CODEWITHSUNDEEP
spring-integration
Narasimha
Narasimha

Reputation: 15

Why returning Transformer null throws exception?

Transformer throws exception for returning null. I'm getting the message payload and doing my business logic in transformer. Then, sending response to fileoutput channel. I've tried using .handle method too instead of transformer, but getting one way message exception. EDIT

 @Bean
 IntegrationFlow integrationFlow() {
return IntegrationFlows.from(this.sftpMessageSource()).channel(fileInputChannel()).
        handle(service, "callMethod").channel(fileOutputChannel()).
        handle(orderOutMessageHandler()).get();

}

EDIT 2

[ERROR] 2020-06-14 14:49:48.053 [task-scheduler-9] LoggingHandler - java.lang.AbstractMethodError: Method org/springframework/integration/sftp/session/SftpSession.getHostPort()Ljava/lang/String; is abstract
at org.springframework.integration.sftp.session.SftpSession.getHostPort(SftpSession.java)
at org.springframework.integration.file.remote.session.CachingSessionFactory$CachedSession.getHostPort(CachingSessionFactory.java:295)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizer.copyFileToLocalDirectory(AbstractInboundFileSynchronizer.java:496)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizer.copyIfNotNull(AbstractInboundFileSynchronizer.java:400)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizer.transferFilesFromRemoteToLocal(AbstractInboundFileSynchronizer.java:386)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizer.lambda$synchronizeToLocalDirectory$0(AbstractInboundFileSynchronizer.java:349)
at org.springframework.integration.file.remote.RemoteFileTemplate.execute(RemoteFileTemplate.java:437)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizer.synchronizeToLocalDirectory(AbstractInboundFileSynchronizer.java:348)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizingMessageSource.doReceive(AbstractInboundFileSynchronizingMessageSource.java:265)
at org.springframework.integration.file.remote.synchronizer.AbstractInboundFileSynchronizingMessageSource.doReceive(AbstractInboundFileSynchronizingMessageSource.java:66)
at org.springframework.integration.endpoint.AbstractFetchLimitingMessageSource.doReceive(AbstractFetchLimitingMessageSource.java:45)
at org.springframework.integration.endpoint.AbstractMessageSource.receive(AbstractMessageSource.java:167)
at org.springframework.integration.endpoint.SourcePollingChannelAdapter.receiveMessage(SourcePollingChannelAdapter.java:250)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.doPoll(AbstractPollingEndpoint.java:359)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.pollForMessage(AbstractPollingEndpoint.java:328)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.lambda$null$1(AbstractPollingEndpoint.java:275)
at org.springframework.integration.util.ErrorHandlingTaskExecutor.lambda$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$2(AbstractPollingEndpoint.java:272)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
at java.util.concurrent.FutureTask.run(FutureTask.java)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Upvotes: 0

Views: 625

Answers (1)

Artem Bilan
Artem Bilan

Reputation: 121337

The transformer is designed to always return a reply because it is a transformation operation. Therefore you can’t return null from your method . You get one-way error probably because your handle method is void.

Upvotes: 2

Related Questions