No remote path exception when upgrading to Spring Integration Sftp 6.0

[hantsy]

Spring Integration Sftp 6.0/Spring Boot 3.0/Java 17/Kotlin 1.7.22

We have upgraded our project from Spring Boot 2.7.5 to Spring Boot 3.0. Some functions of the Spring Integration Sftp is broken.

In integration 6.0 Sftp, it uses Apache SSHD instead of the legacy jsch.

There is a IntegrationFlow to list remote files.

  @Bean
  fun listSftpFolderOutboundFlow(sftpSessionFactory: SessionFactory<SftpClient.DirEntry>): IntegrationFlow =
      IntegrationFlow
          .from("listSftpChannel")
          .handle(
              Sftp.outboundGateway(sftpSessionFactory, AbstractRemoteFileOutboundGateway.Command.LS, "payload")
                  .options(AbstractRemoteFileOutboundGateway.Option.RECURSIVE)
          )
          .transform<List<SftpFileInfo>, List<String>> { it.map { s -> s.toString() }.toList() }
          .channel("replyListSftpChannel")
          .get()

It worked well in integration 5/Spring 2.7.5. When passing an empty string as the message payload, it will display all files in the sftp user home root folder.

But when upgraded to integration 6.0, it will throw the exception.

java.lang.IllegalArgumentException: No remote path
	at org.apache.sshd.common.util.ValidateUtils.createFormattedException(ValidateUtils.java:213)
	at org.apache.sshd.common.util.ValidateUtils.throwIllegalArgumentException(ValidateUtils.java:179)
	at org.apache.sshd.common.util.ValidateUtils.checkTrue(ValidateUtils.java:156)
	at org.apache.sshd.common.util.ValidateUtils.checkNotNullAndNotEmpty(ValidateUtils.java:56)
	at org.apache.sshd.sftp.client.impl.SftpIterableDirEntry.<init>(SftpIterableDirEntry.java:44)
	at org.apache.sshd.sftp.client.impl.AbstractSftpClient.readDir(AbstractSftpClient.java:1153)
	at org.springframework.integration.sftp.session.SftpSession.doList(SftpSession.java:99)
	at org.springframework.integration.sftp.session.SftpSession.list(SftpSession.java:69)
	at org.springframework.integration.sftp.session.SftpSession.list(SftpSession.java:52)
	at org.springframework.integration.file.remote.session.CachingSessionFactory$CachedSession.list(CachingSessionFactory.java:227)
	at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.listFilesInRemoteDir(AbstractRemoteFileOutboundGateway.java:993)
	at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.ls(AbstractRemoteFileOutboundGateway.java:958)
	at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.lambda$doLs$6(AbstractRemoteFileOutboundGateway.java:608)
	at org.springframework.integration.file.remote.RemoteFileTemplate.execute(RemoteFileTemplate.java:452)
	at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.doLs(AbstractRemoteFileOutboundGateway.java:607)
	at org.springframework.integration.file.remote.gateway.AbstractRemoteFileOutboundGateway.handleRequestMessage(AbstractRemoteFileOutboundGateway.java:584)
	at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:136)
	at org.springframework.integration.handler.AbstractMessageHandler.doHandleMessage(AbstractMessageHandler.java:106)
	at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:74)
	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.sendInternal(AbstractMessageChannel.java:368)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:322)
	at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:292)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:187)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:233)
	at org.springframework.messaging.core.GenericMessagingTemplate.doSendAndReceive(GenericMessagingTemplate.java:47)
	at org.springframework.messaging.core.AbstractMessagingTemplate.sendAndReceive(AbstractMessagingTemplate.java:46)
	at org.springframework.integration.core.MessagingTemplate.sendAndReceive(MessagingTemplate.java:97)
	at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:622)
	at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceive(MessagingGatewaySupport.java:551)
	at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceive(MessagingGatewaySupport.java:519)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.sendOrSendAndReceive(GatewayProxyFactoryBean.java:661)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.invokeGatewayMethod(GatewayProxyFactoryBean.java:584)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.doInvoke(GatewayProxyFactoryBean.java:550)
	at org.springframework.integration.gateway.GatewayProxyFactoryBean.invoke(GatewayProxyFactoryBean.java:540)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:218)
	at jdk.proxy3/jdk.proxy3.$Proxy104.listRemoteFolder(Unknown Source)

Reproduce example: https://github.com/hantsy/spring-puzzles/blob/master/integration-sftp

Replace the "si.sftp.sample" with an empty String in this line, run this test it will throw above example.

[artembilan]

Try this as a workaround ".", I mean not empty string from remote path, but exactly a dot with the meaning current dir which in case of fresh session indeed is going to be a user home.
At least that's what I see with Apache MINA SSH server.

I agree that we are missing a respective unit test, but I wonder why this was not tested before we have gone GA?
We released a lot of milestones and a couple RCs these past months. It would be great if you come back to us with feedback before we go GA with bugs like this.

Thank you for understanding!