How to test ApplicationEvent in Spring Integration Flow - kotlin

Question

In my Spring project(WebFlux/Kotlin Coroutines/Java 17), I defined a bean like this.
#Bean
fun sftpInboundFlow(): IntegrationFlow {
return IntegrationFlows
.from(
Sftp.inboundAdapter(sftpSessionFactory())
.preserveTimestamp(true)
.deleteRemoteFiles(true) // delete files after transfer is done successfully
.remoteDirectory(sftpProperties.remoteDirectory)
.regexFilter(".*\\.csv$")
// local settings
.localFilenameExpression("#this.toUpperCase() + '.csv'")
.autoCreateLocalDirectory(true)
.localDirectory(File("./sftp-inbound"))
) { e: SourcePollingChannelAdapterSpec ->
e.id("sftpInboundAdapter")
.autoStartup(true)
.poller(Pollers.fixedDelay(5000))
}
/* .handle { m: Message<*> ->
run {
val file = m.payload as File
log.debug("payload: ${file}")
applicationEventPublisher.publishEvent(ReceivedEvent(file))
}
}*/
.transform<File, DownloadedEvent> { DownloadedEvent(it) }
.handle(downloadedEventMessageHandler())
.get()
}
#Bean
fun downloadedEventMessageHandler(): ApplicationEventPublishingMessageHandler {
val handler = ApplicationEventPublishingMessageHandler()
handler.setPublishPayload(true)
return handler
}
And write a test for asserting the application event.
#OptIn(ExperimentalCoroutinesApi::class)
#SpringBootTest(
classes = [SftpIntegrationFlowsTestWithEmbeddedSftpServer.TestConfig::class]
)
#TestPropertySource(
properties = [
"sftp.hostname=localhost",
"sftp.port=2222",
"sftp.user=user",
"sftp.privateKey=classpath:META-INF/keys/sftp_rsa",
"sftp.privateKeyPassphrase=password",
"sftp.remoteDirectory=${SftpTestUtils.sftpTestDataDir}",
"logging.level.org.springframework.integration.sftp=TRACE",
"logging.level.org.springframework.integration.file=TRACE",
"logging.level.com.jcraft.jsch=TRACE"
]
)
#RecordApplicationEvents
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
class SftpIntegrationFlowsTestWithEmbeddedSftpServer {
companion object {
private val log = LoggerFactory.getLogger(SftpIntegrationFlowsTestWithEmbeddedSftpServer::class.java)
}
#Configuration
#Import(
value = [
SftpIntegrationFlows::class,
IntegrationConfig::class
]
)
#ImportAutoConfiguration(
value = [
IntegrationAutoConfiguration::class
]
)
#EnableConfigurationProperties(value = [SftpProperties::class])
class TestConfig {
#Bean
fun embeddedSftpServer(sftpProperties: SftpProperties): EmbeddedSftpServer {
val sftpServer = EmbeddedSftpServer()
sftpServer.setPort(sftpProperties.port ?: 22)
//sftpServer.setHomeFolder()
return sftpServer
}
#Bean
fun remoteFileTemplate(sessionFactory: SessionFactory<LsEntry>) = RemoteFileTemplate(sessionFactory)
}
#Autowired
lateinit var uploadGateway: UploadGateway
#Autowired
lateinit var embeddedSftpServer: EmbeddedSftpServer
#Autowired
lateinit var template: RemoteFileTemplate<LsEntry>
#Autowired
lateinit var applicationEvents: ApplicationEvents
#BeforeAll
fun setup() {
embeddedSftpServer.start()
}
#AfterAll
fun teardown() {
embeddedSftpServer.stop()
}
#Test
//#Disabled("application events can not be tracked in this integration tests")
fun `download the processed ach batch files to local directory`() = runTest {
val testFilename = "foo.csv"
SftpTestUtils.createTestFiles(template, testFilename)
eventually(10.seconds) {
// applicationEvents.stream().forEach{ log.debug("published event:$it")}
applicationEvents.stream(DownloadedEvent::class.java).count() shouldBe 1
SftpTestUtils.fileExists(template, testFilename) shouldBe false
SftpTestUtils.cleanUp(template)
}
}
}
It can not catch the application events by ApplicationEvents.
I tried to replace the ApplicationEventPublishingMessageHandler with a constructor autowired ApplicationEventPublisher, it also does not work as expected.
Check the complete test source codes: SftpIntegrationFlowsTestWithEmbeddedSftpServer
Update: The applicationEvents does not work in an async thread, either applying a #Async on the listener method or invoking applicationEvents in a async thread, the application event records did not work as expected.

Answer 1

I'm not familiar with that #RecordApplicationEvents, so I would register an #EventListener(File payload) in the support #Configuration with some async barrier to wait form an event from that scheduled task.
You can turn on a DEBUG logging for org.springframework.integration and Message History to see in logs how your message travels. If there is one at all according to your SFTP state.