
advice.setOnFailureExpressionString("false");
return advice;
}
}
Create the out directory at the root of the project, run the project, and then create a dummy.txt at the root of the project, it works fine (though I get two lines of log and not one as I expected).
2022-09-16 23:55:23.678 INFO 21564 --- [ scheduling-1] o.s.integration.handler.LoggingHandler : 1d253af9-625a-3745-edbb-0438224a9163: true
2022-09-16 23:55:23.700 INFO 21564 --- [ scheduling-1] o.s.integration.handler.LoggingHandler : 9d2486fc-f776-a5c7-fb21-f16b9ced3094: true
Now, create the out directory at the root of the project, run the project, rmdir the out directory, and then create a dummy.txt at the root of the project, to force an IllegalArgumentException when trying to write the file. I don't get a false payload, the workflow is interrupted by the exception.
2022-09-17 21:19:00.895 ERROR 14548 --- [ scheduling-1] o.s.integration.handler.LoggingHandler : org.springframework.messaging.MessageHandlingException: error occurred in message handler [bean 'myFlow.file:outbound-gateway#0' for component 'myFlow.org.springframework.integration.config.ConsumerEndpointFactoryBean#0'; defined in: 'integrationtest.Application'; from source: 'bean method myFlow']; nested exception is java.lang.IllegalArgumentException: Destination directory [.\out] does not exist., failedMessage=GenericMessage [payload=C:\Users\*****\Dev\ldd\so73745736\.\dummy.txt, headers={file_originalFile=C:\Users\*****\Dev\ldd\so73745736\.\dummy.txt, id=909a6ffe-6598-da35-33ff-90ebb9c68d67, file_name=dummy.txt, file_relativePath=dummy.txt, timestamp=1663442340858}]
at org.springframework.integration.support.utils.IntegrationUtils.wrapInHandlingExceptionIfNecessary(IntegrationUtils.java:191)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:65)
at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:115)
at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:133)
at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:106)
at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:72)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:317)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:272)
at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:187)
at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:166)
at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:47)
at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:109)
at org.springframework.integration.endpoint.SourcePollingChannelAdapter.handleMessage(SourcePollingChannelAdapter.java:196)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.messageReceived(AbstractPollingEndpoint.java:475)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.doPoll(AbstractPollingEndpoint.java:461)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.pollForMessage(AbstractPollingEndpoint.java:413)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.lambda$createPoller$4(AbstractPollingEndpoint.java:348)
at org.springframework.integration.util.ErrorHandlingTaskExecutor.lambda$execute$0(ErrorHandlingTaskExecutor.java:57)
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50)
at org.springframework.integration.util.ErrorHandlingTaskExecutor.execute(ErrorHandlingTaskExecutor.java:55)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.lambda$createPoller$5(AbstractPollingEndpoint.java:341)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:95)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.IllegalArgumentException: Destination directory [.\out] does not exist.
at org.springframework.util.Assert.isTrue(Assert.java:139)
at org.springframework.integration.file.FileWritingMessageHandler.validateDestinationDirectory(FileWritingMessageHandler.java:496)
at org.springframework.integration.file.FileWritingMessageHandler.evaluateDestinationDirectoryExpression(FileWritingMessageHandler.java:884)
at org.springframework.integration.file.FileWritingMessageHandler.handleRequestMessage(FileWritingMessageHandler.java:510)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler$AdvisedRequestHandler.handleRequestMessage(AbstractReplyProducingMessageHandler.java:208)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.integration.handler.advice.AbstractRequestHandlerAdvice$CallbackImpl.execute(AbstractRequestHandlerAdvice.java:151)
at org.springframework.integration.handler.advice.ExpressionEvaluatingRequestHandlerAdvice.doInvoke(ExpressionEvaluatingRequestHandlerAdvice.java:215)
at org.springframework.integration.handler.advice.AbstractRequestHandlerAdvice.invoke(AbstractRequestHandlerAdvice.java:67)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215)
at jdk.proxy2/jdk.proxy2.$Proxy46.handleRequestMessage(Unknown Source)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.doInvokeAdvisedRequestHandler(AbstractReplyProducingMessageHandler.java:155)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:139)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:56)
... 27 more

Answer 1

The logic of the ExpressionEvaluatingRequestHandlerAdvice is like this:
#Override
protected Object doInvoke(ExecutionCallback callback, Object target, Message<?> message) {
try {
Object result = callback.execute();
if (this.onSuccessExpression != null) {
evaluateSuccessExpression(message);
}
return result;
}
catch (RuntimeException e) {
Exception actualException = unwrapExceptionIfNecessary(e);
if (this.onFailureExpression != null) {
Object evalResult = evaluateFailureExpression(message, actualException);
if (this.returnFailureExpressionResult) {
return evalResult;
}
}
if (!this.trapException) {
if (e instanceof ThrowableHolderException) { // NOSONAR
throw (ThrowableHolderException) e;
}
else {
throw new ThrowableHolderException(actualException); // NOSONAR lost stack trace
}
}
return null;
}
}
So, if callback.execute() is OK, we try to call an onSuccessExpression (if any) and still return the result of the callback.execute(). Looks like in your case it is whatever an HTTP call replies. I don't think we need this onSuccessExpression to return just true. We can do that a bit later with a transform(). Stay tuned.
If callback.execute() fails, we call onFailureExpression, which in your case could be as simple as: setOnFailureExpressionString("false").
Therefore your advice should be configured like this:
#Bean
public Advice advice() {
var advice = new ExpressionEvaluatingRequestHandlerAdvice();
advice.setOnFailureExpressionString("false");
advice.setReturnFailureExpressionResult(true);
return advice;
}
Now, after that Http.outboundGateway() and before an aggregator, you have to add just this:
.<Object, Boolean>transform(p -> !Boolean.FALSE.equals(p))